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THE GASOLINE AUTOMOBILE
PUBLISHERS OF BOOKS F O R_^
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Geo. B. Selden in his "Benzine Buggy.'
The present day motor car.
(frontispiece)
ENGINEERING EDUCATION SERIES
THE GASOLINE AUTOMOBILE
PREPARED IN THE
EXTENSION DIVISION OF
THE UNIVEESITY OF WISCONSIN
BY
GEORGE W. HOBBS, B. S.
INSTRUCTOR IN MECHANICAL ENGINEERING IN TH1
UNIVERSITY EXTENSION DIVISION, THB
UNIVERSITY OP WISCONSIN
BEN G. ELLIOTT, M. E.
I PROFESSOR OF MECHANICAL ENGIN
THB UNIVERSITY OF NEBRASKA
FIRST EDITION
EIGHTH IMPRESSION
TOTAL ISSUE, 18,000
McGRAW-HILL BOOK COMPANY, INC.
239 WEST 39TH STREET. ^ NEW YORK
LONDON: HILL PUBLISHING CO., LTD.
6 & 8 BOUVERIE ST., B. C.
1915
COPYRIGHT, 1915, BY THE
MCGRAW-HILL BOOK COMPANY, INC.
PREFACE
The purpose of this book is admirably expressed in the following
quotation taken from the Buick instruction book: "To derive the
greatest amount of satisfaction and pleasure from the use of his car the
driver should have a complete understanding of the mechanical principles
underlying its operation. Merely knowing which pedal to press or which
lever to pull is not enough. The really competent driver should under-
stand what happens in the various parts of the car's mechanism when he
presses the pedal or pulls the lever. He should know the cause as well
as the result."
When we consider the complexity of modern automobiles from a
mechanical standpoint, with the duties that are required of them,
together with the fact that the great majority of them are operated by
men with little or no experience in the handling of machinery, the
automobile stands as one of the most remarkable machines that the
ingenuity of man has ever produced. The operating expense of the
automobile has already assumed a large place in the budget of the
American people. Although it is so built that the owner may secure good
service from his automobile with very little knowledge of its construction,
still it is evident that an intimate acquaintance with its details should
enable him to secure better service at less expense and at the same time
to prolong the useful life of the car.
It is with the hope of increasing the pleasure of automobile ownership
and reducing the trouble and expense of operation that this book is
offered. It is planned primarily for use in the University Extension work
in Wisconsin, for the instruction of those who drive, repair, sell, or other-
wise have to do with motor cars. It is largely the outgrowth of a series
of lectures on the subject which were given in twenty-three cities of
Wisconsin during the past winter.
The thanks of the authors are especially due to Mr. M. E. Faber of
the C. A. Shaler Co. for assistance in preparing the section dealing with
tire troubles, to Prof. Earle B. Norris for much of the chapter on Engines
and for editing the manuscript and reading the proof, and to the many
manufacturers who have liberally assisted in the preparation of the work
by supplying their cuts and other material.
G. W. H.
MADISON, Wis.,
Sept. 15, 1915.
vu
CONTENTS
CHAPTER I
GENERAL CONSTRUCTION
ART. PAGE
1. The steam propelled car 1
2. The electric car 1
3. The gasoline car 2
4. Types of cars 2
5. The chassis 2
6. The frame . 6
7. The springs 6
8. The front axle : 8
9. The steering gear 10
10. The rear axle 12
11. The differential 13
12. The power plant and transmission 14
13. The torque arm 15
14. Strut rods 16
15. Brakes 16
16. Wheels 18
17. Tires 19
18. Rims 20
19. The speedometer drive 21
20. Control systemr 23
CHAPTER II
ENGINES
21. What is an explosion? 25
22. Cycles 25
23. The four-stroke cycle 26
24. The order of events in four-stroke engines 27
25. The mechanism of four-stroke engines 28
26. Valve timing and setting 29
27. Valves 30
28. Valve arrangements 33
29. The Knight engine 34
30. The rotary valve 34
31. Two-stroke engines 35
32. The flywheel 38
33. Ignition .39
34. Clearance and compression ' 39
35. Piston displacement 39
36. Cylinder cooling 40
37. The muffler • 40
38. Horse power of engines 41
ix
x CONTENTS
CHAPTER III
POWER-PLANT GROUPS AND TRANSMISSION SYSTEMS
39. Single- and multi-cylinder engines 43
40. Power plant and transmission arrangements ". . . . 44
41. Modern automobile power plants 50
42. Constructional features of four- and six-cylinder engines 56
43. Eight- and twelve-cylinder power plants 60
44. Clutches 64
45. Change gear sets 66
46. Planetary gearing 67
47. Universal joints and drive shaft 69
48. Final drive 70
49. Types of live rear axles 71
CHAPTER IV
FUELS AND CARBTJRETTING SYSTEMS
50. Hydrocarbon oils 75
51. Fractional distillation of petroleum 75
52. Principles of vaporization 76
53. Heating value of fuels 79
54. Gasoline gas and air mixtures 79
55. Principles of carburetor construction 79
56. Schebler, model L carburetor 82
57. Schebler, model R 84
58. The Holley model H carburetor 86
59. Holley model G 87
60. Stewart model 25 89
61. Kingston model L 90
62. Marvel carburetor 91
63. Stromberg, model H 94
64. Zenith model L 94
65. Rayfield model G 95
66. Carter model C 97
67. General rules for carburetor adjustment 98
68. Carburetor control methods 99
69. The gravity feed system 99
70. The pressure feed system 100
71. The vacuum feed system 100
72. Intake manifolds 102
73. Care of gasoline 102
CHAPTER V
LUBRICATION AND COOLING
74. Friction and lubricants 103
75. Cylinder oils 104
76. Viscosity 104
CONTENTS xi
AET. PAGE
77. Flash point 104
78. Fire test and cold test 104
79. General notes on lubrication 104
80. Splash system of engine lubrication 106
81. Splash system with circulating pump 106
82. Full forced feed system Ill
83. Mixing the oil with the gasoline 113
84. Selection of a lubricant 113
85. Directions for lubrication 114
86. Cylinder cooling 117
87. Water cooling systems 117
88. Air cooling 122
89. Cooling solutions for winter use 123
CHAPTER VI
BATTERIES AND BATTERY IGNITION
90. Fundamental electrical definitions 127
91. Direct and alternating current 127
92. Dry batteries 128
93. Storage batteries 128
94. Series and parallel connections 129
95. Battery connections for ignition purposes 130
96. Simple battery ignition system 130
97. The three terminal coil 132
98. Timers 135
99. Spark plugs 135
100. Master vibrators 136
101. The high tension distributor system 137
102. The Connecticut automatic ignition system 139
103. The Atwater Kent system 141
104. The Westinghouse ignition system 144
105. The Delco system of ignition 147
106. The Remy-Studebaker ignition system 149
107. Spark advance and retard 151
108. Automatic spark advance 151
CHAPTER VII
MAGNETOS AND MAGNETO IGNITION
109. Principles of magnetism : 153
110. Mechanical generation of current 155
111. Low and high tension magnetos 156
112. Armature and inductor types 156
113. Remy model P magneto 157
114. The Connecticut magneto 160
115. Dual ignition systems 160
116. Eisemann high tension dual ignition 161
117. Eisemann automatic spark control 163
118. The K-W high tension magneto 163
rii CONTENTS
ABT. PAGS
119. The Dixie magneto 16f>
120. The Bosch high tension magneto 167
121. The Bosch dual system 170
122. Bosch two-independent system 173
123. The Ford magneto and ignition system 174
124. Magneto speeds 175
125. Timing the magneto 176
126. Battery vs. magneto ignition 177
127. General suggestions on magnetos 177
128. Common magneto ignition definitions 177
CHAPTER VIII
STARTING AND LIGHTING SYSTEMS
129. Starting on the spark 179
130. Mechanical starters 180
131. Air starters 180
132. Acetylene starters 180
133. Electric starters 181
134. Storage batteries 181
135. Battery charging • 185
136. Wiring systems 187
137. The Ward-Leonard system 187
138. The Delco system 190
139. Gray and Davis starting and lighting systems 193
140. Wagner starting and lighting system 197
141. The Westinghouse single-unit system 199
142. Westinghou.se two-unit system 200
143. The U. S. L. electric starting and lighting system 204
144. Jesco single-unit electric starter and lighter 205
145. Care of starting and lighting apparatus. 207
146. Starting motor troubles 208
147. Generator troubles 209
148. Battery troubles 209
149. Winter care of batteries 209
150. "Don'ta" on starting equipment 210
CHAPTER IX
AUTOMOBILE TROUBLES AND REMEDIES
151. Classification of troubles 213
152. Power plant troubles 214
153. Mechanical troubles in engine 216
154. Carburetion troubles 221
155. Ignition troubles 223
156. Lubricating and cooling troubles 226
157. Starting and lighting troubles 228
158. Transmission troubles 228
159. Chassis troubles . . 229
CONTENTS xiii
CHAPTER X
OPERATION AND CARE
ART. PAGE
160. Preparations for starting 231
161. Cranking 231
162. How to drive 232
163. Use of the brakes 233
164. Speeding 234
165. Care in driving 234
166. Driving in city traffic 235
167. Skidding 236
168. Knowing the car 237
169. The spring overhauling 238
170. Washing the car 240
171. Care of tires 240
172. Tire troubles 243
173. Figuring speeds 247
174. Interstate regulations 248
175. Canadian regulations 249
176. Touring helps-route books 250
177. Cost records 250
INDEX . . 255
THE GASOLINE AUTOMOBILE
CHAPTER I
GENERAL CONSTRUCTION
Automobiles may be classified according to the type of power plant
used, as steam, electric, and gasoline; or they may be divided into two
classes according to use, as pleasure cars and commercial cars.
1. The Steam Propelled Car. — The steam engine has the advantage of
-flexibility. All operations such as starting, stopping, reversing, and
acquiring changes of speed can be done directly by throttle control.
By opening or closing the throttle, more or less steam is supplied to the
engine, and the power is increased or decreased in proportion. When
climbing a hill, all that is necessary to do is to give the engine more steam
and consequently more power. The advantage of the steam engine in
being able to start under load eliminates the clutch and also the trans-
mission or change speed gears, the engine being connected directly to
the rear axle.
The disadvantage of the steam engine is that it is necessary to fire up
before starting, in order to generate enough steam to run the engine and
propel the car. The steam machine requires large quantities of water
to form the steam and that means frequent refilling of the water tank.
They also require constant attention to the water and fuel pumps. The
burning of the fuel under a boiler to generate the steam introduces an
element of danger from fire and also makes the steam plant less efficient
than the internal combustion engine.
2. The Electric Car. — The advantages of the electric car are similar to
those of the steam car inasmuch as it is very flexible and can be controlled
entirely by the controlling levers. By cutting out or in resistance, more
or less current is supplied to the motor and the power of the motor is
proportional to the flow of the current. The electric car is especially
adapted to the use of women and children in cities. It is easy riding,
clean, and very quiet.
The disadvantages are that it is not suitable for long drives, heavy
roads, or hilly country. On one charge of the battery the average car
will run from 50 to 100 miles^ ^depending on the speed and condition
of the roads. If the car is run at high speed, the battery will not
1
2 THE GASOLINE AUTOMOBILE
drive the car as far as it will when running at moderate rate. This
car is also limited to localities where there are ample facilities for charging
the storage batteries.
3. The Gasoline Car. — The gasoline engine is much more economical
than either the steam or electric, and after being once started has great
flexibility. It is also better adapted for touring purposes than either
of the others and does not require any more attention from the operator.
The average car carries enough fuel to run it 200 to 400 miles
without a stop and then it is necessary to fill the gasoline tank only,
with an occasional quart or two of water for the radiator. With proper
care, the engine will run as long as the gasoline supply and electrical
system will hold out.
The disadvantages of the gasoline engine as compared with the steam
engine or electric motor are, first, the gasoline engine is not self-starting;
and, second, it lacks overload capacity. This means that some method of
changing the speed ratio of the engine to the rear wheels is necessary in
order to acquire extra power for climbing hills, for heavy roads, and also
for reversing the car, as it is not possible to reverse the ordinary four-
stroke automobile engine. The gasoline engine will not start under load,
which necessitates the use of a clutch, so that the engine can be started
and speeded up before any load is thrown on. Apparently there are a
great many disadvantages to the gasoline engine but in reality they are
very few, for with the proper handling of the spark and throttle control-
ling levers it is not necessary to keep continually changing gears. The
speed change lever need not be used except for starting, stopping, hill*
climbing, and on bad roads.
4. Types of Cars. — In general, the parts of the pleasure and commercial
cars are the same except that the pleasure cars are built much lighter than
the commercial cars. In the pleasure car everything is planned for
comfort and speed, while the commercial car is built for heavy loads and
is generally intended to be driven at low speed.
The principal body types of pleasure cars are, the limousine, the
touring car, the coupe, and the roadster, as shown in Fig. 1.
The commercial cars are built for light, medium, and heavy duty. A
few of the commercial types are shown in Fig. 2.
The cycle car is a name commonly given to small cars which have less
than 70 cu. in. piston displacement or a tread of less than 56 in.
5. The Chassis. — The principal parts of the gasoline automobile are
the frame, springs, axles, wheels, power plant and auxiliaries, clutch,
transmission system, controlling apparatus and body. The chassis, as
shown in Fig. 3, includes all parts with the exception of the body and its
accessories. The functions and types of these parts will be taken up
separately.
GENERAL CONSTRUCTION
THE GASOLINE AUTOMOBILE
JLJLJ
HEAVY TRUCK
LIGHT TRUCK
MEDIUM TRUCK
2.— Types of commercial canp,
GENERAL CONSTRUCTION
Radiator
Power plant
-Clutch
•Universal joint
-Control levers
-Drive shaft
Torque crrm-
or
Torque rod
Muffler
Brake equalizers
3 rake
-Storage baffery
mmmm
Universal joint
Change aears
Brakes
FIG. 3.— Chassis of the Studebaker "Six.
6 THE GASOLINE AUTOMOBILE
6. The Frame. — The automobile frame is a very important part of
the car, due to the fact that it supports the power plant, transmission
mechanism, body, etc. The frame is attached to the springs, which in
turn are fastened to the axles. Frames are made either of wood or metal
.or a combination of the two. The metal frames are usually of channel-
section steel. The wooden frames may be either of the solid timber type
or of laminated strips glued together and sometimes reinforced by steel
strips. This type is very strong and light and does not transmit so much
FIG. 4. — Channel steel frame.
of the vibration as the steel frame. Figure 4 shows a pressed steel channel-
section frame. Figure 5 shows a frame made from second-growth ash and
used on the Franklin car.
7. The Springs. — The frame of the automobile is supported by
laimated leaf springs. Coil springs are used only in places where a great
deal of strength is needed in a small space and where quick action is
required. The springs under the frame of an automobile must be gradual
FIG. 5. — Franklin wood frame construction.
and easy in their action, and this is why the laminated leaf spring is used.
The strength and resilience of the leaf spring can be varied by changing
the number of leaves or by varying the width or length of the leaf. It
also has an advantage over the coil spring in that if one leaf breaks the
spring is still serviceable, while in a coil spring if a coil breaks the spring
is no longer of any use.
The laminated spring is built up of a number of leaves varying in
length, the longest leaf being on the concave side of the spring and the
GENERAL CONSTRUCTION
g THE GASOLINE AUTOMOBILE
other leaves built on this one in the order of their length. The ends of
the long leaf are bent around to form eyes so that they can be fastened to
the frame by a clevis or other means.
The laminated leaf springs, as shown in Fig. 6, are built in the follow-
ing forms: cantilever, semi-elliptic, three-quarter elliptic, full-elliptic,
and platform springs.
The Cantilever spring is fastened flexibly to the frame at one end and
the center and carries the axle at the other end. There is another
type of (jantilever spring which has a single rigid fastening to the frame.
This is also called a quarter-elliptic spring.
The (semi-elliptic spring usually has its center fastened to the axle
while thl two ends support the frame. This type of spring is generally
used to ^upport the front end of the car, because this type has the least
amount of side-sway. Since the front axle is used for steering purposes, a
great amount of flexibility is not desired.
The three-quarter elliptic spring consists of a semi-elliptic member,
to one end of which is attached a quarter-elliptic member. This type
is supported in the middle of the semi-elliptic spring and is connected
to the frime at one end of the semi-elliptic and the free end of the quarter-
elliptic sbrings.
The ifull-elliptic spring consists of two semi-elliptic springs con-
nected together at the end, supported at the middle of one semi-elliptic
and carrying the load at the middle of the other. Either the three-
quarter or the full-elliptic types have greater flexibility than the semi-
elliptic tiype.
The platform spring consists of three semi-elliptic springs fastened
together. Two of the members are parallel to the sides of the car arid
the third is inverted and is parallel to the cross members. The car frame
is attached to the front end of the side members and to the middle of the
cross member. The middle of the side members rests on the spring
8. The Front Axle. — The front axle consists of the center, the knuckles,
a steering arm, a third arm, a plain arm, and the tie rod. The centers
are either I-beam, as shown in Fig. 7 or tubular as in Fig. 8, and they
may be either straight or dropped center types. Square centers are
sometimes used on heavy trucks.
The }-beam centers are made either of drop forgings or of cast steel
and are heat-treated to do away with brittleness and give strength and
toughness. The tubular centers and tie rods are made from the best
high-grade seamless steel tubing and the yokes are either pinned or
brazed on the ends of the tubes. In the I-beam centers the yokes form
a part of the forging or casting. The I-beam construction is the strong-
est but is not quite so flexible as the tubular center.
GENERAL CONSTRUCTION 9
The front wheels are fastened on the spindle of the knuckle and run
on cup-and-cone ball bearings or on roller bearings as shown in Fig. 7.
The spindle is set so that the front wheels have a camber of about 2 in.,
that is, the tops of the wheels are about 2 in. farther apart than the
FIG. 7. — I-beam front axle construction.
bottoms of the wheels. This is to conform to the crown of the road and
to bring the point of contact between the tire and the road in line with
the king-bolt.
In order to make the car steer easier and have a tendency to run
straight ahead, the front wheels should toe in from % to ^ in. This is
done by adjusting the length of the tie rod.
FIG. 8. — Tubular front axle.
The knuckles are fastened in the axle yokes by king-bolts and are
free to swing about 35° either way from the center line of the axle.
This is necessary in order to allow the wheels to follow a curve when turn-
ing. Between the top of the axle yoke and the knuckle there should
10
THE GASOLINE AUTOMOBILE
be a ball or roller bearing or a renewable bronze washer to carry the
load and yet allow the knuckle to turn easily.
The king-bolt should fit in a bronze bearing in order to insure easy
movement and a small amount of wear. The steering and third arms,
which are generally combined in a single forging, are keyed to one
knuckle. The third arm is connected by the tie rod to the plain arm,
which is keyed to the other knuckle. The general layout of the steering
apparatus is shown in Fig. 9. The steering arm is connected by the drag
link to the pitman arm or steering lever on the base of the steering
gear.
Steerinq wheel
Sfeer/na column -:
« Pitman arm
—-Drag link
Fig. 9. — Arrangement of steering apparatus.
9. The Steering Gear. — The steering gear is the part of the mechan-
ism that operates on the knuckles to turn the front wheels in response
to movements of the hand wheel.
Figure 10 shows the essential parts of a double worm steering gear.
Inside the steering column is the steering tube, the upper end of which
is connected to the hand wheel while the lower end carries a double-
threaded worm. The worm meshes with two half-nuts, one with a right-
hand and the other a left-hand thread. Two rollers, which are attached
to the yoke that operates the pitman arm or steering lever, bear against
the lower ends of the half-nuts. The operation is as follows: Turning
the hand wheel turns the tube and worm in the same direction, which
causes one half-nut to rise and the other to descend. This pushes one
roller down and lets the other rise. The yoke is given the same motion
GENERAL CONSTRUCTION
11
and transmits it to the pitman arm, which pushes or pulls on the drag
link and thus turns the knuckle and wheels.
Sector
Spark lever
/ Throttle, lew
X js'
rod
—Stationary tube
•Throft/e fube
"•Adjusting nut
— Grease plug
, Throttle gear
— - -fy&r/c a ear
FIG. 10. — Double worm steering mechanism.
Figure 11 shows the worm-and-gear type. The worm is fastened to the
steering tube and is turned with the hand wheel. The gear shaft carries
the pitman arm, which connects to the knuckle steering arm by the
drag link.
12 THE GASOLINE AUTOMOBILE
These steering gears are non-reversible, because while the action
of the hand wheel is readily transmitted to the front wheels the jarring
of the front wheels on rough roads can not be transmitted back to turn
the hand wheel.
Grease Cup
Worm
Gear
FIG. 11. — Worm-and-gear steering mechanism.
10. The Rear Axle. — The rear axle must carry this end of car and
also provide means of giving power to the rear wheels to propel the car.
This is done in two general ways, and the corresponding types of axles
are called "dead" and "live" axles.
Figure 12 shows a truck chassis with a dead rear axle. It is somewhat
similar in construction to the ordinary wagon axle, as it is made up of a
FIG. 12. — Heavy truck, chassis with dead rear axle.
solid bar with spindles machined on the ends for the wheel bearings.
The wheels have large sprockets on the inside which are driven by chains
from other sprockets on the ends of a "jackshaft" near the middle of the
car. This type of axle is used principally on heavy trucks where it is
GENERAL CONSTRUCTION 13
necessary to have a solid construction and provide for a large reduction
in speed.
For pleasure cars, the live axle is generally used. The general
arrangement of a car with a live axle was shown in Fig. 3. In Fig. 13 is
shown in detail the construction of a typical live axle. In this type the
axle turns and drives the rear wheels with it. The axle is surrounded
by a stationary housing which supplies the bearings for the wheels and
the axle and which also supports the car through the springs. The
live axle receives its power near the center, usually through a set of
bevel gears which give the desired speed reduction and also make the
necessary right angle change in the power transmission.
BE4R/NG5
DffUM
FIG. 13. — Live rear axle.
11. The Differential. — Some provision has to be made to drive the
rear wheels positively in either direction and yet allow one wheel to run
ahead of the other when turning a corner. This is done by dividing the
live rear axle at the center and connecting the two halves by a differential
gear, the details of which are shown in Fig. 14. Each half of the live
axle (called the main shaft in Fig. 14) has a bevel gear on its inner end.
These bevel gears face each other and are called the differential gears.
They are connected by from two to four differential pinions spaced at
equal distances around the circle. The power is applied at the centers
of these differential pinions so that they act like the doubletrees or
eveners on a team of horses, allowing one wheel to run ahead of another
or to lag behind but still maintaining an even pull on the two differential
gears. Referring to Fig. 14, the power from the engine is brought back
to the driving, pinion and this delivers it to the large gear called the bevel
ring. This bevel ring is fastened to the differential case, which, therefore,
receives the power from the bevel ring. The differential case turns the
spider with it and, as this spider carries the differential pinions, these
pinions are carried around with a force applied at their centers. On a
14
THE GASOLINE AUTOMOBILE
straight road the differential case, the spider, the differential pinions
and the differential gear all revolve as one mass and there is no internal
action in the differential. The differential pinions pull equally on the two
differential gears on each side of them and they all revolve together. In
FIG. 14. — Differential gear.
turning a corner the outer wheel has farther to go and hence must run
faster. This makes the one differential gear turn faster than the other.
This causes the differential pinions to revolve on their axes, but they
still continue to deliver power equally to the two wheels.
FIG. 15. — Arrangement of power plant and transmission system.
12. The Power Plant and Transmission'.— Figure 15 shows a typical
arrangement of the power plant and the power transmission system.
The engine is generally placed in the front end of the car, both for ac-
cessibility and to balance the weight of the passengers in the rear part
GENERAL CONSTRUCTION 15
of the car. The engine is the most important part of the car. Its
purpose is to transform the heat energy of gasoline into mechanical
energy at the crank shaft for the purpose of driving the car. The power
is delivered to the flywheel, from which the clutch takes it and passes it
back to the transmission. In the transmission case is a system of gears
for reducing the speed from the engine and increasing the turning force
for starting purposes or for heavy driving, as in sand or on hills.
The power plant is mounted on the frame of the car, while the rear
wheels which are to finally receive and use the power are flexibly con-
nected to the frame by springs. We must, therefore, have a flexible
arrangement for taking the power from the power plant to the rear
axle. This is usually accomplished by means of a propeller shaft and
one or two universal joints (see Fig. 15). A universal joint is merely a
double-hinged shaft connection (see Fig. 16) permitting the lower end of
the propeller shaft to swing at will with the
rear axle and yet receive power from the
engine.
In the t,car of Fig. 15 the engine and
transmission are carried in the frame of the
car and the first universal lies just back of the
transmission. In the car of Fig. 3 the trans-
mission with its change gears is placed just in „
Tii FlG- I6- — Universal joint,
front of the rear axle and is fastened solidly
to the rear axle housing. This places both universal joints and the
propeller shaft between the engine and the transmission.
In addition to the engine proper, the power plant contains a number
of accessories necessary for the operation of the engine, such as the
lubricating system, the ignition system, the carburetor, the cooling system,
and the starting system. In the so-called unit power plant the clutch
and change gears are contained in a single unit with the engine. All
these accessories will be taken up in the later chapters.
In heavy trucks the system of power transmission is somewhat
different from the pleasure car system just described. The power from
the engine is carried through the clutch and back to the transmission
located in the center of the chassis, as shown in Fig. 12. Here the power
is turned at right angles in the rear part of the transmission and is given
to a jackshaft lying across the car. The sprockets on the outer ends of
this jackshaft drive the rear wheels through two chains. No universal
joints are needed in the final drive, as the chains allow for the free motion
of the rear axle.
13. The Torque Arm. — When the brakes are used in stopping a
car, the brakes, being carried by the rear axle housing, tend to carry this
Jiousing around with the wheels, likewise, the action of *he propeller
16 THE GASOLINE AUTOMOBILE
shaft and the bevel pinion in driving the rear axle (see Fig. 14) tend to
turn the axle housing over backward with the same force that is exerted
on the bevel ring. This twisting action or "torque" must be taken
care of in some way. This can be done by torsion rods as in Fig 15,
or by a single bar called a torque arm or by a torsion tube around the
propeller shaft, or it can be left entirely to the springs to take care of this
action. If the torque is taken up by a housing around the propeller
shaft as in Fig. 17, this tube is called the "third member" of the rear axle
system and is securely bolted to the rear axle housing. This system does
away with one universal joint, as only one at the front extremity of the
propeller shaft is used.
Strut roof-
FIG. 17. — Rear axle with torque tube and strut rods.
14. Strut Rods. — In order to preserve the alignment of the wheels or
to keep one wheel from getting ahead of the other, strut rods are fastened
to the brake flanges or spring seats, and extend to the front end of the
third member as in Fig. 17 or to some part of the frame.
15. Brakes. — Brakes which act on the rear wheels are either of the
contracting or expanding band type or the expanding shoe type.
Figure 18 shows the general layout. This is known as a double
internal type of brake. A steel brake drum is fastened securely to the
wheel. Both bands expand and put pressure on the inside of the drum.
The outside band, or the one next the wheel, is the emergency brake and
is operated by a hand lever. The other, the service brake, is under the
control of the driver through the medium of the foot pedal. The brake
bands are carried by brake flanges near the ends of the rear axle housing.
The two sets are entirely independent of each other. Another type of
GENERAL CONSTRUCTION
17
internal expanding band brake that uses two brake drums is shown in
Fig. 19. The action is similar to the above. In this case the smaller
SERVICE BRAKE
SERVICE BRAKE LEVER
EMERGENCY BRAKE LEVE
FIG. 18. — Double internal brake with single drum.
EMERGENCY BRAKE LEVER
FOOT BRAKE
EMERGENCY BRAKE
NULAfl BALL BEARINGS
RELEASE SPRINGS
FIG. 19. — Double internal brake with two drums.
band is used for the emergency. Figure 20 shows a type of brake known
as the internal-external brake. There are two bands working on the
18
THE GASOLINE AUTOMOBILE
Brake
facing
same drum. One set contracts around the outside of the drum and the
other set expands against the inner circumference. The outer band
constitutes the service or foot brake and
the inner band the emergency brake.
All bands, either contracting or ex-
panding, are faced on the rubbing side
with an asbestos preparation that is
capable of standing a great amount of
wear and is not easily burned out. Some
types that use the expanding shoe have
a cast-iron shoe that is pressed against
the inside of the steel drum on the wheel.
A typical mechanism for operating
the expanding shoes or drums is clearly
shown in Fig. 18, where the emergency
band is shown expanded while the ser-
vice brake is in the running position.
16. Wheels. — Automobile wheels are
classified as artillery wheels (with wooden
spokes), wire wheels, and cast- or pressed-
steel wheels, the latter being limited to
heavy duty trucks.
Artillery Wheels. — The artillery wheel, shown in Fig. 21, is built
of second-growth hickory. The spokes are fastened together at the
Expanding
Contracting
"" band
FIG. 20. — Internal-external
brake.
Felloe ,
Demountc
C/arnp \
rim Fe//oe. bane/
Demountable rim Felloe band
FIG. 21.— Artillery wheel.
FIG. 22.— Wire wheel.
hub of the wheel by a series of interlocking mortise-and-tenon joints and
the outer ends are turned down to fit in holes in the wooden felloe band.
GENERAL CONSTRUCTION 19
The hub casting, which serves to hold the inner end of the spokes, also
acts as the bearing housing for the hub bearings, on which the wheel
revolves.
Wire Wheels. — The wire wheel is shown in Fig. 22. On account of
the scarcity of second-growth hickory, which is the only acceptable
material for artillery wheels, some companies are building wire wheels
which are modifications of the bicycle wheel. Wire spokes are inter-
laced between the hub and rim in such a manner that the wheel is held
rigid and withstands both the direct loads and side strains.
In the artillery wheel, the load is carried by the spokes on the under
side. In the wire wheel, the load is carried by the spokes above the
hub.
The advantages claimed by the wire wheel manufacturers are that the
wheel is reduced in weight about 30 per cent. ; is more resilient, which
makes an easier riding car; will stand greater radial strain; and is fully as
strong as the artillery wheel.
Wearing Surfa ^^^^ /Breaker Strips
Inner Tube
Piano W:
FIG. 23. — Section of pneumatic tire.
17. Tires. — The tires used on pleasure cars are usually of the pneu-
matic rubber type. Some are being filled with a spongy substance that
makes them more of a cushion form and some have bridges of para
rubber instead of an air cushion. The lighter commercial cars use solid
rubber tires, the heavier trucks use steel tires, while some are using
wooden blocks. The wooden blocks and steel tires can be used only on
the very low-speed trucks on account of there being no resilience in tires
of these types.
The pneumatic tire serves as a good shock absorber and eliminates
a large portion of the road vibrations and jars before they reach the
mechanism of the car.
The general construction of the tire is shown in Fig. 23. Several
layers of heavy canvas (friction fabric) are wound around two circular
wire cables (beads) in the shape of a tire. This forms the foundation,
20
THE GASOLINE AUTOMOBILE
which is filled with rubber gum to form the carcass of the tire. Around
the carcass the cushion is built, which is an extra thickness of com-
pounded rubber held in place by a double layer of canvas. This is called
the breaker strip. Outside of this comes the tread. The tread is the
part that comes into contact with the road and takes the wear. This
whole structure is then vulcanized to make a solid unit.
The inner tube, which is merely a rubber bag with a check valve
to hold the air, is inserted in the casing and the casing is fitted on the
FIG. 24. FIG. 25.
FIGS. 24 AND 25. — Types of detachable rims.
rim in such a way that when the pressure is applied the bead grips the
rim, and the flanges on the rim prevent the tire from sliding off sideways.
18. Rims. — Rims may be classified as clincher, detachable, and
demountable, or a combination of two of these. The cuts shown in
Figs. 24, 25, and 26 show sections of the Goodyear rims. Figure 24
illustrates the detachable rim of two parts. The side ring can be easily
removed from the groove by a screw-driver. The higher the inflation
pressure in the tire the harder the side ring hugs the groove. This
rim is used to a great extent on electric pleasure cars.
FIG. 26.— Demountable-detachable rim.
Figure 25 shows a heavier type of detachable rim, quite general
on gasoline pleasure cars.
Figure 26 shows a rim which has both the demountable and detach-
able features combined. With demountable rims, an extra rim with
tire fully inflated may be carried. In case of a blow-out, the damaged
tire and its rim may be quickly removed and the spare rim and tire put
on. This saves considerable time in cases of tire trouble.
Figures 27 and 28 show the rim made by the General Rim Co. This
GENERAL CONSTRUCTION
21
is a demountable rim and is locked on the rim at a single point. To
remove the rim from the wheel the toggle nut is turned to its
lowest position on the end of the clamping bolt, as shown in Fig. 28.
This draws the clamping ring into the groove and the rim is re-
leased and ready for removal. To replace the rim merely reverse this
operation.
Felloe band
Felloe
Demountable rim
Toggle nut
FIG. 27.
Felloe \ \ ^^^^ \
Felloe bane/ \ / UlP C/amp
Demountable rim Clomping boft
FIG. 28.
FIGS. 27 AND 28. — Demountable clincher rim.
Figure 29 shows sections of the clincher rim as used on the Ford
car, and also shows the method of removing the tire from the rim.
19. The Speedometer Drive. — Some device for indicating the speed
should be installed on every car as the cost of one fine will purchase a
reliable speedometer.
Second Position
of Tire Tool
FIG. 29. — Method of removing clincher tires.
The drive may be taken from a gear attached to the transmission,
as shown in Fig. 30, or from a similar attachment on one of the front
wheels.
Figure 31 shows a speedometer drive installed in the spindle of
the steering knuckle and driven from a plate under the hub cap. This
eliminates the use of an exposed gear and requires no attention except
proper lubrication. Care should be used to see that the drive plate is
properly replaced if the hub cap is removed for any reason.
22
THE GASOLINE AUTOMOBILE
FIG. 30. — Speedometer drive from transmission.
SPEEDOMETER GEAR
SPEEDOMETER GEAR BUSHING
SPEEDOMETER DRIVE SH/
SPEEDOMETER DRIVE PLATE
H
SPEEDOMETER PJNIOM
OOMETER PINION BUSHING
SPEEC
SPEEDOMETER END CONNECTION
FIG. 31. — Speedometer drive through knuckle spindle.
GENERAL CONSTRUCTION
23
20. Control Systems. — Figures 32 and 33 show the two prevailing
control systems. Figure 32 shows the left-hand drive and center con-
trol system generally used on cars with sliding gear transmissions.
SPARK CONTROL LEVE
IGNITION SWITC
SPEEDOMETER
CLUTCH PEDAL
ACCELERATOR PEDAl
/ REGULATOR
SERVICE BRAKE PEDAL
EMERGENCY BRAKE LEVER
^CONTROL LEVER
FIG. 32. — Left-hand drive, center control.
FIG. 33.— The Ford control.
The operation is as follows: The left-hand pedal operates the clutch
and the other pedal the foot or service brake. The right-hand Jever
operates the emergency brake. The left-hand lever operates the change
gears as follows: To the left and ahead for reverse, to the left and back
24 THE GASOLINE AUTOMOBILE
for low speed ahead, to the right and ahead for second speed ahead, and
to the right and back for third or high speed ahead. This order of
events is not standard for all cars. Every car has its own system of
shifting gears.
Figure 33 shows the Ford control system. This system consists of
three foot pedals and one hand lever. The pedal on the left operates
the clutch and controls the high and low speed. The hand lever also
operates the clutch and when drawn all the way back sets the emergency
brake. With the hand lever forward and left pedal up it is then in
high gear. To get low speed ahead, the left pedal is pressed all the
way forward; halfway in releases the clutch? The second or middle
pedal marked "R" operates the reverse mechanism. To reverse the
car the hand lever must be in a vertical position or the clutch pedal half-
way in; then pressing on the reverse pedal drives the car backward.
The right-hand pedal operates the foot or service brake, which is on
the transmission.
The chapters to follow will treat in detail of the various parts of
the car, their construction, methods of operation, and maintenance.
CHAPTER II
ENGINES
21. What is an Explosion? — Practically all gasoline engines are
driven by explosions which take place within the cylinder of the engine
and drive the piston, thus causing rotation of the revolving parts of the
engine. These explosions are in a way very similar to the explosions of
gunpowder or dynamite. When a charge of gunpowder is fired in a
cannon or gun, the gunpowder burns and produces gases which exert a
tremendous pressure on the shell and force it from the gun.
Practically any substance that will burn can be exploded if under the
proper conditions. An explosion is merely a burning of some material
taking place almost instantaneously, so that a great amount of heat is
generated all at once. When any substance burns, it unites rapidly
with oxygen from the air. If we want to get an explosion, it is necessary
to have the fuel very finely divided and carefully mixed with air, so that
the burning can be very rapid. Then, if we start the fuel burning, by an
electric spark or any other means, the flame instantly spreads throughout
the mixture and an explosion occurs. In a gasoline engine we take in
gasoline vapor mixed carefully with air. This mixture is then exploded
inside the cylinder of the engine. The force of this explosion drives the
piston and the motion is transmitted through the connecting rod to the
crank. To make the process continuous and keep the engine going, it is
necessary to get rid automatically of the gases from the previous ex-
plosion and to get a fresh charge into the cylinder ready for the next
explosion. This process must be carried out regularly by the engine, in
order to keep it running.
22. Cycles. — As we have just seen, an engine must supply itself with
an explosive mixture so that the force of the explosion will cause the
engine to move, and it must get rid of these dead gases and get in a fresh
charge of gas and air and explode this so as to keep up the motion.
There are in use at the present time two principal systems of performing
this series of operations. These systems, or rather the series of opera-
tions, are called cycles, and the engines are named according to the
number of strokes it takes to complete a cycle. These two cycles, or
systems of engines, are the four-stroke cycle and the two-stroke cycle.
Remember that a cycle refers to the series of operations the engine
goes through. In the four-stroke cycle there are four strokes or two
revolutions. In the two-stroke cycle there are two strokes or one revolu-
5 25
26 THE GASOLINE AUTOMOBILE
tion. Many people leave out the word stroke and talk of "four-cycle
engines" and "two-cycle engines." This causes the misunderstanding
that many people have as to just what a cycle really is. A better way is
to call them "four-stroke. engines" and "two-stroke engines."
23. The Four-stroke Cycle.— Figures 34, 35, 36 and 37 show an engine
which operates according to the four-stroke cycle. The engine shown
here is a vertical engine, that is, the cylinder is placed above the crank
shaft (instead of being at one side) and the piston moves up and down
in the cylinder. This is the prevailing form for automobile engines.
SPARK PLUG
'INLET VALVE
SUCTION STROKE
FIG. 34.
COMPRESSION STROKE
FIG. 35.
Any engine consists of four principal parts: the cylinder, which is
stationary and in which the explosion occurs; the piston, which slides
within the cylinder and receives the force of the explosion; the connecting
rod, which takes the force from the piston and transmits it to the crank;
and lastly the crank, which revolves and receives the force of the explosion
as the piston goes in one direction, and which then shoves the piston
back to its starting point. A four-stroke engine has a number of other
minor parts, whose uses will be brought out presently. This engine uses
four strokes of the piston to complete the series of operations from one
explosion to the next, and is therefore said to operate on the four-stroke
cycle, or it is said to be a "four-stroke" engine. The first illustration,
Fig. 34, shows the engine just drawing in a mixture of gas and air. This
is continued until the piston gets clear down to the bottom of the stroke,
ENGINES
27
and the cylinder is full of this explosive mixture. This operation is called
the suction stroke. Then the valves are shut, as in Fig. 35, and the piston
is forced back to its top position. This squeezes or compresses the gas
into a space left in the top of the cylinder, and this process of compressing
it is called the compression stroke. After the piston gets to the top, the
gases are ignited or set fire to and burn so quickly that an explosion
results and the piston is driven down again, as in Fig. 36. This is called
the expansion or working stroke. When it reaches the bottom of the
stroke, another valve is opened, and while the piston is returning to the
WORKING STROKE
FIG. 36.
EXHAUST STROKE
FIG. 37.
top position it forces out through this valve the burned gases which occupy
the cylinder space. This is the exhaust stroke. The engine is now ready
to repeat this series of operations. These operations have taken two
'revolutions or four strokes. A stroke means a motion of the piston
from either end of the cylinder to the other end. Consequently, there
are four strokes in the cycle of operations of this engine, and we therefore
call it a four-stroke engine.
24. The Order of Events in Four-stroke Engines. — The various parts
or events in the four-stroke cycle are shown on the diagram of Fig. 38.
This shows the two revolutions of the four -stroke cycle divided up so as to
show the crank positions when the different events occur. The diagram
is drawn for a vertical engine with the crank revolving to the left, as
shown on the engine of Figs. 34 to 37. This is the direction of rotation
28 THE GASOLINE AUTOMOBILE
of an automobile engine to a person in the car looking forward toward the
^Starting at the top of the diagram, we have just exploded the charge
and as the crank swings over to the left the gases are expanded. Before
the crank reaches the bottom, the exhaust valve is opened. This is
kept open while the piston is returned to the top. The inlet valve is
then opened and the suction stroke occurs as the crank and piston again
descend. Just after the crank passes the bottom, the inlet valve closes.
Both valves being now closed, the charge is compressed as the crank and
piston rise again to the top. A short time before reaching the top,
ignition occurs. This should be just far enough before the top so that
the explosion or combustion is taking place as the crank passes the top
and starts to descend on the expansion stroke.
FIG. 38. — Order of events in the four-stroke cycle.
25. The Mechanism of Four-stroke Engines. — In addition to the four
principal parts previously mentioned, there are a number of other small
parts which we will now discuss. First, we must have two valves located
in the upper end of the cylinder, one for the purpose of letting in the
fresh mixture of gas and air, and the other for the purpose of letting out
the burned gases. Each of these valves opens once in a cycle, that is,
once in two revolutions. In this engine (Figs. 34 to 37) the valves are
shown in the T-head arrangement, the inlet valve being on the left and
the exhaust valve on the right. These valves are of a form called poppet
valves. They are mushroom shaped, with beveled edges which fit into a
beveled seat. The valves are held shut by springs on the outside, which
pull on the valve stems and hold them tightly against the seat, so that
ENGINES 29
gases can not leak in or out, except when one of the valves is opened.
To operate the valves, there are two push rods, one for each valve.
These push rods receive their motion from the cams. On the lower ends
of these rods are rollers, and these roll on cams on the cam shaft inside of
the crank case. These cams have each a hump or projection on about
one-fourth of their circumference. When one of these strikes the roller
it raises it up, and this motion is transmitted through the push rod to the
valve. After the projection of the cam has passed under the roller, the
valve spring will close the valve and force the push rod back to the
original position.
Since the valves on an engine each work but once in two revolu-
tions, the engine must be arranged so that the cams come around only
once in two revolutions. To do this, the general arrangement is to
put a small gear on the crank shaft and have this drive another gear,
twice as large, on the cam shaft. In this way the cam shaft will run
at just half the speed of the crank shaft. These gears are called half-
time gears.
26. Valve Timing and Setting. — The exhaust valve of an engine opens
on an average of about 45° before the end of the stroke, in order that the
pressure may be reduced to atmospheric by the end of the stroke so there
will be no back pressure during the exhaust stroke. At the end of the
exhaust stroke, the exhaust valve should remain open while the crank is
passing the center so that any pressure remaining in the cylinder may have
time to be reduced to atmospheric.
The inlet valve very seldom opens before the exhaust closes. Most
manufacturers do not open the inlet until the exhaust closes, for fear
of back-firing, although there is little danger of this except with slow-
burning mixtures. The inlet valve opens, on an average, 10° late (after
center). At the end of the suction stroke there is still a slight vacuum
in the cylinder and the inlet is kept open for a few degrees past center to
allow this to fill up and get the greatest possible quantity of gas into the
cylinder. On an average, the inlet valve closes about 35° late, de-
pending on the piston speed of the engine.
In studying the valve setting of an engine, the first step, of course, is
to observe the timing of the engine as it stands. To do this we must turn
the engine by hand. By inserting a thin sheet of tissue paper between
a valve stem and its push rod, we can tell when the valve opens and
closes by noticing when the paper is gripped in opening the valve and
when it is released in closing. The corresponding crank positions should
be noted. We can then see whether it is possible to do anything to
improve the valve setting. Valve cams are made for a certain valve
setting and will give a certain angle of opening. This may become
altered in several ways. Any excessive lost motion in the valve motion
30 THE GASOLINE AUTOMOBILE
will result in a valve's opening too late and closing too early. Wear on
the cam will have the same effect. If a cam shaft has been removed and
replaced, the timing gears may be put together wrong. This would ad-
vance or retard the whole series of events and can readily be found out
when the timing is observed.
The clearance or lost motion in the valve mechanism between the
cam and the valve stem should be about 3^4 in. or less. In order to
keep the valves quiet on their engines, some makers use a clearance of the
thickness of ordinary writing paper, or about %0oo in- If the clear-
ance or lost motion is too great, it will cause the valve to open late and
close early, and will also cause the cam to strike the roller a hard blow
with the middle of its face, instead of catching it gradually at the beginning
of the incline. It will also reduce the valve opening and possibly choke
the engine.
In a four-stroke engine the cam shaft revolves once for each two
revolutions of the crank shaft. Consequently, a valve opening of 180°
will be represented by but 90° on the cam, and, for any given crank
angle through which the valve is to be open, the corresponding cam angle
will be but one-half the given crank angle. If an exhaust valve is to
open 45° before the beginning of the exhaust stroke and close 10° after
the end of the stroke, the total crank angle will be
180° + 45° + 10° = 235°
235°
The corresponding cam angle = ~ = 117^°. By "cam angle"
we mean the angle on the cam, from the point where it starts to open the
valve to the point where the valve is seated again. An inlet valve that
is to open 10° late and close 30° late, would have a total crank angle of
180° - 10° + 30° = 200°
200°
The corresponding cam angle = — ^— = 100°.
27. Valves. — The prevailing type of valve is what is called the poppet
or mushroom type — poppet, from its operation, and mushroom, from its
shape. The exhaust valve must be opened by a cam because it must
be opened against a pressure of 40 to 60 Ib. in the cylinder and held
open while gases are forced out through it. The inlet valve may be
opened by a cam or we may use a light spring and depend on the suction
to open it. The suction type is, of course, cheaper to build, but it re-
duces the capacity of the engine so that for the same power there is no
saving. Consequently we find automatic inlets as a rule only on the
small farm engines that are built to sell at a low price. To open an
automatic valve, there must be a difference in 'pressure on the two sides
ENGINES
31
of the valve equal to the tension of the valve spring. This tension may
be reduced or increased by the weight of the valve, if vertical, and opening
respectively downward or upward. For' high-speed engines an auto-
matic valve is particularly unsuited, since a heavy spring must be used
to insure quick closing at high speed.
Poppet valves usually have 45° beveled seats as shown in Fig. 39,
though occasionally flat valves are seen which rest on flat seats. The
valves must be large enough to let the gases in and out of the cylinders
freely. If they are too small they will cut down the power of the engine
by not permitting it to get a full charge. The valves usually measure
from one-third to one-half of the cylinder diameter. Valve diameters are
usually measured by the opening in the valve seat (see dimension marked
d in Fig. 39). The diameters of the inlet and exhaust pipes should at
least equal this valve diameter and should be larger if possible.
Fia. 39.
FIG. 40.
FIG. 41.
The valve lift should, when possible, be sufficient to give the gases as
large a passage between the valve and seat as they have through the
opening d, Fig. 39. For a flat valve seat this would require a lift of one-
fourth of the valve diameter. With a beveled seat, the gases pass
through an opening in the shape of a conical ring having a width of
passage equal to hf, Fig. 39. To have the necessary passage area, the
lift h of the valve should be about three-tenths of the diameter. In
most stationary engines this lift can be given the valve, but in high-speed
engines it would be too noisy. This lift would then cause pounding and
wear on the cams; it would require very stiff springs to make the valves
follow the cams in closing and would be very hard on the valve seats and
stems. For automobile engines the valves are made as large as possible
and the lift is limited to from % Q to ^ in.
The best materials for valve heads are cast-iron, nickel-steel, and
tungsten-steel. Cast-iron is very cheap, easily worked, and stands
corrosion well. It is weak, however, and therefore requires a heavier
weight than other materials and this is especially objectionable for high-
speed engines. The nickel-steel is strong, non-corrosive, and has a
very low coefficient of heat expansion. Hence it does not warp so readily
32
THE GASOLINE AUTOMOBILE
as other metals It is rather expensive and when used is generally
electrically welded to a carbon-steel valve stem. The tungsten-steel is
very hard and will stand high temperatures without pitting. Cast-iron
valve heads can be screwed on a steel stem as in Fig. 40, the stem being
riveted to prevent loosening. Figure 41 shows a common European form
FIG. 42.— T-head.
FIG. 43.— L-head.
FIG. 44.— I-head.
FIG. 45.— L-and-I head.
for valves which is being rapidly adopted here. The curvature under-
neath gives the gases a smooth passage without any of the whirling eddies
that occur under the ordinary flat valve.
Any valve needs regrinding into its seat occasionally with oil and
emery or ground glass. Exhaust valves require this more often than
inlet valves, as they become warped and pitted by the hot gases. After
ENGINES
33
a valve is ground in, the push rods should be readjusted, as the grinding
will lower the valve and reduce the clearance in the valve motion.
28. Valve Arrangements. — The possible arrangements of the valves
in the cylinder are numerous. Figure 42 shows the T-head arrangement
used in many of the large automobiles. This arrangement permits of a
large valve and a low lift, and therefore makes a very quiet engine. Fig-
ure 43 shows the L-type with both valves on one side. This is the most
common type. It requires only one cam shaft and has a very simple,
INNER SLEE
FIG. 46. — Section of Silent Knight engine.
direct-acting valve mechanism. It does not have as much cooling surface
to the combustion chamber and is, therefore, more economical in the use
of fuel than the T-head. Figure 44 shows the valve-in-the-head arrange-
ment. This is sometimes called the I-head arrangement. It is especially
popular for racing cars because it gives a short, quick passage into the
combustion chamber and gives a simple, compact combustion chamber
with a minimum loss of heat to the cooling water. Figure 45 shows an
arrangement used on the Reo car that is a combination of the L-type
and the valve-in-the-head type, the intake valve being in the top and
34 THE GASOLINE AUTOMOBILE
operated by a rocker arm while the exhaust is on the side and is operated
by a direct push rod. Both valves are operated from one cam shaft.
29. The Knight Engine.— The Knight engine is built on the principle
of the four-stroke cycle, but the usual poppet valves have been replaced
by two concentric sleeves sliding up and down between the piston and
cylinder walls. Certain slots in these sleeves register with one another
at proper intervals, producing direct openings into the combustion
chamber from the exhaust and inlet ports. The construction of the
Steams-Knight motor is illustrated in Fig. 46 which shows the general
arrangement of the parts and their nomenclature.
FIG. 47. — Action of sleeves in Knight engine.
It will be noted that two sleeves are independently operated by small
connecting rods working from an eccentric or small crank shaft running
lengthwise of the motor. This eccentric shaft is positively driven by
a silent chain at one-half the speed of the crank shaft. The eccentric
pin operating the inner sleeve is given a certain lead or advance over
that operating the outer sleeve. This lead, together with the rota-
tion of the eccentric shaft at half the crank-shaft speed, produces the
valve action illustrated in Fig. 47, which shows the relative positions of
the piston, sleeves, and cylinder ports at various points in the rotation of
the crank shaft.
30. The Rotary Valve.— The rotary valve as used in the Speedwell
car consists of two cylindrical shafts in the head of the motor, one for ex-
ENGINES
35
haust and one for the inlet. These shafts are slotted and when rotating
register with ports in the cylinder walls, thus opening passageways for
intake and exhaust gases. The rotary movement of the valves is con-
tinuous in one direction, the valves being driven by a silent chain from
the crank shaft. Figure 48 illustrates the different positions of the
rotary valves at the beginning of each of the four strokes. The arrows
inside show the direction of rotation of the valves and the arrows out-
side indicate the direction of the fresh gas going in and the exhaust gas
passing out of the cylinder.
31. Two-stroke Engines. — Two-stroke engines as a class are not so
flexible as the four-stroke engines under the varying speeds and loads
encountered in automobile service. Consequently they have not been
used to any great extent in motor cars, although a few satisfactory cars
have been built with them.
INDUCTION
COMPRESSION EXPLOSION
FIG. 48. — Speedwell rotary valve engine.
EXHAUST
Since the piston of a four-stroke engine receives an impulse or ex-
plosion only once in two revolutions, considerable effort has been ex-
pended in trying to develop an automobile engine that would give an
explosion in each cylinder every revolution and yet would operate as
satisfactorily and economically as the four-stroke engine. An impulse
every revolution would make a more powerful engine than one of the
same size which received an impulse only once in two revolutions and it
would also make the flow of power more continuous for the same number
of cylinders.
The Two-port Engine. — Most of the two-stroke engines in use are very
much like those shown in Figs. 49 to 52. In appearance, these engines
are much simpler than the four-stroke engine, but are not necessarily
any simpler in operation. They do not have any valves opening into the
combustion chamber, such as are found in the four-stroke engine. The
exhaust gases leave the cylinder through a port in the cylinder wall, which
is uncovered by the piston at the end of the expansion stroke, as shown in
Fig. 50. At the same time, a fresh charge is blown into the cylinder through
36 THE GASOLINE AUTOMOBILE
a similar port on the other side. The top of the piston has a deflector
which turns the incoming charge up into the clearance space. The
charge then strikes the cylinder head, which turns it down on the other
side toward the exhaust port, thus driving the dead gases out ahead of
it. The piston then comes back, shuts off both these openings and
compresses the fresh charge into the clearance space as shown in Fig.
49. It is then ignited in the usual manner by a spark plug screwed into
the cylinder head. This gives the piston an impulse every revolution.
The engines of Figs. 49 to 52 have each crank enclosed all around
and they use this case or chamber as a sort of a pump to supply fresh gas
to the cylinder. When the piston goes up, the space inside the crank case
is increased, and when it comes down the space is reduced, thus main-
taining a breathing action inside the crank case. In Fig. 49 the piston
Spark Plug
Exhaust Port
Transfer Port
/ Check Valve (Open) jig
Carburetor
/Deflector
Transfer
Check Valve (Closed)
FIG. 49. FIG. 50
FIGS. 49 AND 50. — Two-port, two-stroke engine.
is shown traveling toward the top. This motion causes a suction in
the crank case and causes air to enter through the carburetor. As the
air passes through the carburetor it becomes saturated with gasoline and
then passes through the check valve into the crank case. When the
piston gets to the top, the suction ceases and the check valve is closed
by its spring. Meanwhile, an explosive mixture has been compressed
above the piston and at the top of the stroke is ignited by a spark. This
produces an explosion or rise in pressure above the piston, just as in the
four-stroke cycle and this drives the piston down on its working stroke.
As the piston comes down, it compresses the fresh gases in the crank
case into a smaller volume and thus raises their pressure. Meanwhile,
as the piston nears the bottom of its stroke, it uncovers the exhaust port
and the pressure in the cylinder causes a large part of the burned gases
ENGINES
37
to shoot out through this port. An instant later the piston uncovers a
transfer port on the other side and is now in the position shown in Fig.
50. This transfer port is connected into the crank case and therefore allows
the gases from the crank case to blow over into the cylinder as shown
in Fig. 50.
The piston head is so shaped as to form a deflector, which turns
the fresh charge toward the cylinder head so that it can not blow out
the exhaust port. The piston then returns, cuts off these ports, and
compresses this charge, meanwhile drawing another charge into the
crank case. This engine is called a two-port type, because there are only
two ports in the cylinder walls to be operated by the piston.
The Three-port Engine. — The only difference between this type and
the preceding one is in the method of admitting the gases into the crank
Spark Plug
Met Port
Deflector
•Transfer Port
Exhaust
Carburetor \-,
FIG. 51. FIG. 52.
FIGS. 51 AND 52. — Three-port, two-stroke engine.
case. Instead of using a check-valve, the admission of the gases' to the
crank case is controlled by the piston, which uncovers a third port in the
cylinder walls as it nears the top of the compression stroke. As will be
seen in Fig. 51, the carburetor is on the other side of the engine, placed
just below the exhaust pipe. As the piston rises, it creates a suction in
the crank case, but there is no way for any gas to get in until the piston
reaches the top of its stroke. As the piston uncovers this third port, the
air enters with a rush through the carburetor, picks up the gasoline on its
way through, and enters the crank case. The piston then descends, cuts
off the third port, compresses the gases in the crank case, as in Fig. 52,
and then blows them over into the cylinder as before.
Against the two-stroke engine we have the facts found from ex-
perience that they 'are not as economical in the use of fuel and are more
38 THE GASOLINE AUTOMOBILE
uncertain in their action than the four-stroke engine. Since the fresh
charge is depended on to blow out the exhaust gases, it is evident that
some of the incoming charge is liable to pass out through the exhaust port.
Gases mix very quickly and it is not possible to keep the dead and fresh
gases separate, and yet drive the dead gases out and fill the cylinder com-
pletely with fresh gases. If a full charge enters through the transfer
port, some of it will be lost through the exhaust port without its being
utilized. By skillfully proportioning the two ports and the shape of the
deflector to the size and speed of the engine, it is possible to largely pre-
vent the waste of fuel through the exhaust port.
A two-stroke engine does not get as full a charge of gas as does a four-
stroke engine and, consequently, will not be twice as powerful. The
horse power of a two-stroke engine is usually about 1% to 1^ times that
of a four-stroke engine of the same size and speed.
The small two-stroke engines shown in Figs. 49 to 52 sometimes cause
trouble from back-firing or exploding in the crank case. This is caused
by the mixture in the crank case becoming ignited and exploding before
it goes over into the cylinder. This wastes the energy of the gas and fills
the crank case with dead gases, so that the engine will frequently come to
a stop. Back-firing is caused by the mixture in the cylinder being still in
flames when the piston uncovers the transfer port. The flame shoots
through this port into the crank case and fires the mixture there. It has
been found by experience that mixtures weak in gas are the ones which
burn slowly and therefore cause back-firing. Consequently, the cure for
crank-case explosions is to give the engine more fuel.
Any leaks into the crank case are very serious in either of these
types. With the slow speed used -in starting an engine by hand, a very
small leak may admit air enough to satisfy the suction in the crank case
and thus prevent any gas from being drawn in or, at any rate, it may so
weaken the mixture as to make it non-explosive.
This brief statement of some of the difficulties of the two-stroke engine
will show some of the things that must be overcome in order to make this
type of motor generally applicable to automobile service.
32. The Flywheel. — The purpose of the flywheel is to keep the engine
running from one explosion to the next, and to make the engine run
smoothly. If an engine did not have a flywheel, it would run in a very
jerky manner, if it ran at all, and it is more probable that the explosion
would simply drive the piston to the other end of the stroke and that it
would stop there. Any one knows that the heavier a moving object is
and the faster it is going, the harder it is to stop it. The flywheel on an
engine is quite heavy and the result is that, once started, it will keep the
engine going for some time. A gas-engine flywheel must not only be
heavy enough to keep it going from one explosion to the next, but must
ENGINES 39
keep it going without allowing the speed of the engine to drop down too
much between explosions.
33. Ignition. — In order to cause the explosions within the cylinder,
some means must be provided for lighting the charge of gas. This is
usually done by causing an electric spark to pass between two points
within the cylinder. The spark sets fire to the mixture and the explosion
follows.
There are two general methods of electric ignition. One of these is
called the make-and-break system because it requires some moving
parts inside the cylinder to make an electric circuit, and then break it
quickly so that a spark will occur inside the cylinder. The other system
is called the jump-spark system. This is the system used in automo-
biles. There are no moving parts which have to pass through the cylinder
wall in this system. The spark coil or magneto makes a current powerful
enough to jump between two fixed points inside the cylinder. The
complete details of these systems of ignition will be taken up in a later
chapter.
34. Clearance and Compression. — It was discovered by some of the
early inventors of gas engines that compressing a gaseous mixture causes
it to give a much more powerful explosion. Consequently, all gas engines
draw in a full cylinder charge of gas and air, and then compress this back
into a space left at the upper or rear end of the cylinder. This space,
which is left for the gas to occupy when the piston is at the top end of its
stroke, is called the clearance space or combustion chamber. The amount
of this clearance space in relation to the whole cylinder volume determines
just how much the gas is compressed. It has been found from experience
that different kinds of gases require different amounts of compression and,
therefore, the clearance space is made different for different fuels. The
clearance is generally spoken of as being a certain per cent, of the piston
displacement, varying from 24 to 30 per cent, for automobile engines.
35. Piston Displacement. — This refers to the space swept through by
the piston in going from one end of the stroke to the other. It is given
this name because, as the piston moves through its stroke, it will either
draw in or force out that volume of air or gas. The piston displacement
is calculated by multiplying the length of stroke by the area of a circle
whose diameter is the inside diameter of the cylinder. For example, a
3j^-in by 5-in. engine (this means 33^ in. inside cylinder diameter and
5 in. stroke) would have a piston displacement as follows:
The area of a 3^-in. circle is 0.7854 X 3>^ X 3>£ = 9.621 sq. in.
The piston displacement is 5 times this, or 48.105 cu. in.
The clearance of such an engine would be from 24 to 30 per cent,
of this. If we suppose that it is 25 per cent., then the actual space which
must be left for the clearance will be 48.105 X 0.25 = 12.026 cu. in.
40 THE GASOLINE AUTOMOBILE
36. Cylinder Cooling.— When an explosion occurs inside the cylinder
of an engine, the gases on the inside reach a temperature somewhere
around 3000°. The walls of the cylinder are, of course, exposed to this
high heat and would very quickly get red hot if we did not have some way
of keeping them cool. The polished surface upon which the piston slides
would be very quickly spoiled. The most common way of keeping the
cylinder cool is by the use of water, and the arrangement for this is shown
in the engines illustrated in this chapter. Surrounding the cylinder is a
jacket with a space between for the cooling water. By keeping a supply
of water passing through this space, the cylinder can be kept cool enough
for the operation of the engine. The cylinder head is also cast with a
double wall, especially around the valves, so that these parts will also be
kept cool. The cooling fluid used is generally water, although sometimes
special anti-freezing solutions are used where there is danger of the
engine freezing. Water should not be allowed to remain in the jacket of
an engine over night if there is danger of a frost, as the freezing of the
water will crack the cylinder. When the supply of water is limited, as
in an automobile, the water is cooled in a radiator or system of pipes, and
used over again. The water is kept in circulation by a pump or by the
thermo-syphon system and the hot water is cooled by the air passing over
the radiator.
37. The Muffler. — When the exhaust valve of an engine opens at the
end of the expansion stroke the pressure of the gas inside the cylinder is
FIG. 53.— Typical muffler.
still about 50 or 60 Ib. per square inch. The valve must open and let
this pressure out before the piston starts back, or else the back pressure
will tend to stop the engine. The valve is opened quickly, and the high
pressure, being suddenly released into the exhaust pipe, causes the
sharp sound which we hear when an engine exhausts. This sound is not
the sound of the explosion, as is commonly supposed. The real ex-
plosion takes place a little before this sound and can be heard only as a
dull thump inside the cylinder. The explosion occurs at the beginning
of the working stroke, while the sound that we hear in the exhaust comes
at the end of the stroke.
In order to prevent this sudden exhaust from causing too great a
ENGINES 41
noise it is customary to have a muffler. A muffler is generally a chamber
in the exhaust pipe which receives the exhaust gases from the engine and
expands them gradually into the outside air, thus preventing a loud
noise. A common arrangement of an automobile muffler is shown in
Fig. 53.
38. Horse Power of Engines. — The horse power of an engine is
the measure of the rate at which it can do work. One horse power is
a rate of 33,000 ft.-lb. a minute. There are two ways of measuring
engine power. We can determine the power developed by the ex-
plosions in the cylinder, in which case we have what is called the indi-
cated horse power (i.hp.} ; or we can attach a brake to the flywheel and
measure the power which the engine actually delivers. This is called
the brake horse power (b.hp.). Engines are usually rated by their brake
horse power because that is what they are actually capable of delivering.
The brake horse power of an automobile engine will usually be from 70
to 85 per cent, of its indicated horse power, the loss being that consumed
in the engine mechanism.
There are a number of quick rules for estimating the power of engines
according to their cylinder dimensions and the speed. Those most
used for four-stroke engines are given below. The simplest of these and
the one most used is known as the S. A. E. formula or Society of Auto-
mobile Engineers formula.
Authority Formula
S. A. E. 1 D2N
= hp.
Royal Auto Club 2.5
Brit. Inst. of Auto Engrs. 0.45 (D + L) (D - 1.18) = hp.
D27 7? AT
E. W. Roberts -- = hp.
D = diameter of cylinder in inches. R = revolutions per minute of
crank shaft.
L = length of stroke in inches. N = number of cylinders.
Derivation of the S. A. E. Horse Power Formula. — The indicated horse
power of a single-cylinder, four-stroke engine is equal to the mean ef-
fective pressure, P, acting throughout the working stroke, times the area
of the piston, A, in square inches, times one-quarter times the piston speed,
S, divided by 33,000, thus:
PAS
~ 33,000 X 4
Multiplying this by the number of cylinders, N, gives the indicated
horse power for an engine of the given number of cylinders, and further
multiplying by the mechanical efficiency of the engine, E, gives the
brake horse power.
6
42 THE GASOLINE AUTOMOBILE
Therefore, the complete equation for brake horse power reads:
PASNE
b.hp. - 33^000 x 4
The S. A. E. formula assumes that all motor car engines would de-
liver or should deliver their rated power at a piston speed of 1000 ft.
per minute, that the mean effective pressure in such engine cylinders
would average 90 Ib. per square inch, and that the mechanical efficiency
would average 75 per cent.
Substituting these values in the above brake horse power equation,
and substituting for A its equivalent, 0.7854Z)2, the equation reads:
90 X 0.7854P2 X 1000 X N X 0.75
33,000 X 4
and combining the numerical values it reduces to:
To make it simpler, the denominator has been changed to 2.5 without
materially changing the results.
The formula can be simplified, however, for ordinary use by consider-
ing the number of cylinders; thus for the usual four-, six-, and eight-
cylinder engines it becomes:
1.6 D2 = hp. for all four-cylinder motors.
2.4 D2 = hp. for all six-cylinder motors.
3.2 D2 = hp. for all eight-cylinder motors.
4.8 D2 = hp. for all twelve-cylinder motors.
The S. A. E. formula comes very close to the actual horse power
delivered by most automobile engines at the piston speed of 1000 ft.
per minute. However, at the present time, most of the engines will
deliver the maximum power at speeds higher than this, usually around
1500 ft. per minute. As a result, the power which the engines are capable
of delivering is greater than that given by the S. A. E. formula. The
formula will serve, however, as a means of comparing engines on a uniform
basis.
CHAPTER III
POWER-PLANT GROUPS AND TRANSMISSION SYSTEMS
39. Single- and Multi-cylinder Engines. — The first automobile power
plant consisted of a one-cylinder engine which gave power impulses at
regular intervals of time for the propulsion of the car. Naturally it
operated very jerkily and with considerable noise, due to the size of the
cylinder and the time between impulses. These facts led to the adoption
-Two Revolutions-
Compreaalon
1 Cylinder
2 Cylinders
4 Cylinders
6 Cylinders
8 Cylinders
FIG. 54. — Power diagrams.
of the two-, four-, and six-cylinder engines, and quite recently the eight- and
twelve-cylinder engines have come into use as automobile power plants.
In Fig. 54 can be seen one of the distinct advantages of the multi-
cylinder engine for motor car purposes. The length of the diagram
represents two revolutions of the engine crank shaft. The curved line
7 43
44 THE GASOLINE AUTOMOBILE
acefg represents the variations in the power from a single cylinder. The
line bh represents uniform power requirement of the car. When the
power curve goes above bh the engine accelerates and the surplus power
is thus stored in the flywheel; when the curve goes below bh the flywheel
gives up power and the engine slows down.
As the number of cylinders increases, the impulses increase in fre-
quency, the average power is greater, and above four cylinders there is
no period during which some cylinder is not delivering power. This
means that in a six- or eight-cylinder car, there is no time at which the
flywheel must supply all the power required by the car.
The multi-cylinder engine, therefore, furnishes a practically continu-
ous flow of power to the car with little vibration. The increase in the
number of cylinders has a tendency to reduce the size of each cylinder
and this fact combined with the steady operation of the engine, makes the
modern automobile engine a very smooth-running, quiet, power-plant
unit.
40. Power Plant and Transmission Arrangements. — Figure 55 shows
the arrangement of the Studebaker power plant and transmission system.
The engine is placed in the front of the frame, being supported at four
points. The clutch, which is of the cone type, is built inside the flywheel,
and permits the engine to be disengaged from the transmission system.
The propeller shaft, which transmits the power from the engine to rear
wheels, is connected to the clutch by means of a universal joint which
permits the shaft to receive power and to deliver it to the rear axle.
The change-gear set or transmission is placed on the rear axle just in
front of the differential housing which carries the differential gear. The
change-gear set permits the relative speed of the engine and car to be
changed according to conditions. The chassis diagram indicates the
location of the other important parts. Notice the three-quarter elliptic
rear springs.
The chassis of the Mitchell "Eight" is shown in Fig. 56. The engine
in this case is supported at only three points, one at the front and two at
the rear. The clutch is of the cone type operating in connection with the
flywheel. It will also be noticed that the change-gear set is placed at the
front of the propeller shaft, which then goes directly to the final drive
on the rear axle. There is a single universal joint, which is between the
clutch and gear set.
The Hollier " Eight" chassis is shown in Fig. 57. Here we see the
application of the well-known "unit power plant" in which engine,
clutch, and change gears are built into one single unit. This arrangement
permits the use of only one universal joint between power plant and rear
axle. Notice the cantilever type of rear springs.
In the chassis of the Ford Model T, Fig. 58, use is also made of the
POWER-PLANT GROUPS
45
~~Un/ verso/
,' Joints
FIG. 55.— Chassis of Studebaker "Six,
46
THE GASOLINE AUTOMOBILE
FIG, 56,— Chassis of Mitchell "Eight
POWER-PLANT GROUPS
47
Un/f
FIG. 57.— Chassis of Hollier "Eight."
4g THE GASOLINE AUTOMOBILE
"unit power plant" with three-point support. The engine, clutch, and
change gears are built together in a single unit and are supported on the
frame at only three points. The connection between power plant
and rear axle is made by the use of only one universal joint. As will be
seen later, this car is equipped with a "planetary" transmission which is
built on a principle entirely different from the usual clutches and change-
gear sets. The entire rear of the car is supported by an inverted semi-
Tic. 58.— Chassis of Ford Model T.
elliptic spring extending over the rear axle. A similar but lighter
spring is used in front.
The sectional view of the Lyons-Knight four-cylinder car in Fig. 59
shows very clearly the arrangement of the engine and the transmission
groups. The engine is of the Knight type and delivers its power through
a plate clutch and through the universal joints and propeller shaft to the
POWER-PLANT GROUPS
49
50
THE GASOLINE AUTOMOBILE
change gear set built on the rear axle. The final drive from shaft to axle
is of the worm type which will be discussed later in the chapter. The
clutch control pedal and the change gear control lever are outlined very
clearly.
41. Modern Automobile Power Plants. — The automobile power plant
includes the engine and all accessories necessary for the production of
power. The transmission system includes the mechanism necessary for
taking this power furnished by the power plant and transmitting it to the
rear wheels.
In most cases, the power plant includes the engine and its component
parts such as carburetor, ignition devices, cooling system, etc. and the
Hot water outlet-,^
Air heater
exhaust
Co/a1 water
Cone -~
c/utch
'ater supply
to pump
Water pump
Magneto
FIG. 60. — Four-cylinder Wisconsin engine.
transmission system includes the clutch, change gears, universal joints,
differential, and rear axle. When the unit power plant is used, it includes
in addition to the engine and its essential component parts, the clutch and
the change gears.
Four-cylinder Power PZante.— Figure 60 illustrates a typical four-
cylinder automobile engine with the essential parts indicated. The view
shown is the exhaust side of the motor, it having the T-head valve arrange-
ment. The cylinders are cast in pairs, two cylinders being in each unit,
he water jackets are cast integral with the cylinders. The water con-
itions at the top and bottom of each casting are indicated. The clutch,
POWER-PLANT GROUPS
51
•Sfar~f/'n(j motot — generator-
FIG. 61.— The 1914 Cadillac engine.
52
THE GASOLINE AUTOMOBILE
FIG. 62. — Studebaker "Four" engine.
FIG. 63.— Section of Buda engine.
POWER-PLANT GROUPS
III 1 1
54
THE GASOLINE AUTOMOBILE
one member of which is machined in the engine flywheel, is of the cone
type, this being the customary method of applying the cone clutch to the
engine.
The engine of the 1914 Cadillac is illustrated from both sides in Fig. 61
s of the L-head type, having both intake and exhaust manifolds on
POWER-PLANT GROUPS 55
the right side. The most prominent feature of this engine is that the
cylinders are cast singly with copper water jackets fastened securely
around the castings. The single-cylinder castings necessitate a longer
engine than if cast in pairs or en bloc, but they also make the renewal
expense less if a single cylinder is damaged.
Figure 62 is a right-side view of the Studebaker "Four" engine,
showing the en bloc cylinder construction, in which all cylinders are cast
in one piece. This permits the engine to be much shorter than when
cast in any other way. The structure is also more rigid, and can be
made considerably lighter than when cast singly.
wafer oaf/ef
Removable, cylinder \
head \ ft j. • connection
one clutch Cy/inc/ers cast en- bloc
FIG. 66.— Power plant of MitcheU "Six."
The sectional view of a Buda Model T engine in Fig. 63 shows very
clearly the internal construction of an engine. This engine is of the
L-head type with only one cam shaft. The crank shaft is of the con-
ventional three-bearing type, i.e., with a bearing at each end and one
at the center.
The Ford unit power plant is shown in section in Fig. 64 with all
parts fully designated. The magneto, change gears and clutching ar-
rangement are of considerable interest and will be discussed under the
proper headings. As will be remembered, this power plant has three-
point support.
56
THE GASOLINE AUTOMOBILE
Six-cylinder Power Plants. — The Jeffrey six-cylinder power plant
is shown in section in Fig. 65. The cylinders are cast in pairs, thus
permitting the use of a four-bearing crank shaft. In the pair of cylinders
at the left, the section is taken through the valves so as to show the cams,
push rods, springs, and valves. The center pair is sectioned through
the center of the cylinders so as to show the pistons, pins, and con-
necting rods. The valve arrangement is of the L-head type.
The engine of the "Mitchell Six of '16," Fig. 66, has the six cylinders
cast "en bloc," which gives a very compact and rigid construction of
pleasing appearance. The cylinder head can be removed in one piece for
the purpose of cylinder and valve examination.
The Franklin motor, Fig. 67, represents a very interesting and
unique design, having overhead valves and air-cooling. The cylinders
are cast singly and each is air cooled by a system of cast ribs and air
cooling, doing away with the water jackets around the cylinders. The
FIG. 67.— The Franklin air-cooled engine.
air is drawn downward around the cylinder ribs by the suction of the
flywheel fan.
42. Constructional Features of Four- and Six-cylinder Engines.— The
essential differences of construction in the various four- and six-cylinder
engines, outside of the methods of cylinder construction and valve arrange-
ment, consist in the construction and arrangement of the cam and crank
shafts. Figure 68 is a conventional four-cylinder crank shaft, shown with
connecting rods and pistons attached. There are three main bearings,
as indicated. The connecting rod bearings are all in the same plane, bear-
ings Nos. 1 and 4 being just 180° from Nos. 2 and 3. This means that
the Nos. 1 and 4 pistons are in the same position in the cylinders at the
same time. Likewise Nos. 2 and 3 are in the same position. If No. 1
piston is on the compression stroke, No. 4 must necessarily be on the
exhaust stroke and Nos. 2 and 3 on the suction and explosion strokes,
POWER-PLANT GROUPS
57
The order of firing in a four-cylinder engine must be in the order 1, 3,
4, 2 or 1, 2, 4, 3.
The five-bearing crank shaft for a four-cylinder engine has main bear-
ings between all the cranks. Figure 69 shows the five-bearing crank shaft
FIG. 68. — Three-bearing, four-cylinder crank shaft.
in place on the 1914 Cadillac four-cylinder engine. This type of crank-
shaft construction is especially adapted to an engine with individually
cast cylinders.
Chain drive for-
ajneto & oump
FIG. 69. — Five-bearing, four-cylinder crank shaft in position.
The crank shaft for a six-cylinder engine is arranged as shown in Fig.
70. Cranks 1 and 6, 2 and 5, 3 and 4 are in pairs and are spaced 120°
58
THE GASOLINE AUTOMOBILE
apart. The pistons in the paired cylinders are always in the same relative
positions in the cylinders. The firing order of the cylinders is usually 1,
5, 3, 6, 2, 4 or 1, 2, 3, 6, 5,4. This crank has four main bearings. The
PISTON RINS
PISTON
XNn SHAFT SEAR'NS
CONNECTING WOO BEARHMS
•OH- DIPPER
CRANK SHAFT
CRANK
SHAFT GBA«
/ 'STARTINS
INUT
FIG. 70. — Four-bearing, six-cylinder crank shaft.
shaft shown in Fig. 71 has only three main bearings. The arrangement
of the cranks is the same as in the previous case.
Matn bearings
FIG. 71.— Three-bearing, six-cylinder crank shaft.
In Figs. 72 and 73 are illustrated the two general methods of cam shaft
construction. Figure 72 is a one-piece cam shaft, the cams and shaft
Fia. 72. — One-piece cam shaft.
being made of one solid bar of steel. This is the more common method of
construction. The assembled cam shaft, Fig. 73, on which the individual
cams are pinned or keyed is used at present in very few cases. The ob-
POWER-PLANT GROUPS
59
jection to this type of shaft is that the cams may become loose on the
shaft and give considerable trouble. For an L-head engine, a single cam
shaft on one side of the engine carries both inlet and exhaust cams. For
FIG. 73.— Assembled cam shaft.
FIG. 74. — Cadillac eight-cylinder V-type engine.
a T-head engine, however, one cam shaft carries the inlet cams on one side
of the engine and another shaft carries the exhaust cams on the other side
60 THE GASOLINE AUTOMOBILE
The cam shafts are driven at one-half crank shaft speed. The drive
can either be by a silent chain, such as shown for the 1914 Cadillac in Fig.
69, by spur gears such as in the Ford Model T shown in Fig. 64, or by
helical gears such as shown in Figs. 72 and 73.
43. Eight- and Twelve-cylinder Power Plants. — In the four-cylinder
engine, there is a power stroke every one-half revolution, but during a
small interval at the end of each power stroke no power is being delivered
by the engine. This means short periods in the operation of the engine in
which the flywheel must supply all the power. In the six-cylinder engine,
FIG. 75. — Sectional view of Cadillac eight-cylinder engine.
there is a power stroke every one-third revolution and, as a result, there is
an overlapping and a more continuous flow of power (see Fig. 54). The
impulses come oftener and, consequently, reduce the vibration. The
same effect is carried further in the eight-cylinder engine which gives a
power stroke every one-fourth revolution. The parts are considerably
lighter and this aids in reducing the vibration. Most of the eight-cylinder
engines are built in the V-type and this method of construction adds to the
smoothness of operation.
Cadillac Eight-cylinder Engine.— Figure 74 is a front-end view of the
Cadillac eight-cylinder engine. The cylinders are arranged in blocks of
POWER-PLANT GROUPS
61
four each, placed in a V-shape at an angle of 90°. A cross section of two
opposite cylinders is shown in Fig. 75. The engine is of the L-head type
with the valves on the inside of the V. One cam shaft placed directly
above the crank shaft operates all of the sixteen valves by means of the
rockers as shown. Eight cams serve to operate the sixteen valves, as
FIG. 76. — A pair of Cadillac connecting rods.
FIG. 77.
one cam operates a valve in each group. The cam shaft is carried by five
bearings and has a silent chain drive as shown in Fig. 74.
The crank shaft is like a conventional four-cylinder shaft with three
main bearings. There are only four crank pins, two connecting rods, one
from each group, bearing on the same crank. One of the rods, Fig. 76,
is forked, while the other is perfectly straight, fitting in between the fork.
The split bearing shown at the right fits directly over the pin. The forked
62
THE GASOLINE AUTOMOBILE
rod fits over this bearing and is pinned to it, so that the rod and bearing
work together. The other rod fits in the center surface of the bearing and
LJ
FIG. 78.— Top view of Mitchell "Eight" engine.
FIG. 79. — Front view of Mitchell "Eight" engine.
runs on it. The arrangements permit the length of the crank shaft to be
no greater than in a four-cylinder engine.
POWER-PLANT GROUPS
63
The order of firing of the eight cylinders alternates from one side to
the other. If the cylinders be numbered as shown in Fig. 77 the firing
order is as follows: 1-L, 2-R, 3-L, 1-R, 4-L, 3-R, 2-L, and 4-R. The horse
power rating of the Cadillac Eight is 31.25 according to the S. A. E.
formula. On dynamometer test, however, it has developed 70 hp. at a
speed of 2400 r.p.m.
Mitchell Eight. — The Mitchell Eight is constructed on the same gen-
eral principle as the type previously mentioned. The cylinder groups are
placed in a V of 90°. The valves are placed on the inside of the V and
FIG. 80.— Engine of Packard "Twin Six."
are operated by means of eight cams on a single cam shaft mounted above
the crank shaft. The cylinders are slightly staggered and two connecting
rods are mounted side by side on each crank instead of using the forked
construction.
The engine is rated at 48 hp. The cylinders are 3-in. bore by 5^-
in. stroke. The top and front-end views are shown in Figs. 78 and 79.
The Packard Twelve-cylinder Engine. — The twelve-cylinder unit power
plant of the Packard car is shown in Fig. 80. The twelve cylinders are
cast in two blocks of six, arranged in V-type with an included angle of 60°.
The cylinders have a 3-in. bore and a 5-in. stroke with L-head valve ar-
rangement. The left block of cylinders is set forward of the right set by
64
THE GASOLINE AUTOMOBILE
\Y± in. in order to permit the lower end of the connecting rods of opposite
cylinders to be placed side by side on the same crank pin. In addition,
this arrangement permits the use of a separate cam for each valve,
making 24 cams on the cam shaft. The single cam shaft is placed directly
above the crank shaft. The crank shaft is of the usual six-cylinder type
supported by three main bearings.
Advantages Claimed for Eight- and Twelve-cylinder Motors.— The chief
advantages claimed by the eight- and twelve-cylinder motors are smooth
running, lack of vibration, rapidity of pick-up, and wide range of activity
Flywheel
Clutch teathej
Clutch cone
Clutch release
r/ny — — - — \
Transmission \
cose-
Clutch qear--*\
^
Clutch brake
Clufch thrust bearing-
C/ufch spring
Crank shaft--
FIG. 81. — Buick cone clutch.
on high gear. It is possible with either of these types to run almost
entirely on high speed under all conditions.
44. Clutches. — The gasoline engine must be set in motion before it
will take up its cycle and generate power. This fact prevents it from being
started under load and, consequently, means must be provided for de-
taching the engine from the rest of the mechanism for starting before the
load is thrown on. This mechanism for detaching the engine from the
remaining part of the power and transmission system is called the
"clutch." There are in use at the present time two general types of
clutches, the cone type and the disc type.
The Cone Clutch. — Figure 81 illustrates the cone clutch as used in the
Buick car. It consists of a leather-faced aluminum cone which is held
POWER-PLANT GROUPS 65
tightly against the inside of the tapered rim of the flywheel by four springs
carried on a spider. The aluminum cone is mounted on a steel sleeve
which can slide back and forth on the clutch gear shaft to disengage or
engage the cone with the flywheel. A grooved ring at the rear end of the
sleeve connects the clutch to the clutch pedal. A small brake, attached
to the transmission case, serves to keep the clutch from spinning after it
is released. Four small spring plungers, located under the leather, force
it out at these points and prevent grabbing when the clutch is let in.
In operation, pressure on the clutch pedal is transmitted by a con-
necting link and clutch release shaft to the yoke operating on the ball-
bearing release ring, which pulls the clutch back out of engagement with
the flywheel. The small brake now holds the clutch stationary, while
the clutch spider and springs continue to turn with the flywheel until the
clutch is again engaged. When in full engagement, the clutch and fly-
wheel turn as a unit, transmitting the power through the gear set to the
rear axle.
Multiple Disc Clutches. — The multiple disc clutch is built in two types
— the dry plate and wet plate. Figure 82 is a sectional view of the dry
plate type of clutch as used on the Hudson. It consists of a series of
alternate driving and driven discs. The driving discs receive their power
from the flywheel by four studs, one of which shows in the cut. These
discs are steel stampings.
The driven discs are also steel stampings but are somewhat thicker
and have holes into which cork inserts are pressed. The driven discs
drive the inner drum by means of a series of grooves or slots.
The driven and driving discs are pressed together by the clutch spring
shown. When it is desired to release the clutch, the foot pedal compresses
the clutch spring and the plates separate, permitting the driving members
to run independently of the driven members. As -in all clutches, the
power is transmitted entirely through a frictional contact. The cork
inserts are used because they are soft and at the same time have a great
adhesive property, even if they become soaked with oil. The advantage
of this type of clutching arrangement is that a large frictional surface can
be obtained with a comparatively small clutch diameter. In the cone
type this diameter must necessarily be large in order to get the necessary
friction surface on the one surface in contact. In letting in the plain cone
type of clutch, there is also the possibility of a more sudden engagement
than with the multiple disc type. This has been overcome by the use of
the springs under the leather, as shown in Fig. 81.
The wet plate clutch is constructed on the same general principles as
the dry plate clutch, the essential difference being that it runs in a bath of
oil. When the clutch is released, an oil film covers the entire surface of
the plates and, when the clutch is thrown in, this film of oil is gradually
66 THE GASOLINE AUTOMOBILE
squeezed out, permitting a very easy and gradual engagement. In the
winter time, the oil may be unusually heavy and this prevents a quick
engagement. This can be overcome by thinning the clutch oil with
kerosene.
FIG. 82. — Hudson dry plate clutch.
45. Change Gear Sets. — The change gear set is for the purpose of
permitting different speed ratios between the engine and the car. When
starting, the engine must run comparatively fast and the car slow.
When the car gets under way, the relative speed of car and engine must be
changed in order to get efficient operation.
Figure 83 is the gear set used on the Jeffrey car. The right shaft is
driven by the clutch; attached to this shaft is the drive gear which at
all time drives the lay-shaft drive gear fastened to the lay-shaft. The lay
shaft in addition carries four fixed gears as shown. The main drive
shaft has one end bearing rotating within the main drive gear. Con-
sequently the drive gear and main shaft can run independently of each
other. The main shaft carries two sets of sliding gears, the names and
purposes of which are indicated. These two sets are operated by two
POWER-PLANT GROUPS
67
shifter yokes which lead to the gear control lever in the car. This gear
set provides four forward speeds and a reverse speed. This type is
known as the "selective sliding gear set," because, as the name in-
dicates, any one of the speeds can be selected at will, in contrast to the
"progressive sliding gear set" in which the speeds must be taken in
succession.
Figure 84 illustrates the gear positions for the various speeds obtained
in the Studebaker three-speed-and-reverse gear set. The white arrows
indicate the gears through which the power is transmitted for the different
speeds.
SHIFTS R BOO C»P f ROOT
IDtNGGCAR )**
FIG. 83. — Jeffrey gear set.
46. Planetary Gearing. — This type of combined clutch and change
gears, such as used on the Ford Model T, is especially adapted to light
cars in which two forward speeds are sufficient. The gears are not shifted
into or out of mesh for the different speeds, as in the sliding gear set, but
they are always in mesh, as shown in Fig. 85. On high gear, the entire
mechanism is clamped solidly together by the clutch and revolves as a
single mass with the flywheel. The clutch is of the multiple disc type,
running in oil. The flywheel has three studs, each of which carries three
gears of different sizes fastened together to form what is called a "triple
gear." These triple gears mesh with three gears of different sizes in line
with the engine shaft. The inner one, next to the flywheel face, is fast-
68
THE GASOLINE AUTOMOBILE
TE
' REVERSE IDLER GEAR L"
'"---PINION SHAFT C
FIRST SPEED
OR" LOW"
OR INTERMEDIATE
THIRD OR
"HIGH" SPEED
REVERSE
FIG. 84. — Positions of gears in Studebaker three-speed-and-reverse gear set.
POWER-PLANT GROUPS
69
ened to the drive shaft which delivers the power through to the rear axle.
The other two central gears float on the drive shaft and are connected
to the two drums nearest to the engine. Surrounding these drums, but
not shown in the figure, are brake bands which can be tightened by foot
pedals. These can be seen in Fig. 64. If the slow-speed drum is gripped,
the second of the three central gears will be held stationary. This makes
the triple gears rotate on their studs as the flywheel revolves. In doing
this, they drive the inner central gear, or the driving gear, slowly forward,
FIG. 85. — Ford planetary transmission.
due to the differences in the sizes of the gears. If the middle drum is
gripped instead, by pushing on the reverse pedal, the larger of the central
gears is held. This makes the triple gears revolve again on their studs as
the flywheel revolves, but since this reverse gear is larger than the drive
gear, the motion of these triple gears will turn the drive gear slowly back-
ward. For high speed, the entire mechanism is gripped solidly together
so that it revolves at engine speed. The third drum is used for a service
brake.
47. Universal Joints and Drive Shaft. — The use of one or more univer-
sal joints between the power plant and the rear axle is necessary, as can
be seen in Fig. 59, in order to provide for the lower position of the rear
axle and also to allow for the spring action between the axle and the frame
which carries the power plant. The universal joint permits this to be
done with very little loss of power. Figure 86 shows the propeller shaft
or drive shaft of the Jeffrey car with its universal joints. A square block
in the center of the universal joint fits between the jaws of two forks, one
of which is connected to the power plant and the other is attached to the
70
THE GASOLINE AUTOMOBILE
end of the drive shaft. The flexible connection of these forks to the block
permits the drive shaft to oscillate freely with the rear axle and yet con-
tinue to receive and transmit power.
ftANOE YOKE
COMPLETE UNIVERSAL JOINT
LOCIT RIN8 D
FIG. 86. — Jeffrey propeller shaft and universal joints.
48. Final Drive. — The final drive to the rear axle is accomplished by
means of bevel, spiral-bevel, or worm gearing. The direction of the power
transmission must be changed through a right angle at this point.
Figure 87 shows the bevel gear final drive as used on the Jeffrey car. Both
the bevel pinion and the differential housing which carries the driving gear
or ring gear are carried by ball bearings. The action of the bevel gears
FIG. 87.— Jeffrey final drive.
produces a side thrust, caused by the inclination of the faces of the teeth,
tending to separate the gears. This makes it necessary that the bearings
of these gears be capable of resisting this thrust. Either ball bearings or
tapered roller bearings are employed. If the straight rollers are used for
bearings, special thrust bearings must be provided.
"Figure 88 shows a spiral-bevel gear drive with the Timken tapered
POWER-PLANT GROUPS
71
roller bearings, as used on the Cadillac car. The chief claims for the
spiral-bevel drive are that the spiral teeth give a more continuous driving
action between the teeth and overcome any possible inaccuracies in the
teeth or any tendencies to wear irregularly; also that they overcome the
thrust, to a more or less extent, by producing a counteracting pull.
Fig. 89 shows the worm drive to the rear axle. This has the worm
placed above the gear. The worm drive in Fig. 59 shows one with the
worm placed underneath. The worm
drive is very quiet running, but requires
careful lubrication because of the con-
stant sliding action between the teeth of
the worm and gear. One of the two
gears should run in an oil bath. The
worm drive is especially popular in
FIG. 88.— Cadillac spiral-bevel
drive.
FIG. 89. — Worm drive used on Jeffrey
"Chesterfield Six."
heavy truck service where there is a large reduction in speed. The
worm is generally made of steel and the gear of bronze to keep down the
friction.
49. Types of Live Rear Axles. — The dead rear axle was illustrated and
explained in Chap. I. The live axle is used on practically all makes of
pleasure cars, with only one or two exceptions. Live rear axles are clas-
sified according to their methods of construction as simple, semi-floating,
three-quarter floating, and full floating.
Simple Live Axle. — The simple live axle used on the Ford Model T is
shown in Fig. 90. This type of rear axle performs two functions in that
it carries the entire weight of the rear of the car in addition to transmitting
the power. The rear wheel is keyed to the axle as shown. The weight
72
THE GASOLINE AUTOMOBILE
is carried by roller bearings directly on the live axles both at the wheel and
differential ends.
Semi- floating Axle. — Figure 91 is of the semi-floating type and shows
ICJOiif
the essential difference between a simple and semi-floating live axle. In
the semi-floating axle the inner bearings are carried on an extension of the
Qtial.case, thus relieving this end of the live axle of considerable
POWER-PLANT GROUPS 73
stress. The wheel as in the other case is keyed to the axle. The con-
struction at the outer end of the semi-floating axle is the same as in the
simple axle. In either of these types the weight of the car produces a
bending stress in the axle.
Three-quarter Floating Axle. — Figure 92 shows the change in this type
of construction from the semi-floating type. The weight is carried by the
bearings on the housing and directly in line with the spokes, thus re-
lieving the axle of all bearing stresses. The wheel is keyed onto the shaft.
FIG. 91. — Semi-floating rear axle.
Although in the three-quarter type the live axle is relieved of all weight,
nevertheless the bending strains due to a possible side movement of the
wheel, or the distortion due to a bent housing are still thrown on the axle
due to the fact that the wheel is keyed onto the axle. Also, in this type,
if the live axle breaks, the wheel can come off and let the car drop. This
is prevented only by the full-floating construction.
Full-floating Rear Axles. — Figure 93 shows the full-floating construc-
tion as used on the Buick car. The wheel is carried on a double ball or
roller bearing on the axle housing, in such a way as to retain the wheel
on the housing regardless of what may happen to the live axle. In this
construction, the live shaft receives only the torsional strains of driving
the car, all other loads being taken by the axle housing. The live shaft
may be removed and replaced without disturbing either the wheel or the
74
THE GASOLINE AUTOMOBILE
differential. The inner ends of the axle shafts are grooved and slide into
corresponding grooves in the differential gears. The entire drive shaft
on either side may be removed by merely removing a hub cap and sliding
the shaft out. In the form shown in Fig. 93, the shaft is keyed into the
FIG. 92. — Three-quarter floating axle construction.
GIVING YOKE
ADJUSTM£MJ
- PROPELLER SHAFT HOUSING
BRACE fiODS
PROPELLER SHAFT
SRAKC. OPERATING
SHAFTS
BRAKE DRUM """
CREASE PLUC
DRIVtMC FLANGE
HUB BEAR/NO
FIG. 93.— Buick full-floating rear axle.
hub cap. In another form, the outer end of the shaft has a toothed clutch
which fits into corresponding recesses in the outer face of the hub. This
permits a certain amount of play and relieves the shaft from any distor-
tion if the axle housing becomes bent.
CHAPTER IV
FUELS AND CARBURETT1NG SYSTEMS
One of the most important operations in a gas engine is that of getting
an explosive mixture inside of the engine cylinder at the proper time. This
explosive mixture is formed by the thorough mixing of air and a gas
formed by the evaporation of a volatile liquid fuel, usually gasoline.
50. Hydrocarbon Oils. — Most of the liquid fuels are known as
"hydrocarbon" oils, because they are made from crude mineral oil con-
taining as its principal parts, hydrogen and carbon. One of the hydro-
carbon fuels, viz., alcohol, is not of mineral derivation, but is made by
the distillation of vegetable matter.
The crude oil or petroleum from which the hydrocarbon fuels are
made is found in natural deposits several hundred feet below the earth's
surface. In some places it has to be pumped out, while in others it is
forced out by natural gas pressure. Most of the crude oil found in the
United States comes from Pennsylvania, Ohio, Illinois, Kansas, Texas,
Oklahoma and California. These crude oils are of two general types,
that coming from Texas, Oklahoma, and California having what is known
as an "asphalt" base, and that from Pennsylvania and Ohio having a
"paraffin" base. Crude oil having an "asphalt" base is a heavy dark
liquid, which when boiled, leaves a black tarry residue. If the crude oil
has a "paraffin" base, it is much lighter in weight and color and, when
boiled, leaves a residue from which is made the white paraffin or wax with
which everyone is familiar.
Formerly, gasoline made from crude oil with a paraffin base was sup-
posed to be of a higher grade than the other, but with the modern proc-
esses of refining, the gasoline from the two kinds of crude oil gives equally
good results.
51. Fractional Distillation of Petroleum. — The crude oil is heated in
large retorts or "stills," provided with accurate temperature recording
devices. When the temperature has reached about 100°F. a vapor be-
gins to rise from the oil. This vapor is collected from the top of the retort
and condensed in cooling coils, from which the liquid is collected in vessels.
As the temperature in the retort rises, the vapor becomes heavier and,
when condensed, gives the heavier and less volatile liquid fuels. The
following table gives, approximately, the products of this method of
distillation :
75
76 THE GASOLINE AUTOMOBILE
Distilling at IOO°F to I25°F
Hiqhly Volatile oils -qasoline,
benzine, naphtha, ICTtolB%.
Distilling at 125* F to 350*F.
Kerosene and light lubricat-
ing oils; 65 to
Distilling at over 35O'F
Heavy oils, paraffin wax,
etc, 15 to 20%
FIG. 94. — Approximate fractions in the distillation of crude oil.
Temperature in the
retort
Kind of oil after condensing the vapor
Percentage
100°F to 125°F.
125°F. to 350°F.
Over 350°F.
Highly volatile oils (gasoline, benzine and
naphtha).
Kerosene and light lubricating oils.
Heavy oils, paraffin wax and residue.
10 to 15 per cent.
65 to 75 per cent.
15 to 20 per cent.
It will be noticed that there is from three to five times as much kerosene
and light lubricating oils produced under this method as there is gasoline.
This accounts for the late scarcity of gasoline and the more volatile fuels,
and the overproduction of kerosene and the less volatile fuels, which can
not be used successfully in an automobile engine.
In order to utilize a part of these less volatile fuels, the Standard Oil
Co. has developed the Burton process by which these less volatile fuels
are redistilled under pressure. This process gives an additional amount
of volatile fuel very much like the gasoline obtained from the first distilla-
tion. This process has increased the percentage of gasoline from the
crude oil to such an extent that the market is now liberally supplied.
The Bureau of Mines has recently developed the new Rittman process
for increasing the amount of gasoline produced from the crude oil. It
is a continuous process, in contrast to the "batch" Burton process. The
two processes are somewhat similar in character and have as their end an
increase in the production of gasoline from the crude oil.
62. Principles of Vaporization. — Before an explosive mixture can be
formed, the liquid fuel must first be turned into a gas and then mixed
with the proper amount of air to burn it. As we know, it requires heat to
FUELS AND CARBURETTING SYSTEMS 77
change water into steam or vapor. If the water is out in the open, it will
evaporate rapidly, or boil, at a temperature of 212°. Likewise, in order
to change a liquid fuel into a gas or vapor, it is necessary that heat be
added to it, but the temperature at which this heat is added is different for
different fuels. For instance, gasoline will evaporate under the usual
atmospheric pressure and temperature and will, in some cases, evaporate
at a temperature close to 0° F. This can be tested by exposing a pan
of gasoline to the air. In a short time the liquid will have evaporated.
That heat has been absorbed can be verified by feeling of the dish before
it is filled and again after evaporation has been taking place.
Kerosene and alcohol, on the other hand, will not evaporate until heat
is added from an external source at a higher temperature, the same as is
done when steam is made from water. This explains the difficulty of
evaporating these fuels for use in a gas engine.
From the above considerations, the general principles of vaporization
are formulated :
1. The heavier a liquid and the higher its boiling point, the harder
it will vaporize; for example, kerosene as compared with gasoline.
2. A liquid fuel will vaporize easier and faster under a suction, or re-
duction of pressure than under pressure ; for example, gasoline is more dif-
ficult to vaporize at low than at high altitudes.
3. The closer the temperature of a liquid fuel is to its boiling point,
the easier and faster it will vaporize; for example, gasoline will vaporize
more readily in summer than in winter.
The Baume Test. — Gasoline is usually spoken of as high or low test.
By reference to the principles of vaporization, we see that the heavier
a liquid, the harder it is to evaporate. This principle explains the reason
for the use of the Baume" test. A hydrometer, such as shown in Fig.
95 is graduated in degrees, the numbers reading from the bottom up.
These degrees have nothing to do with thermometer degrees, but are
named after Baume, who originated the idea. When the hydrometer is
placed in a quantity of gasoline, it will sink to a depth corresponding to
the density of the liquid. It will sink deeper in a light gasoline than in a
heavier one. The deeper the hydrometer sinks, the higher the scale read-
ing will be. This scale, reading from 45 to 95° Baume", indicates in an
indirect way the ease and rapidity with which the gasoline will evapo-
rate. It is not a direct and absolute test unless the nature and the
boiling points of the crude oil from which the gasoline has been distilled
are known. For most purposes, however, it merely serves as a guide as to
the way the gasoline will act in service.
Gasoline. — The commercial gasoline of today has a Baume" test of
from 50 to 65°, the better or high test being in the neighborhood of 65°
and the poorer, or low test, in the neighborhood of 50°. For summer
78
THE GASOLINE AUTOMOBILE
use, the low test or heavier gasoline can be used very .well because it
will evaporate with comparative ease at the usual summer temperatures,
but in the winter the high test or light gasoline is to be preferred because
it will evaporate more easily at the low temperatures. More work can
be obtained from a gallon of the heavier or low test gasoline, providing it is
completely vaporized, but it is very difficult to vaporize at low tempera-
tures and consequently makes starting very hard in cold weather.
Kerosene Gasoline
FIG. 95. — Baum6 hydrometer in kerosene and gasoline.
Occasionally, a low grade, impure gasoline is sold which lacks sufficient
refinement and purification, the sulphur and other impurities not having
been eliminated. The use of this may result in carbon deposits in the
cylinders. A gasoline that readily carbonizes should be avoided and a
higher grade used.
Kerosene and Alcohol. — To use either of these fuels requires the heating
of the fuel or the air, or both, in order to secure vaporization. At pres-
ent, the price of alcohol is too high to warrant giving any serious con-
sideration to its use. Several more or less successful devices have been
tried for using kerosene, but the varying speeds and loads of the auto-
FUELS AND CARBURETTING SYSTEMS 79
mobile engine make the problem of controlling the heat very difficult.
The reductions in the price of gasoline in the past 2 or 3 years and the
very promising prospects for a greater increase in the supply and corre-
sponding reduction in the price, make it unlikely that any great develop-
ment in the use of kerosene will take place. Consequently, the discussion
to follow will deal only with gasoline and its vaporization.
53. Heating Value of Fuels. — The heating value, or the amount of
heat energy contained in a liquid fuel, is given in British thermal units
per pound; a British thermal unit, or a B.t.u., being the quantity of
heat energy required to raise the temperature of 1 Ib. of water 1° on the
Fahrenheit scale. The following table gives the heating values of the
common fuels:
Gasoline 18,000 to 19,500 B.t.u. per pound.
Kerosene about 20,000 B.t.u. per pound,
grain about 10,000 B.t.u. per pound.
Alcohol ^ wQod about 7)5(X) B t u per pound
Inasmuch as the heavier fuel contains more pounds per gallon, and as
gasoline and kerosene are sold by the gallon, a gallon of heavy or low test
gasoline or of kerosene contains more energy and gives more power than a
gallon of light, or high test gasoline.
54. Gasoline Gas and Air Mixtures. — It is necessary when the gaso-
line is vaporized that it be mixed with the proper amount of air to form
an explosive mixture. If too little air is furnished, there will not be enough
oxygen to burn the carbon and hydrogen in the fuel and the fuel will be
wasted, as will be indicated by black smoke coming from the exhaust.
If too much air is furnished, the mixture is weak in fuel, giving a very slow
combustion. This results in lost power. A weak mixture, or an excess of
air, is indicated by back-firing through the carburetor.
A definite mixture of gasoline gas and air is necessary for the efficient
operation of a gasoline engine. The function of the carburetor is to take
the gasoline, vaporize it, and furnish the proper mixture of gas and air to
the cylinders under all conditions of temperature, speed, load, power and
varying atmospheric conditions.
55. Principles of Carburetor Construction. — Most of the modern
types of carburetors are of the spray or nozzle type, in which a jet of gaso-
line is sprayed into a current of air to form an explosive mixture. Figure
96 illustrates an elementary spray carburetor. The gasoline supply tank
is placed below the carburetor and the gasoline is pumped up through the
supply pipe. The overflow pipe maintains the level of the liquid at a
constant height. The standpipe T is connected with the supply chamber
C by means of the connection N and the flow is regulated by the needle
valve S. The gasoline level in the standpipe T is always the same.
The flange B is fastened onto the intake passage of the engine. The sue-
80
THE GASOLINE AUTOMOBILE
tion of the piston draws air through the opening A upward past the stand-
pipe, and at the same time draws a spray of gasoline from T. The but-
terfly valve D is for the purpose of regulating the suction upon the stand-
pipe T when starting the engine; when running, the valve D should be
wide open. The mixture is changed by regulating the needle valve 8.
This type of carburetor can be used only on constant speed engines, the
reason for which we will see later. Figure 97 shows another elementary
type of carburetor which illustrates the application of two modern ideas.
In this case, the gasoline supply is maintained at a constant level by
means of a hollow metal or a cork float operating a ball valve. The
Fro. 96.
FIG. 97.
arrangement requires the gasoline supply tank to be placed above the
carburetor or that some other means be provided for supplying gasoline
under pressure. It will also be noticed that the passage surrounding the
standpipe or spray nozzle is contracted, giving the inside surface a convex
shape. This is the application of the well known Venturi tube principle.
By contracting the section near the opening of the nozzle the velocity of
the incoming air and consequently the suction at that point are increased,
making it much easier for the gasoline to be taken up and greatly facili-
tating the starting of an engine when the suction is low.
This type of carburetor could be used on constant speed engines only.
If a carburetor such as shown in Figs. 96 or 97 was put on a variable speed
engine and the proper adjustment made by means of the needle valve so
that the mixture proportions were correct at low speed, and the engine
should then be speeded up, we would discover black smoke coining from
the exhaust, indicating an excess of gasoline over the air supplied. This is
due to the fact that under the increased suction due to the higher speeds
of the piston, the air drawn in past the standpipe expands and increases
in volume and velocity faster than it increases in weight; while the gasoline
drawn from the nozzle, being a liquid, increases in weight just as its
velocity and volume are increased. This means that under an increased
suction too much gasoline is supplied for the amount of air drawn in.
FUELS AND CARBURETTING SYSTEMS 81
In order to keep the mixture of the proper proportions at all speeds of the
engine, it is necessary to have an auxiliary air entrance, such as indicated
at X in Fig. 98, to admit an additional amount of air at the higher engine
speeds. This entrance is usually in the form of a valve controlled by a
spring, the tension on which can be changed to control the air admission.
For low speed adjustments the gasoline needle valve is to be used, and for
high speed adjustments the auxiliary air valve is to be adjusted. That is,
when the engine is running comparatively slowly, the air is taken in
through the ordinary air opening A shown below the valve in Fig. 98.
FIG. 98. FIG. 99.
FIGS. 98 AND 99. — Sections of typical variable speed carburetors.
The mixture is then proportioned by means of the needle valve NV.
When the engine speeds up, and the suction is increased, the auxiliary air
valve S in Fig. 98 comes into action and opens. If it is found that the
mixture at high speeds is too rich, that is if there is too much fuel for the
air furnished, it indicates that the tension on the valve spring is too great,
which prevents sufficient air from entering. By reducing the tension, the
valve opens wider, letting in sufficient air to keep the mixture uniform.
If the mixture is too weak at high speeds, the spring tension is too weak.
It should be tightened so as to permit less air to enter and to increase the
suction on the gasoline.
The following general description applies to Fig. 98.
G = gasoline feed from tank.
FV = float valve controlling flow of gasoline to carburetor.
F = float, the height of which is regulated by the level of gasoline in the float
chamber. The float controls the float valve FV.
NV = gasoline needle valve for regulating the amount of gasoline furnished to the
air in the mixing chamber.
N = gasoline nozzle.
X = auxiliary air valve, to admit additional air at the high speeds.
S = spring for X.
A = primary air opening, which supplies all air at low speeds.
T = throttle valve for regulating supply of mixture from carburetor to cylinder.
P = primer for depressing float and flooding carburetor to insure rich mixture
when starting.
82
THE GASOLINE AUTOMOBILE
Figure 99 shows another carburetor, in which the auxiliary air is ad-
mitted through ports X controlled by steel balls B.
Some of the modern types of carburetors are water-jacketed, taking
the hot water from the cooling system, in order to heat the carburetor
and assist the vaporization. Another method of assisting the vapori-
zation, and one almost necessary when the low grade gasoline of today
is considered, is that of heating the air which goes into the carburetor.
This is usually done by taking it through a jacket surrounding the ex-
haust pipe. Figure 100 shows such a device.
FIG. 100. — Hot-air connection used with Master carburetor.
Another scheme used in several of the carburetors built for high
powered, high speed machines is the double-jet, which makes it easier
for the engine to draw the desired amounts of gasoline and air when it
becomes necessary for the engine to carry heavy loads at high speed.
Several of these are illustrated in the following articles, which describe
some of the leading carburetors now in use.
FIG. 101.— Schebler Model L carburetor.
56. Schebler Model L Carburetor.— The Model L carburetor, Figs.
101 and 102, is of the lift-needle type and is so designed that the amount
of fuel entering the motor is controlled by means of a raised needle work-
ing automatically with the throttle. The flow of gasoline can be adjusted
FUELS AND CARBURETTING SYSTEMS
83
for closed, intermediate, or open throttle positions, each adjustment being
independent and not affecting either of the others. This carburetor
has an automatic air valve, shown at the left in Fig. 102. At high speeds
or heavy loads, the suction raises this valve and admits an extra supply of
air. The opening of the throttle for high speed or a heavy pull raises
the needle and increases the supply of gasoline to correspond with the
increased air supply.
The Model L can be furnished with a bend for connecting or taking
warm air from around the exhaust manifold into the initial air opening at
the base of the carburetor, by means of a hot air drum and tubing.
FIG. 102. — Section of Shebler Model L carburetor.
This carburetor is also manufactured with a dash-control to the air
valve spring, this being operated by a lever which is controlled by a
switch on the dashboard or steering post of the car. This control is
shown on Fig. 102.
Rules for Adjusting Schebler Model L. — The carburetor should be
connected to the intake manifold so that it is located below the bottom of
the gasoline tank a sufficient distance to be filled by gravity under all
running conditions. Where pressure feed is used, it is unnecessary to
locate the carburetor below the gasoline tank; also, when pressure is used,
it is never advisable to carry over 2 Ib.
Before adjusting the carburetor, make sure that the ignition is prop-
erly timed; that there is a good hot spark at each plug; that the valves are
properly timed and seated; that all connections between the intake valves
and the carburetor are tight; and that there are no air leaks of any kind
84 THE GASOLINE AUTOMOBILE
in these connections. The carburetor should be adjusted to the motor
under normal running temperature, and not to a cold motor.
In adjusting the carburetor, first make the adjustments on the auxili-
ary air valve so that the air valve seats lightly but firmly. The lever on
the dash control should be set in the center of the dashboard adjuster,
and with this setting of the lever, the tension on the air valve should be
light, yet firm. Close the needle valve by turning the adjustment screw
to the right. until it stops. Do not use any pressure on this adjustment
screw after it meets with resistance. Then turn it to the left about four
or five turns and prime or flush the carburetor by pulling up the priming
lever and holding it up for about 5 seconds; Next, open the throttle
about one-third and start the motor; then close the throttle slightly,
retard the spark, and adjust the throttle lever screw and the needle
valve adjusting screw, so that the motor runs at the desired speed and
hits on all cylinders.
After getting a good adjustment with the motor running idle do not
touch the needle valve adjustment again, but make your intermediate
and high speed adjustments on the dials. Adjust the pointer on the first
dial about half way between figure 1 and figure 3. Advance the spark
and open the throttle so that the roller on the track running below the
dials is in line with the first dial. If the motor back-fires with the throttle
in this position and the spark advanced, turn the indicator a little more
toward figure 3; if the mixture is too rich, turn the indicator back, or
toward figure 1, until you are satisfied that the motor is running properly
with the throttle in this position, or at intermediate speed. Now open the
throttle wide and make the adjustment on the second dial for high speed
in the same manner as you have made the adjustments for intermediate
speed on the first dial.
67. Schebler Model R.— The Model R Schebler carburetor, Fig. 103,
is designed for use on both four- and six-cylinder motors. It is a single-jet
raised-needle type of carburetor, automatic in action. The air valve
controls the lift of the needle so as to automatically proportion the amount
of gasoline and air at all speeds.
The Model R carburetor is designed with an adjustment for low speed.
As the speed of the motor increases, the air valve opens, raising the gaso-
line needle and thus automatically increasing the amount of fuel. This
carburetor has but two adjustments, the low speed needle adjustment,
which is made by turning the air valve cap, and an adjustment on the air
valve spring for changing its tension.
The Model R carburetor has an eccentric which acts on the needle
valve, intended to be. operated either from the steering column or from the
dash, and insures easy starting, as, by raising the needle from the seat,
an extremely rich mixture is furnished for starting and for heating up the
FUELS AND CARBURETTING SYSTEMS
85
motor in cold weather. A choke valve in the air bend is also furnished.
The dashboard control or steering column control must be used with this
carburetor; it cannot be operated satisfactorily without them.
Rules for Adjusting Model R Carburetor. — When the carburetor is
installed, see that lever B is attached to the steering column control or
dash control so that when boss D of lever B is against stop C the lever on
the steering column control or dash control will register "Lean" or "Air."
This is the proper running position for lever B.
FIG. 103.— Schebler Model R carburetor.
To adjust the carburetor turn the air valve cap A clockwise or to the
right until it stops, then turn it to the left or anti-clockwise one complete
turn.
To start the engine, open the throttle about one-eighth or one-quarter
way. When the engine is started, let it run till it is warmed, then turn the
air valve cap A to the left or anti-clockwise until the engine hits perfectly.
Advance the spark three-quarters of the way on the quadrant; then if the
engine back-fires on quick acceleration, turn the adjusting screw F up
(which increases the tension on the air valve spring) until acceleration is
satisfactory.
Turning the air valve cap A to the right or clockwise lifts the needle E
out of the nozzle and enriches the mixture; turning to the left or anti-
clockwise lowers the needle into the nozzle and makes the mixture lean.
86 THE GASOLINE AUTOMOBILE
When the motor is cold or the car has been standing, move the steer-
ing column or dash control lever toward "Gas" or "Rich." This oper-
ates the lever B and lifts the needle E out of the gasoline nozzle and makes
a rich mixture for starting. As the motor warms up, move the control
lever gradually back toward "Air" or "Lean" to obtain best running
conditions, until the motor has reached normal temperature. When
this temperature is reached, the control lever should be at " Air " or "Lean."
For best economy, the slow speed adjustment should be made as lean as
possible.
68. The Holley Model H Carburetor. — This carburetor is shown
in Fig. 104. Before the fuel enters the float chamber, it passes a strainer
FIG. 104.— Holley Model H carburetor.
disc A which removes all foreign matter that might interfere with the
seating of the float valve B under the action of the cork float, and its
lever C.
Fuel passes from the float chamber D into the nozzle well E through a
passage F drilled through the wall separating them. From the nozzle
well, the fuel enters the cup G through the hole H, and rises past the needle
valve, /, to a level which partially submerges the lower end of a small
tube, J, having its outlet K at the edge of the throttle disc.
FUELS AND CARBURETTING SYSTEMS 87
Cranking the engine, with the throttle kept nearly closed, causes a
very energetic flow of air through the tube J and its calibrated throttling
plug K. But with the engine at rest the lower end of this tube is partially
submerged in fuel. Therefore, the act of cranking automatically primes
the motor. With the motor turning over under its own power, flow
through the tube J takes place at very high velocity, thus causing the fuel
entering the tube with the air to be thoroughly atomized upon its exit
from the small opening at the throttle edge. This tube is called the
"low speed tube" because, for starting and idle running, all of the fuel
and most of the air in the working mixture are taken through it.
As the throttle opening is increased beyond that needed for idling of
the motor, a considerable volume of air is drawn down around the outside
of the strangling tube L and then upward through this tube. In its pas-
sage into the strangling tube, the air is made to assume an annular, con-
verging stream form, so that the point in its flow at which it attains its
highest velocity is in the immediate neighborhood of the upper end of
the ' ' standpipe " M . The velocity of air flow being highest at the upper or
outlet end of the standpipe, the pressure in the air stream is lowest at the
same point. For this reason, there is a pressure difference between the
top and bottom openings of the pipe M , thus causing air to flow through
it from bottom to top, the air passing downward through the openings
N in the bridge supporting the standpipe and then up through the
standpipe.
With a very small throttle opening, the action through the standpipe
keeps the nozzle cup thoroughly cleaned out, the fuel being carried directly
from the needle opening into the entrance of the standpipe. . To secure
the best vaporization of the fuel, the passage through the standpipe is
given an aspirator form, which further increases the velocity of flow
through it, and insures the greatest possible mixing of the fuel with the
air. A further point is that the vaporized discharge of the standpipe
enters the main air stream at the point at which the latter attains its
highest velocity and lowest pressure.
There is but one adjustment, that of the needle valve /. The effect
of a change in its setting is manifest over the whole range of the motor.
59. Holley Model G. — This carburetor, Fig. 105, is a special design
for Ford cars.
The operation of this carburetor is the same as the regular Model H
already illustrated and described. The chief differences are the structural
ones giving a horizontal instead of a vertical outlet, a needle valve con-
trolled from above instead of from below, and a simplification of design to
secure compactness.
Fuet enters the carburetor by way of a float mechanism in which a
hinged ring float, in rising with the fuel, raises the float valve into contact
88 THE GASOLINE AUTOMOBILE
with its seat. This seat is removable and the float valve is provided with
a tip of hard material.
From the float chamber the gasoline passes through the ports E to
the nozzle orifice, in which is located the pointed end of the needle F.
The ports E are well above the bottom of the float chamber, so that, even
should water or other foreign matter enter the float chamber, it would
have to be present in very considerable quantity before it could interfere
with the operation of the carburetor. A drain valve D is provided for
the purpose of drawing off whatever sediment or water may accumulate
in the float chamber.
FIG. 105.— Holley Model G carburetor.
The float level is so set that the gasoline rises past the needle valve F
and sufficiently fills the cup G to submerge the lower end of the small tube
H. Drilled passages in the casting communicate the upper end of this
tube with an outlet at the edge of the throttle disc. The tube and passage
give the starting and idling actions, as described in connection with the
Holley Model H.
The strangling tube / gives the entering air stream an annular con-
verging form, in which the lowest pressure and highest velocity occur
immediately above the cup G; thus it is seen that the fuel issuing past the
needle valve F is immediately picked up by the main air stream, at the
point of the latter's highest velocity.
The lever L operates the throttle in the mixture outlet. A larger disc
with its lever S forms a spring-returned choke valve in the air intake, for
starting in extremely cold weather.
FUELS AND CARBU RETTING SYSTEMS
89
60. Stewart Model 25. — This carburetor, which is manufactured by
the Detroit Lubricator Company, involves an interesting principle of
operation.
Figure 106 gives a cross section of this carburetor and shows the posi-
tion of the air valve with engine running and air and gasoline being
admitted.
With the engine at rest and no air passing through the carburetor, the
air valve A rests on the seat B, closing the main air passage. The gasoline
rises to a height of about 1^ in. below the top of the central aspirating
FIG. 106. — Stewart Model 25 carburetor.
tube L. As soon as the engine starts to rotate, a partial vacuum is formed
above the air valve, causing it to lift from its seat and admit air, at the
same time gasoline being drawn up through the aspirating tube L. The
lower end of the air valve extends down into the gasoline and around the
metering pin P. Due to the decreasing diameter of this pin, the higher
the air valve is lifted the larger will be the opening into the tube L, and
the more gasoline will be drawn up. The upper end of the air valve meas-
ures the air, the lower end measures the gasoline; therefore, as the suction
varies, the air valve moves up or down and the volume of air and the
amount of gasoline admitted to the mixing chamber increase or decrease
in the same ratio. Most of the air passing through the carburetor goes
through the air passages as indicated by the black arrows. A -small
amount is drawn through the drilled holes HH and past the end of the
90
THE GASOLINE AUTOMOBILE
tube L. The flared end of this tube deflects the air through a small an-
nulus, thereby increasing the velocity of air at this point so as to aid in
atomizing the fuel.
The air valve is restrained from any tendency to flutter, caused by the
intermittent suction of the cylinders, by the dash pot D. Due to the
greater inertia of the gasoline and because it flows comparatively slowly
through the small opening and into the dash pot, the air valve can rise or
fall only as liquid is expelled or admitted and thus the air valve is held
steady. The Stewart carburetors have but one adjustment, which raises
or lowers the metering pin, thereby decreasing or increasing the amount of
gasoline admitted to the mixing chamber. The correct position of the
metering pin is determined with the motor running at idling speed. This
adjustment may be manipulated at the dash to compensate for extreme
changes in atmospheric temperatures and for use in starting in cold
weather.
61. Kingston Model L. — Figure 107 shows the construction of this car-
buretor. Gasoline enters the carburetor from the tank at the connection
A and is maintained at a constant level, through the agency of the float.
A pool of gasoline forms in the base of
the U-shaped mixing tube and will always
be present when the motor is not run-
ning. This aids in positive starting.
When the motor starts, this pool is
quickly lowered to the point of adjust-
ment of the needle valve and continues
to feed from this point till the motor is
stopped.
When the motor is running slowly,
the air valve B rests lightly on its seat,
allowing no air to pass through; con-
sequently all air must pass through the
low speed mixing tube C. Due to the lower end of this tube being close
to the spray nozzle and all the low speed air having to pass this point,
the atomized gasoline drawn from nozzle D becomes thoroughly mixed
with air in its upward course and is carried in this state to the motor.
When the throttle is opened slowly, the following action takes place.
The motor now requires a greater volume of mixture. The air valve B
slowly leaves its seat, permitting an extra air supply to enter and compen-
sate for the increased flow of gasoline produced by the greater suction of
the motor. In this carburetor the extra amount of gasoline for the
starting and warming up period can be obtained by opening the needle
valve .adjustment at the dash or by the use of the choke throttle E placed
in the air passage,
FIG. 107.— Kingston Model L
carburetor.
FUELS AND CARBURETTING SYSTEMS 91
When starting with a cold motor, this choke throttle can be closed by
pulling the wire forward. This cuts off nearly all the air supply and pro-
duces a very strong suction at the spray nozzle, which causes the gasoline
to jet up and be carried with the incoming rush of air to the cylinders.
A drain cock G is placed at the lowest point in the bowl and should be
opened from time to time to free the bowl of all water and foreign matter.
Rules for A djusting Kingston Model L. — Retard the spark fully. Open
the throttle about five or six notches of the quadrant on the steering post.
Loosen the needle valve binder nut on the carburetor until the needle valve
turns easily.. Turn the needle valve (with dash adjustment) until it
seats lightly. Do not force it. Adjust it away from its seat one com-
plete turn. This will be slightly more than necessary but will assist in
easy starting.
Start the motor and open or close the throttle until the motor runs at
fair speed, not too fast, and allow it to run long enough to warm up to
service conditions. Now make the final adjustment. This carburetor
has but one adjustment — the needle valve. Close the throttle until the
motor runs at the desired idling speed. This can be controlled by ad-
justing the stop screw in the throttle lever.
Adjust the needle valve toward its seat slowly until the motor begins
to lose speed, thus indicating a weak or lean mixture. Now adjust the
needle valve away from its seat very slowly until the motor attains its
best and most positive speed. This should complete the adjustment.
Close the throttle until the motor runs slowly, then open it rapidly. The
motor should respond strongly. Should the acceleration seem slightly
weak or sluggish, a slight adjustment of the needle valve may be advisable
to correct this condition. With the adjustment completed, tighten the
binder nut until the needle valve turns hard.
62. Marvel Carburetor. — The Marvel, shown in Fig. 108, is of the
double nozzle type, the second nozzle coming into action at high speeds.
At low speeds all the air is drawn through the venturi tube, where it takes
up gasoline from the primary nozzle. At high speeds after the air has
passed the choke damper, it divides, part of it going through the venturi
tube around the low speed spray nozzle, and the remainder passing to one
side and opening the auxiliary valve against the pressure of its spring.
Near the top of the auxiliary air valve is the secondary or high speed
spray nozzle.
The rush of air through the venturi tube picks up and vaporizes the
gasoline from the low speed nozzle and carries it in suspension past the
throttle and to the cylinders. When the suction at the auxiliary air valve
has increased sufficiently to open this valve and create a high velocity at
this point, gasoline is also picked up from the high speed nozzle and car-
ried to the cylinders in like manner,
10
92
THE GASOLINE AUTOMOBILE
The choke damper in the air inlet is used only for starting the motor,
by partially shutting off the air supply and forcing the motor to suck in a
rich mixture.
To the throttle is connected a hot air damper, which when open al-
lows the exhaust gas from the motor to flow through a cored passage
around the throttle, where it heats the mixture of gasoline and air. A
tube connects this passage with another which surrounds the venturi tube
and spray nozzle, and provides heat for the incoming fuel and air.
Hot air jacket
xing chamber ^
,7~hr
ottle
throttle
/ . Hot air damper
Auxiliary air valve
Auxiliary spray nozzle
~Neea'/e valve
"A"
FIG. 108. — The Marvel carburetor.
Rules for Adjusting the Marvel Carburetor. — The following rules for
adjustment are given by the manufacturers:
Start by turning the needle valve A to the right until it is completely
closed, and the air adjustment B to the left until it stops. Now give the
air adjusting screw B three complete turns to the right, and open the
needle valve A two complete turns to the left. Start the motor as usual,
using the strangler button to get a rich mixture at first. Close the
throttle until the motor runs slowly and verify the needle valve adjust-
ment A by turning it to the right a little at a time (% to % of a turn should
be sufficient) until the motor runs smoothly and evenly. At this point the
motor should be allowed to run until thoroughly warmed up.
After the motor has warmed up, turn the air valve adjusting screw B
to the left, a little at a time, until the motor begins to slow down. This
indicates that the air valve spring is too loose. Turn it back to the right
just enough to make the motor run well.
To test the adjustment, advance the spark and open the throttle
quickly. The motor should "take hold" instantly and speed up at once.
FUELS AND CARBURETTING SYSTEMS
93
If it misses or pops back in the carburetor, open needle valve A slightly by
turning to the left. Do not move the air adjusting screw B any more un-
less it appears absolutely necessary.
The best possible adjustment has been secured when the air adjust-
ment B is turned as far as possible to the left and the needle valve A is
turned as far as possible to the right, providing the motor runs smoothly
and picks up quickly when the throttle is opened.
Mixture RCGULATOfl TUBE HCU» t SCREW
•* AUXILIARY GASOUNE WELL f
t GASOUNC WELL PLUG GASKET
[PRMARV NOZZLE NEEDLE VALVE (COMPLETE)
FIG. 109. — Stromberg Model H carburetor.
If the motor runs too fast with throttle closed, turn the small set screw
in throttle stop to the left. If the motor stops when the throttle is fully
closed, turn the set screw to the right.
As the throttle opens, the hot air damper, which is connected to it by a
link, gradually closes, the greatest amount of hot air passing through the
jackets when the throttle is nearly closed. The position of the hot air
damper at any time is indicated by the slot at the end of the damper
shaft. By loosening the set screw in the damper lever, this can be set
94 THE GASOLINE AUTOMOBILE
for any desired relation between the damper and the throttle. Ordinarily
the hot air damper should be nearly horizontal when the throttle is closed.
63. Stromberg Model H. — The Stromberg Model H carburetor,
shown in Fig. 109, is of the double-jet type with two adjustments, for
high and low speed, both working on the gasoline supply.
The gasoline in the glass float chamber is regulated by the hollow metal
float. The fuel for low speed is furnished by the spray nozzle in the ven-
turi tube, through which the low speed air passes. The adjustment for
this nozzle is by means of the needle valve, as shown.
At high speed, the auxiliary air comes through the auxiliary air valve,
which in turn automatically regulates the gasoline flow from the auxiliary
gasoline valve. This supplies the extra gasoline for high speed and heavy
duty service.
The dash pot with the piston riding in gasoline prevents all fluttering
of the air valve on its seat when opening and closing.
This type of carburetor is fitted with a strangling or choke valve in
the primary air inlet, for starting in cold weather. This assists in the
vaporization of the gasoline by increasing the suction on the liquid.
The spring tension on the air valve and auxiliary needle valve is con-
trolled either from the dash or from the steering post, depending upon the
style of control installed. This permits adjustments to be made in order
to compensate for varying conditions of weather, fuel, and operation.
64. Zenith Model L. — This carburetor, shown in Fig. 110, differs from
most conventional types in the absence of auxiliary air valves. It is a
"fixed" adjustment carburetor, and has as its particular feature the
"compound nozzle." The compound nozzle consists of an inner nozzle,
the gasoline for which is furnished direct from the float chamber. The
amount of gasoline leaving this nozzle varies with the suction and conse-
quently the mixture from this nozzle would be too rich at high speeds.
To compensate for this rich mixture, the compensating nozzle surround-
ing the main nozzle furnishes a mixture "too weak " at high speeds. This
is because the gasoline feed to this jet is constructed so as to be constant
at all speeds. When the engine speeds up, the amount of air increases
and the compensating mixture is a weak one. This answers the purpose
of the auxiliary air valve on other types of carburetors and keeps the
mixture of constant proportions. By a proper selection of the two nozzles
a well balanced mixture can be secured through the entire range.
In addition to the compound nozzle, the Zenith is equipped with a
starting and idling well. This well terminates in a priming hole at the
edge of the butterfly valve, where the suction is greatest when the valve
is slightly open. The gasoline is drawn up by the suction at the priming
hole and, mixed with the air rushing by the butterfly, gives a rich slow
speed mixture. The slow speed mixture is regulated by the regulating
FUELS AND CARBURETTING SYSTEMS
95
screw, which admits air to the priming well. At higher speeds with the
butterfly valve opened, the priming well ceases to operate and the com-
pound nozzle drains the well and compensates for any engine speed.
Fia. 110.— Zenith Model L carburetor.
65. Rayfield Model G. — This carburetor is illustrated in Figs. Ill and
112. It has two jets and the gasoline is drawn through them into
the mixing chamber, the quantity being controlled by adjustments on the
outside of the carburetor. As will be noticed, there are no air valve ad-
justments, but two gasoline adjustments, a low speed adjustment and a
high speed adjustment. The names of the lettered parts on Fig. Ill are
as follows:
D —Throttle Arm.
G — Priming Lever.
H —Gas Arm.
M — Regulating Cam.
S — Drain Cock.
U — Needle Valve Arm.
X —Drain Cocks.
The suction created by the downward motion of the motor pistons
draws air into the mixing chamber through the primary and auxiliary
air inlets. This air rushes through the mixing chamber, around the nozzle
96
THE GASOLINE AUTOMOBILE
and the metering pin, and picks up the gasoline which leaves the nozzle
and jet in the form of a spray. Thus the action of the mixing chamber is
not unlike that of an ordinary atomizer in which the air, forced from the
rubber bulb, picks up a certain amount of the liquid in the bottle and
sprays it out in the form of a fine vapor.
That the proportion of air and gasoline in the mixture may be correct
for all motor speeds, one fixed air inlet and two variable auxiliary air
inlets are provided. The lower air valve opens and closes with the main
or upper automatic air valve, giving a greater volume of air in proportion
to the greater amount of gasoline to be vaporized. In other words, at
high motor speeds or when the throttle is fully opened, the motor requires
more gas and consequently a greater volume of air to vaporize the gasoline
HIGH SPEED
ADJUSTMENT
FIG. 111.— Rayfield Model G carburetor.
which comes through the spray nozzles; at low mo tor speeds, less gas is
required and consequently less air is necessary to vaporize the gasoline.
At the front end of the carburetor is the main auxiliary air valve.
This is controlled by a spring and dashpot. At low speeds, when only a
small amount of air is being drawn through the carburetor, the spring and
dashpot hold this valve almost shut. As the speed increases and more
air is needed, the suction operating against the tension of the spring draws
the valve further and further open, thus giving an increased supply of
air in proportion to the need for the increased speed. The motion of this
valve moves the metering pin and admits an additional supply of gasoline
at this second nozzle.
Rules for Adjusting Rayfield Model G.— With throttle closed, and dash
control down, close the nozzle needle by turning the low speed adjustment
FUELS AND CARBURETTING SYSTEMS
97
to the left until block U slightly leaves contact with the cam M . Then
turn to the right about three complete turns. Open the throttle not more
than one-quarter. Prime the carburetor by pulling steadily a few seconds
on the priming lever G. Start the motor and allow it to run until warmed
up. Then with retarded spark, close the throttle until the motor runs
slowly without stopping. Now, with the motor thoroughly warm, make
the final low speed adjustment by turning the low speed screw to the left
until the motor slows down and then turn to the right a notch at a time
until the motor idles smoothly.
To make the high speed adjustment, advance the spark about one-
quarter. Open the throttle rather quickly. Should the motor back-fire,
it indicates a lean mixture. Correct this by turning the high speed ad-
justing screw to the right about one notch at a time, until the throttle
can be opened quickly without back-firing.
FIG. 112. — Section of Rayfield Model G carburetor.
If "loading" (choking) is experienced when running under heavy
load with throttle wide open, it indicates too rich a mixture. This can be
overcome by turning the high speed adjustment to the left.
66. Carter Model C. — The Carter carburetor, shown in section in
Fig. 113, is of unconventional design and construction in many ways.
The float is of copper and is spherical in shape. The float valve is pro-
vided with a shock absorber to prevent the valve from pounding on its
seat when the car is being driven over rough roads.
There are three adjustments, for low, intermediate, and high speeds.
The adjustable fuel tube gives the advantages of multiple jets. For low
speeds the air taken in just above the bottom of the fuel tube takes
gasoline from around the bottom of the tube. Under increased suction
the gasoline is sucked higher in the tube and is sprayed through a number
of openings in the side of the fuel tube into the air coming through the
98 THE GASOLINE AUTOMOBILE
intermediate air valve. The high speed air adjustment is made from a
lever connection on the dash.
67. General Rules for Carburetor Adjustment.— Very few general
rules can be given for the adjustment of a carburetor. It is usually a
very wise plan to let well enough alone, but if adjustments are necessary,
it is very essential that they be made by someone familiar with the carbu-
FIG. 113.— Carter Model C carburetor.
retor, or that the manufacturers' instructions be followed out in detail.
The common carburetor troubles and remedies will be taken up in
Chap. IX.
On most types of carburetors, there are two adjustments to be made,
a low speed adjustment and a high speed adjustment. The low speed
adjustment is made with the engine running idle, the spark retarded, and
the throttle about one-quarter open. This is usually the gasoline adjust-
ment. The high speed, or auxiliary air adjustment, is made with the en-
gine running with throttle open and spark advanced. In all cases the
adjustment should be made after the engine has warmed up to its normal
running temperature.
Judging the mixture is largely a matter of experience. A rich mixture
is indicated by the overheating of the cylinders, waste of fuel, choking
of the engine and mis-firing at low speeds, and by a heavy black exhaust
smoke with a very disagreeable odor. A weak mixture manifests itself
by back-firing through the carburetor and by loss of power. A proper
mixture will give little or no smoke at the exhaust. Blue smoke is caused
by the burning of excess lubricating oil and has no relation to the quality
of the mixture.
FUELS AND CARBVRETTING SYSTEMS
99
68. Carburetor Control Methods.— The carburetor is controlled from
the driver's seat. The hand throttle on the steering post regulates
the amount of mixture to the cylinders, thus regulating the engine and
car speed. In conjunction with the throttle connection, is the ac-
celerator on the toe-board, which permits the throttle to be opened by
the foot, independently of the hand lever. The accelerator must be
held open by the pressure of the foot. As soon as pressure is removed
from it, the throttle closes to the point set by the hand lever. The air
and gasoline adjustments are usually made from the dash of the car.
69. The Gravity Feed System.— There are numerous systems for
feeding the gasoline to the carburetor from the gasoline tank, which
may be placed at tho rear of the frame, in the cowl, or under the seat.
These feed systems are classified as gravity, pressure, and vacuum systems.
FIG. 114. — Studebaker gravity feed system.
In the gravity system of gasoline feed, the fuel flows to the carburetor
by gravity alone. The tank may be placed either under the seat or in the
cowl. If under the seat, there is the disadvantage of having to remove
the cushions before being able to fill the tank. There is also the possi-
bility in some cases that the tank will become lower than the carburetor
when going up hill, and consequently the gasoline will not flow. Both
of these disadvantages are done away with by placing the tank in the
cowl. In either case, however, the pressure on the carburetor float valve
varies as the level in the tank varies. When filling the tank, any gaso-
line which spills or leaks either falls around the seat, in the car, or on the
engine. The advantage of the gravity system is that it is simple and
always ready. Figure 114 shows the gravity system used on the Stude-
100 THE GASOLINE AUTOMOBILE
baker car, with the tank in the cowl. This shows the float operating the
gasoline indicator.
70. The Pressure Feed System.— When the gasoline tank is placed at
the rear of the frame, it is obviously impossible to use the gravity system.
By putting a pressure in the gasoline tank, the gasoline may be forced by
pressure to the carburetor. The pressure is maintained by a small air
pump operated by the engine, or by a hand pump, or both. After filling
the tank, a hand pump is used to get up pressure until the engine has
been started. A safety valve in the pressure system keeps the pressure
from getting too high. A particular advantage of this type of feed
W..-SJ,,
Shut.0« G»olta.
tor Check'
FIG. 115. — Pressure feed system.
system is that gasoline feeds to the carburetor regardless of the position
of the car. As in the gravity system, the pressure on the float valve is
liable to vary. The filler cap is placed away from the engine and pas-
sengers, and gasoline may be put in without disturbance. A typical
pressure feed system is illustrated in Fig. 115.
71. The Vacuum Feed System. — Several systems have been developed
in which the gasoline is transferred from the main tank at the rear of the
car by vacuum, or suction, to a small auxiliary tank near the engine.
From this small tank it flows by gravity to the carburetor. Figures 116
and 117 show the installation of the Stewart vacuum system in a car, and
Fig. 118 indicates the construction of the auxiliary vacuum tank.
This system comprises a small round tank, mounted on the engine
side of dash. This tank is divided into two chambers, upper and lower.
The upper chamber is connected to the intake manifold, while another
pipe connects it with the main gasoline tank. The lower chamber is
connected with the carburetor.
FUELS AND CARBURETTING SYSTEMS
101
The intake strokes of the motor create a vacuum in the upper cham-
ber of the tank, and this vacuum draws gasoline from the supply tank.
As the gasoline flows into this upper chamber, it raises a float valve.
When this float valve reaches a certain height, it automatically shuts
off the vacuum valve and opens an atmospheric valve, which lets the
gasoline flow down into the lower chamber. The float in the upper
FIG. 116. — The Stewart vacuum feed system.
chamber drops as the gasoline flows out, and when it reaches a certain
point it in turn reopens the vacuum valve, and the process of refilling
the upper chamber begins again. The same processes are repeated
continuously and automatically. The lower chamber is always open
to the atmosphere, so that the gasoline always flows to the carburetor
as required and with an even pressure.
FIG. 117. — Under the hood. — The Stewart vacuum feed system.
The amount of gasoline always remaining in the tank gets some heat
from the motor and thereby aids carburetion; it also makes starting
easier, by reason of supplying warm gasoline to the carburetor. The
lower chamber of the tank is constructed as a filter, and prevents any
water or sediment that may be in the gasoline from passing into the
carburetor. A petcock, in the bottom of the tank, permits drawing off
102
THE GASOLINE AUTOMOBILE
this sediment and also allows the drawing of gasoline, if required for
priming or cleaning purposes.
72. Intake Manifolds.— The tendency in present engine design is
to make the intake manifold of such shape and proportions that the
path from the carburetor to the engine cylin-
ders shall be as short and smooth as possible.
Being close to the cylinders, the manifold as
well as the carburetor is heated, greatly aiding
the vaporization of the gasoline. The short
manifold gives the gas very little chance to
condense between the carburetor and the
cylinders. It is also desirable to have the
distance from the carburetor to the different
cylinders the same in all cases. This insures
the same amount of mixture to each cylinder.
73. Care of Gasoline. — Gasoline, being a
volatile liquid, is very dangerous if not
properly handled, but if proper care and at-
tention are given to it there should be no
danger whatever. It should never be ex-
posed in a closed room, as it will evaporate,
mix with the air, and form a very explosive
mixture. Open lights should always be kept
away from gasoline in all cases. When it is
necessary to handle gasoline at night, it
should be done with an electric light. Do
not under any conditions use an open light.
In putting out a gasoline fire, water will
only spread the fire, as the gasoline, being
FIG. 118. — Stewart vacuum lighter than water, floats on it. The only
successful method of extinguishing a gasoline
fire is to smother it, either by sand, or a blanket, or by the gases from a
fire extinguisher.
The exhaust gases from a gasoline engine are very deadly. Do not
breathe them for any length of time. If it becomes necessary to run
your engine in a small garage with the doors closed, arrangement should
be made to pipe the exhaust to the outside air.
CHAPTER V
LUBRICATION AND COOLING
74. Friction and Lubricants. — The purpose of lubrication is to reduce
friction between moving surfaces. If parts moving on each other were
not separated by a film of lubricant, the surfaces would rapidly rub
away. Friction is a force that tends to retard the motion of one surface
over another. The frictional force depends on the nature of the surface,
and also on the kind of material. It is caused by the small projecting
particles which extend from the surface. The rougher the surface and
the softer the material, the greater the friction; or, the harder the material
and the smoother the surface, the less the friction. The more friction
there is, the greater the loss of power, as it requires power to overcome
friction. A great amount of friction is necessary in certain parts of the
car in order that they be efficient, such as in the brakes, the clutch, and
the outer surface of the tires. On the other hand, it is essential that all
friction possible be eliminated from the bearings in order to have as little
of the motive power lost as possible.
The principal lubricants used are fluid oils, semi-solids, and sometimes
solids, such as graphite. There are three general sources of lubricants:
animal oils, such as lard, fish oil, etc.; vegetable oil, such as olive oil,
linseed oil, etc.; and mineral oils, which are secured from petroleum.
These lubricating mediums should each be used where they are best
adapted. An oil that is suitable for one part of the mechanism may not
be suited for another part. Only mineral oils should be used in gasoline
engine cylinders, as they alone meet the requirements. For this reason
the oils used for steam engine cylinders are not good for gasoline engine
use, as they do not withstand the high temperature which rises in the gas
engine cylinder. There are two main requirements for good cylinder
oil. It should have a high flash point, that is, it should not break down
and give off inflammable gases at low temperatures; and, second, it
should retain its body and not become so thin as to be worthless as a
lubricant at high temperatures. It should have sufficient body to
maintain a positive film between piston and cylinder, yet should not be
so heavy as to retard the free motion of the piston and rings. It should
also be free from acids or any form of vegetable or animal matter. The
vegetable or animal matter will decompose at high temperatures and
gum up the cylinder. The acid will etch the smooth surface of the
103
104 THE GASOLINE AUTOMOBILE
cylinder and cause excess friction. A simple method to test for acid is
to dissolve a little of the oil in warm alcohol and then dip a piece of blue
litmus paper in the solution. If there is any acid present, the paper will
turn red. The litmus paper can be obtained at any drug store.
76. Cylinder Oils. — Cylinder oils are usually classified in three
grades; light, medium, and heavy. Light cylinder oil looks something
like the ordinary machine oil, and is slightly more viscous. The medium
is somewhat heavier than the light, and might be compared to warm
maple syrup. Light and medium oils should be used only on engines
which have close-fitting pistons. The heavy oil is used in air-cooled
engines and in engines that have loose pistons or that become too hot
to use the lighter grade of oil. A good gas engine oil should have a
high degree of viscosity at 100°F., a flash point not under 400°, and a fire
test of over 500°.
76. Viscosity. — Viscosity is the property of a liquid by which it has a
tendency to resist flowing. Oils are tested for viscosity by being put in a
container and allowed to flow through a small opening. The oil that
flows the fastest has the least viscosity. In some parts of the automobile
it is necessary to use oil with less viscosity than in other parts. Tight
fitting bearings should use oil with very little viscosity, while meshed
gears should have semi-solid lubricants because the pressure on the
rubbing surfaces is very high.
77. Flash Point.^-The flash point is the temperature at which, if an
oil be heated and a flame held over the surface, the- vapor rising from the
oil will burst into flame, but will not continue to burn. A thermometer
is placed in the oil bath and the temperature taken at this point.
78. Fire Test and Cold Test. — Fire test is merely a continuation of the
flash point test; that is, the temperature at which the vapor which rises
from the oil will continue burning, and not merely flash for a second.
Both these tests are used only on cylinder oil.
There is another test that is called the "cold test," which indicates
the temperature at which the oil hardens, or becomes so stiff as not to
flow. Good cylinder oil should not become so stiff as to prevent reaching
the desired points at zero temperature.
79. General Notes on Lubrication. — There is no one thing which is
the primary cause of more trouble and the cause of more expense
in maintenance to the mechanism of an automobile than insufficient
lubrication.
All moving parts of a car are usually manufactured with a high degree
of accuracy and the parts are carefully assembled. In order to maintain
the running qualities of the car it becomes necessary to introduce sys-
tematically suitable lubricants between all surfaces which move in con-
tact with one another.
LUBRICATION AND COOLING 105
The special object of this chapter is to point out the places in the car
which require oiling. While it is manifestly impossible to give exact
instructions in every instance as to just how frequently each individual
point should be oiled or exactly how much lubricant should be applied,
we can give this approximately, based on average use.
It should be borne in mind that friction is created wherever one
part moves upon or in contact with another. Friction means wear, and
the wear will be of the metal itself unless there is oil, and oil is much
cheaper than metal. The use of too much oil is better than too little,
but just enough is best.
Proper lubrication not only largely prevents the wearing of the parts,
but it makes the car run more easily, consequently with less expense for
fuel and makes its operation easier in every way.
The oiling charts shown in this chapter indicate the more important
points which require attention. But do not stop at these. Notice the
numerous little places where there are moving parts, such as the yokes
on the ends of various connecting rods, and pull rods, etc. A few drops
of oil on these occasionally will make them work more smoothly.
Oil holes sometimes become stopped up with dirt or grease. When
they do, clean them out and be careful not to overlook them. Also be
careful not to allow dirt or grit to get into any bearings.
Judicious lubrication is one of the greatest essentials to the satisfac-
tory running and the long life of the motor car. Therefore lubricate, and
lubricate judiciously.'
The auto engine should be lubricated by some means that will insure
a definite supply of lubricant to the moving parts and that will supply
the loss caused from vaporizing, burning and leakage.
The differential, axle bearings and shift gears are lubricated with semi-
solid grease. The rear axle is not oil-tight, and therefore a fluid oil
should not be used. Semi-solid lubricants also help to cut down the
noise and wear where the pressure is heavy, and have sufficient cushion so
that they adhere to the gear teeth. The lighter oils are better adapted
for the high speed close-fitting parts. Other moving parts may be
lubricated with the ordinary oil can, but are generally lubricated by the
compression cup system. These cups may be screwed up from time to
time to add more lubricant to the bearing surfaces.
The transmission should always contain sufficient lubrication to bring
it up to the level of the drain plug on the side of the case, or so that the
under teeth of the smallest gear will enter to their full depth.
The differential case should contain enough lubricant to bring it up
to the filling hole, or should be about one-third full.
Wheel bearings should be packed with a thin cup grease. Do not
use a heavy grease because it will work away from the path of the roller
106 THE GASOLINE AUTOMOBILE
or ball and will not return. In each hub there is usually a small oil hole.
Inject some engine oil here whenever you are oiling the car. It will keep
the grease soft and in good condition. Before lubricating any part,
wipe all dirt from it so that the dirt will not get into the bearings.
The steering gear is perhaps one of the most important parts of the
car to keep properly lubricated. Failure of the steering apparatus is a
dangerous thing and a few drops of oil given to the oil cups and the
various steering connections constitute a cheap and safe means of avoid-
ing accidents. Most types of steering apparatus are packed with grease
which, having no outlet, will remain. However, the grease will become
dry and a little oil should be added from time to time.
Few motorists think of lubricating their brake connections. Mud
and water will find their way into the brake mechanism and a squeeze of
the oil can and a turn of the grease cups, given daily will keep them in
good working condition.
The principal engine lubricating systems can be grouped under the
following heads: first, splash system; second, splash with circulating
pump, which maybe either a "forced feed" or a "pump-over" system;
third, full forced feed; fourth, mixing the oil with the gasoline.
80. Splash System of Engine Lubrication. — The splash system is used
in the Ford engine, as shown in Fig. 119. The oil is poured directly into
the crank case until it comes above the lower oil cock. The level of the
oil should be maintained somewhere between the two oil cocks. The
flywheel runs in the oil and picks up some of it and throws it off by cen-
trifugal force; some of the oil is caught in a tube and carried to the front
end of the crank case where it lubricates the timing gears. As the oil
flows back to the rear part of the crank case, it fills the small wells in the
crank case under each connecting rod. As the connecting rod comes
around, a small spoon or dipper on the bottom scoops up the oil, so that
there is a regular shower of oil all the time. The pistons, cylinder
walls, and bearings are lubricated in this manner and the oil is kept in
continuous circulation. All parts of the clutch and transmission are
lubricated in the same manner as the engine.
The oil level should never get below the lower oil cock and should
never get above the upper oil cock. Never test the level of the oil when
the engine is running.
81. Splash System with Circulating Pump. — This system has an oil
reservoir or sump below the main crank case bottom. The oil from
the sump in the lower half of the crank case is sucked through a strainer
into the pump, usually at the rear end of the reservoir. The oil pump
of the Buick engine is shown in Fig. 120. This pumps the oil up through
a pipe to a sight feed on the dash so that the circulation can be observed
by the driver. From here the oil returns to the splash trays in the lower
LUBRICATION AND COOLING
108
THE GASOLINE AUTOMOBILE
half of the crank-case through the distributor pipe. As the crank comes
around, the spoons or dippers on the connecting rods dip into these
trays and force some of the oil up into the crank pin bearings and splash
the remainder over the interior of the crank case and up into the cylinders
and pistons. As the oil drains back, it is caught in ducts and led to all
the bearings of the motor, the excess running back into the sump to be
used again.
The oil circulating pump consists of two small gears enclosed in a
close fitting housing attached to the lower half of the crank case and
driven by a vertical shaft and spiral
gears from the cam shaft. As the gears
turn, they take the oil into the spaces
between the teeth and carry it around
to the outlet where the action of the
teeth meshing together squeezes the oil
out of the spaces and forces it to flow to
the sight feed on the dash. The pump
requires no attention or adjustment ex-
cept the addition of fresh oil to the
crank case reservoir as often as is
necessary to keep the oil level up to the
oil cock. The sight feed on the dash
merely shows whether or not the oil is
circulating and does not show when the
supply in the crank case is running low.
Test the oil level at frequent intervals
by opening the oil cock and see that the
oil is kept up to this level. To remove
the pump, draw off all the oil and take
the pump out from below.
The motor lubrication on the Overland car is shown in Fig. 121, '
and is the splash and pump-over system. The oil reservoir is located
m the bottom of the crank case and is filled through the combination
breather pipe and oil filler on the right side of the engine. The glass
gauge on the side of the crank case close to the breather pipe indicates the
oil level. The oil pump, which is located in the rear of the crank case, is
driven from the cam shaft. The lubricant is drawn from the base and,
after passing through a strainer, runs through a sight feed on the dash,
and from there it runs into the troughs and is splashed into the bearing
surfaces. It is very important that the oil strainer be kept clean at all
;imes so that proper circulation of the 'oil is insured. For this reason
B removal of the oil strainer has been made easy. By unscrewing the
large plug on the side of the crank case right opposite the oil pump, the
FIG. 120, — Buick oil pump.
LUBRICATION AND COOLING
109
cylindrical screen may be drawn out 'and cleaned by dipping into a pail
of gasoline. The^ owner should see that the oil screen is cleaned every
200 miles of the first 1000 miles and after that every 500 miles.
The lubricant circulates freely through the system as long as the small
wheel in the dash sight-feed revolves. But as soon as the wheel stops
or the sight-feed glass shows clear, this is an indication that the oil supply
is exhausted, or that there is an obstruction in the circulation of the
oil which should be located and remedied immediately, since serious
and expensive trouble will result from running the motor with an in-
sufficient supply of oil.
FIG. 121. — Overland splash system with circulating pump.
The wrist pin is lubricated from the cylinder walls, through the
opening in the piston through which the wrist pin is inserted, as well as
through a slot cut into the connecting rod over the wrist pin bushing.
The lubrication system of the Studebaker Four, Fig. 122, is called
the constant level splash system combined with a forced feed to. the
timing gears. A quantity of oil is carried in a reservoir F, which is
formed by the crank case of the motor. A pump B of the plunger type
draws the oil from this reservoir and sprays it (G) over the connecting
rod bearings. It also pumps surplus oil through a sight feed J or indi-
cator on the dash, from which it flows over the timing gears D at the
110
THE GASOLINE AUTOMOBILE
front of the motor and returns to the reservoir through the pipe U.
The oil draining from the spray collects in troughs E which maintain a
constant level of oil just under the connecting rods. At each revolu-
tion short projections M from the connecting rods dip into these troughs
and splash oil over the lower ends of the pistons, and over the cam and
crank shaft bearings.
To fill the oil reservoir of the motor, pour the oil in through a funnel
shaped tube H, which you find on the left side of the motor. This
funnel shaped tube is called the "breather pipe." At the side of the
"breather pipe" there is a gauge / which shows the amount of oil in the
FIG. 122. — Studebaker splash system with forced feed.
reservoir. The' oil is poured into the breather pipe until the gauge
indicator rises to the highest point of the gauge, being careful that there
is no more oil poured into the motor than just enough to bring the in-
dicator to the highest point shown on the gauge. The only attention
necessary to keep the motor perfectly lubricated is to see that the gauge
indicator shows that there is oil in the reservoir.
When the motor is running, oil drops through a glass indicator or
"sight feed" J on the dash. This "sight feed" can be seen from the
seat. and should not be forgotten by the driver. If the oil should cease
to flow through the "sight feed" when the motor is running, the motor
should be stopped and hood lifted to ascertain if the gauge I shows
oil in the reservoir. If it does show oil in the reservoir, then either the
oil pump or the connecting oil pipes are clogged and should be cleaned
out.
LUBRICATION AND COOLING
111
82. Full Forced Feed System. — A full forced feed as used on the
Cadillac Eight is shown in Fig. 123. A gear pump located at the for-
ward end of the motor and driven from the crank shaft takes the oil up
from the oil pan in the lower part of the crank case and forces it through
a reservoir pipe running along the inside of the crank case, from which
pipe there are leads to each of the main bearings. The crank shaft and
webs are drilled and oil is forced from these main bearings to the con-
necting rod bearings through the drilled holes. The forward and rear
bearings supply the rod bearings nearest them, while the center bearing
PBESSURE GAUGE
ON DASH'
ADJUSTABLE
PEESSUI2E
VALVI
FIG. 123. — Cadillac forced feed oiling system.
takes care of the rod bearings on either side of it. The oil is then forced
from the main reservoir pipe up to the relief valve, which maintains a
uniform pressure above certain speeds, and overflows from this valve to
a pipe extending parallel with the cam shaft and above it. Leads from
this latter pipe carry lubricant by gravity to the cam shaft bearings and
front end chains. Pistons, cylinders and piston pins get their oiling by
the oil thrown from the lower ends of the connecting rods.
A gauge indicating the level of the oil is attached to the upper cover
of the crank case. Whenever the indicator reaches the space marked
"fill," oil should be added until the indicator returns to "full." A filling
hole is provided in each block between the second and third cylinders.
If the hand on the pressure gauge on the cowl vibrates or returns to zero
on the dial when the engine is running, it indicates that the oil level is very
H2 THE GASOLINE AUTOMOBILE
low. Should this occur through neglect to add oil at the proper time, the
engine should immediately be stopped and sufficient oil added to bring
the pointer up to the top of the gauge before the engine is again started.
The hollow crank shaft oiling system as used by the Wisconsin Motor
Mfg. Co. is shown in Fig. 124 and
operates as follows:
The oil is carried in an inde-
pendent chamber at the bottom
of the crank case, and the con-
necting rods are not allowed to dip
into this, thus preventing the oil
from being whipped to a froth,
and preserving its viscosity.
It is pumped by means of a
gear pump located at the lowest
point of the oil reservoir into a
main duct, which is cast integral
with the crank case, and from here
distributed by means of ducts,
drilled into the webs, to the main
bearings. From here it is forced
through a hollow crank shaft to
the connecting rod bearings, and a
sufficient amount of oil is forced
out of the ends of the bearings to
lubricate the pistons, piston pins,
and cam shafts. A separate lead
runs directly over the timing gears,
and all oil is thoroughly filtered
before it is pumped over again.
An oil gauge indicates by means of
a ball and float the exact amount
of oil contained in the reservoir,
and distinct marks on the glass
gauge show the high and low mark,
and if the oil is maintained be-
tween these two levels no burnt
oil smoke will be emitted, and the
spark plugs will not be fouled.
The pressure of the oil increases with the speed of the motor, so the
faster the motor is run the more oil is forced to it, and vice versa. The
location of the oil reservoir permits the proper cooling of the oil, thus
minimizing the danger of burning out bearings.
LUBRICATION AND COOLING 113
The lubricating system for Knight sliding sleeve motors is also of the
forced feed type. The following description is of the system used on the
Moline-Knight car. Oil is drawn from the sump by a gear pump driven
off the end of the eccentric shaft, and is delivered to the three main bear-
ings, and the magneto drive shaft bearing under a pressure determined
by the settings of a spring controlled by-pass valve, through which the
excess oil is delivered. This excess oil is led to the chain driving the
eccentric shaft and magneto, and flows thence to a trough and through a
screen to the sump. Part of the oil delivered to the main bearings passes
through holes in the crank shaft web to the crank pins, and thence through
the tubular connecting rod to the hollow piston pins. From the two
ends of the latter it flows to the sleeves and is distributed through holes
and oil grooves in the latter over their circumference and the cylinder
walls. All parts requiring lubrication not mentioned above are oiled
by splash from the crank shaft and connecting rods. The flow of oil
delivered under pressure is determined by a valve which is so connected
as to open and close with the throttle. There are no oil grooves in any of
the crank shaft bearings. The entire bottom of the crank case is covered
by a screen, through which the oil returns to the sump.
83. Mixing the Oil with the Gasoline. — Another system that is used
to some extent in two-stroke marine engines is to mix the lubricating oil
with the gasoline, in the proportion of 1 pt. of oil to 5 gal. of gasoline.
The easiest way is to thoroughly mix 1 pt. of oil with 1 gal. of gasoline,
pour it into the fuel tank and then add 4 gal. of gasoline. The oil stays
in solution with the gasoline. This system is very simple, as the lubri-
cating becomes automatic and there are no regulators to adjust.
When the piston is on the up stroke, a charge of gasoline and oil is
drawn through the carburetor. Here the oil and gasoline separate
because the oil does not evaporate and the gasoline does. The gasoline
mixes with the air in the form of a gas. The oil collects in the form
of small globules which float in the mixture of gas and air and are carried
into the crank case by the suction of the motor. Here some of the oil
settles on the connecting rod and crank and flows through a special oil
duct to the crank pin.
On the down stroke of the piston, the gas and oil are forced through
the by-pass into the cylinder where the remainder of the oil is deposited
on the cylinder walls. This operation' is repeated every revolution of
the engine, a new film of oil being supplied each time.
84. Selection of a Lubricant. — The proper lubrication of the motor
car is more important than any other item in its care. Only the best
high grade oils should be used to lubricate the engine. Some engines
require lighter oils than others on account of the close-fitting pistons and
rings. It is better to follow the instructions sent out by the manufac-
114 THE GASOLINE AUTOMOBILE
turers in regard to the kind of oil to use rather than for the motorist to
make his choice or to be directed by an oil salesman. The different com-
panies run extensive tests and find out in that way which oil is best suited
for their type of engine. The only way to get the best lubricants is to pay
the price. Money saved by cheap oils or grease may be more than lost
in worn-out bearings or cylinders.
The multiple-disc type of clutch is the only one in which any lubrica-
tion should be used, and the oil here should be drained off about every
1000 miles, the clutch well cleaned out with kerosene, and then filled with
light machine oil, the amount, of course, depending upon the capacity
of the case. All clutches that use any kind of facing, such as asbestos,
raybestos, or leather, should never be lubricated, as the oil decreases the
friction and causes slipping. Clutch leathers will retain their life and
softness better if given an occasional treatment of neatsfoot oil and then
wiped dry.
The planetary transmission system in the Ford automobile is encased
so as to revolve in an oil bath.
The differential housing and sliding gear transmissions and all other
parts that use either heavy cylinder oil, transmission oil, or graphite
grease, should be thoroughly cleaned every 1000 miles, or thereabouts,
and well flushed out with kerosene in order to remove all sediment and
metallic dust that may be in the old grease. All wheel bearings are of
the ball or roller anti-friction type, and are packed with semi-fluid
grease which should be renewed about every 1000 miles.
An excess of grease in the transmission or differential case will be shown
by leaking at the joints, on account of the difficulty of keeping these
members absolutely tight and still free to run. If there is too much
grease in the differential case, it will run along the axle shaft and out over
the oil guard, which is to prevent it from getting on the tire and also from
interfering with the action of the internal brake.
Excess of lubrication in the engine will produce carbon deposits and
dirty spark plugs. It may also cause the piston rings to gum up and stick.
It can be detected by the color of the exhaust smoke, which will have a
bluish tinge, or it may be detected by a sticky black coating on the spark
plug.
A small amount of graphite and oil or grease should be supplied be-
tween the leaves of the springs. This can generally be done by jacking
up the frame so that all weight is taken off the wheels, and by using
a small clamping device with wedge-shaped jaws, which can be used to
spread the leaves apart.
85. Directions for Lubrication.— A very good chart for lubrication
purposes is sent out by the Chalmers Motor Car Co., and of course can
be used for other standard makes of cars. This chart is as follows:
LUBRICATION AND COOLING
115
DIRECTIONS FOR LUBRICATION
EVEBT DAY CAB is IN USE, OB EVEBY 100 MILES:
Part
Crank case.
Steering knuckle grease cups.
Steering cross rod grease cups.
All spring bolt grease cups.
Speedometer driving gears.
Eccentric bushing of steering gear.
Wheel hub oilers.
Quantity
Keep oil at level of top try cock.
One complete turn.
One complete turn.
Two complete turns.
One complete turn.
10 or 15 drops.
10 drops.
TWICE A WEEK, OB ABOUT EVEBY 200 MILES:
Part Quantity
Fan hub bearing. Few drops.
Pump shaft grease cups. Two complete turns.
Steering gear case oiler. Fill.
Steering gear case grease cup. Two complete turns.
Steering wheel oil hole. 8 or 10 drops.
Steering column. 10 or 15 drops.
EVEBY WEEK, OB ABOUT EVEBY 300 MILES:
Part
Spark and throttle shafts.
Control bracket bearings.
Transmission case.
Pedal fulcrum pin.
Brake pull rods and connections.
Brake cross rod grease cups.
Torque rod grease cups, front and rear.
Brake shafts on rear wheels.
Rear spring perch grease cups.
Quantity
Few drops.
Thoroughly.
Enough to cover lower shaft.
Thoroughly.
Thoroughly.
Two complete turns.
Two complete turns.
Thoroughly.
Two complete turns.
TWICE A MONTH, OB EVERY 500 MILES:
Part Quantity
Magneto bearings (3 oil holes). 3 or 4 drops each.
Dynamo drive shaft universal joints. Fill one-half full.
EVEBY MONTH, OB EVERY 1000 MILES:
Lubricant
Motor oil.
Cup grease.
Cup grease.
Cup grease.
Cup grease.
Motor oil.
Motor oil.
Lubricant
Motor oil.
Cup grease.
Motor oil.
Cup grease.
Motor oil.
Motor oil.
Lubricant
Motor oil.
Motor oil.
Motor oil.
Motor oil.
Motor oil.
Cup grease.
Cup grease.
Motor oil.
Cup grease.
Lubricant
High grade light ma-
chine oil.
Cup grease.
Part
Crank case.
Reach rod boots.
Spring leaves. (Jack up frame and
pry leaves apart.)
Hub caps.
Universal joints.
Gasoline pressure hand pump.
Quantity
Drain off dirty oil; clean oil screen at
left of motor thoroughly; fill to
level of top try cock.
Pack thoroughly.
Thoroughly.
Pack thoroughly.
Remove grease hole plug and fill one-
half full.
4 or 5 drops on leather plunger.
Lubricant
Motor oil.
Cur
Graphite grease.
Cup grease.
Cup grease.
Light machine oil.
EVEBY 2000 MILES:
Part
Differential housing.
Transmission case.
Quantity
3pt.
Drain thoroughly, flush with kero-
sene, refill to cover top lower
shaft try cock.
Lubricant
Special axle compound.
Motor oil.1
Dynamo should be lubricated every 3000 to 5000 miles.
When changing tires, put a few drops of oil on inside sliding ring of demountable rims to insure easy
detaching.
116
THE GASOLINE AUTOMOBILE
QREAiftg
LUBRICATION AND COOLING 117
Figure 125 shows the location of the various places to be lubricated
and the proper intervals for lubrication. This is the chart for the Case
car.
86. Cylinder Cooling. — When an explosion occurs inside the cylinder
of a gas engine, the gases on the inside reach a temperature of from 2000°
to 3000°F. The walls of the cylinder are, of course, exposed to this high
heat and would very quickly get red hot if we did not have some way of
keeping them cool. The polished surface upon which the piston slides
would be very quickly spoiled. The most common way of keeping a
cylinder cool is by the use of water. Surrounding the cylinder is a metal
jacket enclosing a space for the cooling water. By keeping a supply of
water passing through this space, the cylinder can be kept cool enough
for the operation of the engine. The cylinder head is also cast with a
double wall, especially around the valves, so that these parts will also be
kept cool. The cooling fluid used is generally water.
Water should not be allowed to remain in the jacket of an engine over
night if there is danger of a frost, as the freezing of the water will crack the
cylinder. When the supply of water is limited, as in an automobile,
the water is cooled in a radiator or system of pipes, and then is used over
again. The water is kept in circulation by a pump, or by the thermo-
syphon system, and the hot water is cooled by the air passing over the
radiator.
The circulation in the thermo-syphon system is based on the fact that
cold water is heavier than hot water, and consequently, the water heated
in the cylinder jackets flows up and over into the top part of the radiator,
where it is cooled and then flows from the lower portion of the radiator
back to the engine cylinder. Circulation is automatically maintained as
long as the engine is hot and there is enough water in the radiator so that
the return connection from the cylinder to the radiator contains water.
This means that the radiator must be kept practically full all the time, or
else there will be no circulation and the water will merely boil away.
When the pump system of circulation is used, the radiator may be
lighter than in the syphon system, as less water is needed to do the same
amount of cooling. The pump is driven from the engine, and the faster
the motor runs the faster the water circulates. The centrifugal type of
pump is generally used for circulating cooling water.
87. Water Cooling Systems. — Radiators differ in design. In some
types the water flows through tubes of very small diameter. In this
type it is necessary to have a circulating pump of some kind. In radia-
tors having tubes of larger diameter, the thermo-syphon system may be
used. The radiators using the small pipes have a greater capacity for
their size because they have more exposed area for cooling in comparison
with the amount of water they carry. The small tubes have the dis-
118 THE GASOLINE AUTOMOBILE
advantage of increased resistance. This is why it is necessary to use a
pump.
The air for cooling purposes is usually drawn through the radiator
by a fan placed directly back of it. This fan may be driven with a bevel
or spur gear, with a silent chain, or with a wire or leather belt. In some
cases, however, the engines are air-cooled, the cylinders being cast with a
large 'number of fins or rings on the outer surfaces to increase the cooling
effect of the air. In this case there is no water jacket.
The cooling system of the Overland is the thermo-syphon system,
which eliminates the circulation pump and its gears, glands, stuffing boxes,
FIG. 126. — Overland thermo-syphon cooling system.
etc. The thermo-syphon system is automatic, as the speed with which
the cooling water circulates is increased or decreased with every increase
or decrease in jacket temperature. The action of the system is, briefly, as
follows: The water enters the cylinder jackets A, Fig. 126. Upon
becoming heated by the explosions within the cylinders, the water ex-
pands and, being lighter, rises to the top. It then enters the pipe B and
passes into the radiator at C, where it is brought into contact with a large
cooling surface, D, in the shape of the cellular radiator. On being cooled,
and thereby contracting and becoming heavier, the water sinks again to
the bottom of the cooling system, to enter the cylinders once more and to
repeat its circulation. The cooling action is further increased by a belt-
driven fan which draws air through the radiator spaces.
LUBRICATION AND COOLING
119
Figure 127 shows the cooling system on the Ford. This is also a
thermo-syphon system, the principle of operation being the same as on
the Overland. The arrows indicate the path of the cooling water.
The cooling system used on the Studebaker Four is the pump system
shown in Fig. 128. The water system, which contains 10 qt. of water,
consists of a radiator, hose connections, water line, pump, and water
jackets which are incorporated with the cylinders. The radiator D
being filled with water and the motor running, the centrifugal pump C
forces the water to circulate as follows: From the pump it is driven
FIG. 127. — Ford cooling system.
through the lower water line into the cylinder water jacket, directly at
the valve seats, where perfect cooling is most needed. Here it absorbs
the heat and goes on to the upper water line and thence to the radiator.
In the radiator D the water percolates slowly down through many fine
tubes F and is cooled by the air rushing between the fins surrounding the
tubes and thence returns to the pump. A fan G on the front of the
motor, belted to the crank shaft, draws the air through the radiator and
facilitates the cooling operation. Figure 128 also shows a standard
design of tubular radiator. The pump, which is of the centrifugal type,
requires no attention other than to see that it does not become choked
by using dirty water. There is a packing nut on the shaft which should
be repacked if the pump should ever leak around the shaft entrance.
12o THE GASOLINE AUTOMOBILE
This can very easily be done by turning off the packing nut, removing the
old packing and rewinding the shaft with a few inches of well graphited
packing and tightening up the packing nut. The packing should be
wound on in the same direction as the nut is turned to tighten it.
The cooling system on the Cadillac Eight is of the forced circulation
type. The radiator is of the tubular and plate type, with rotating fan
mounted on the forward end of the generator driving shaft, the latter
DRAIN COCK. A-
FIG. 128. — Studebaker cooling system.
being driven by silent chain from the cam shaft. Each set of cylinders is
cooled separately. Due to the angle of jackets, the water does not lodge
in the pockets. The natural tendency is for the water to flow upward
and to rise to the hottest points.
There are two centrifugal water pumps, one on each side of the
forward end of the engine. These are driven by a transverse shaft which
is driven by spiral gears from the crank shaft. Within each pump hous-
ing is a thermostat shown in Fig. 129, which controls a valve that is
between the radiator and the pump.
When the temperature of the cooling water drops below a pre-
determined temperature, the thermostats contract, thereby closing the
LUBRICATION AND COOLING
121
valves. The water is then circulated only through the cylinder blocks
and the carburetor jacket. It returns to the pumps through the water
jacket on the intake manifold and carburetor. When the thermostats
are closed, none of the water circulates through the radiator the evapora-
tion of the gasoline in the carburetor and manifold providing sufficient
cooling action. As the temperature of the water rises, the thermostats
expand, thereby gradually opening the valves, permitting the water to
circulate through the radiator.
FKOM T2ADUTOI2.
PEOMCAEBUJ5JCTIB
JACKET '
FIG. 129. — Cadillac thermostatic control of cooling water.
The advantage in this device is that, in starting with a cold en-
gine, the engine is brought to a point of highest efficiency, in so far as
heating is concerned, much more quickly than if it were necessary to
heat the entire volume of water before reaching that efficiency. With
the usual water circulating system, the highest efficiency of the engine
is not reached in extreme cold weather. An engine uses its gasoline
most economically when it is running rather warm, and with a radiator
which is adequate to prevent overheating in hot weather, the cooling
is too great for best economy in extreme cold weather.
The Cadillac thermostat is simply a small corrugated copper tube
containing a liquid which expands or contracts in accordance with the
temperature, thus slightly lengthening or contracting the tube, its total
movement being 34 in. This thermostat is in connection with a valve
so that, when it expands, it raises the valve from its seat, this valve con-
trolling the flow of water to the radiator from the pump. A by-pass
122
THE GASOLINE AUTOMOBILE
connects with the water jacket of the carburetor, and when the engine
is started, the water is naturally cold. Therefore the thermostat is
contracted and its valve is seated. Thus the radiator water is shut off,
the circulation being simply through the water jackets of the cylinders,
through the by-pass to the carburetor jacket and thence back to the
cylinders. There is thus only a small part of the water circulating, and
when this heats up, the thermostat begins to expand and lifts its valve
from its seat, letting the radiator supply flow into the system. This
action continues back and forth so that the water temperature is nearly
constant.
88. Air Cooling. — The Franklin engine, shown in Fig. 130, shows a
good design of an air cooling system. The direct air cooling of the engine
FIG. 130. — Franklin air cooling system.
is accomplished as follows: The individual cylinders are provided with
vertical fins projecting from their periphery. The fins on each cylinder
are surrounded by sheet metal jackets which form passages for the air.
The flywheel is provided with a number of curved blades so that it has a
blower effect whenever the engine is running. This forms a partial
vacuum and sucks air into the space underneath the hood through the
grille in front. This air passes in uniform quantities down through the
individual jackets on each cylinder into the compartment below the
engine deck and hence out through the fan blades. The fan is incor-
porated in the flywheel and driven directly by the engine; so a steady
stream of fresh air is being continually drawn down over the cylinders
as long as the engine is running.
LUBRICATION AND COOLING 123
89. Cooling Solutions for Winter Use. — In climates where the tem-
perature does not go below a dangerous freezing point, the cooling
medium used is water; but in cold regions, where cars are run a good
deal in the winter, it is necessary to get spme kind of anti-freezing
solution. The ideal requirements for an anti-freezing compound are
as follows:
1. It should have no harmful effect on any part of the circuit with
which it comes into contact.
2. It should be easily dissolved or combined with water.
3. It should be reasonably cheap.
4. It should not waste away by evaporation, that is, its boiling point
should be as high as that of water.
5. It should not deposit any foreign matter in the jackets or pipes.
The principal materials used are: (1) oil; (2) glycerine; (3) calcium
chloride; (4) alcohol; (5) mixture of alcohol and glycerine; (6) kerosene
oil.
Oil has the advantage of having a very high boiling point so that
it will not waste away, but it has the disadvantage that it does not
make a good mixture with water, and will not absorb heat as rapidly as
water. It also has a lower heat coefficient, that is, it takes less heat to
raise the temperature of a certain amount of oil one degree, than it does
the same amount of water. Oil cannot be used where there is any rubber
in the circuit. It will attack rubber hose and gaskets very quickly and
they will deteriorate rapidly.
The disadvantages of using glycerine are similar to those of the
oil, chief of which is sure destruction to the rubber connection. It also is
liable to contain free acids, and it is quite expensive.
Calcium chloride makes a very good solution with water, the freezing
point depending upon the proportions used. The general solution is to
use 5 Ib. of the salt to 1 gal. of water. This solution will stand 39° below
zero before freezing. It has the disadvantage of being very apt to cause
electrolytic action where two metals are joined together. It is derived
from hydrochloric acid, and is liable to contain free acids, which attack
the metal very rapidly. Calcium chloride has the same appearance as
chloride of lime, but has a somewhat different chemical composition.
Pure calcium chloride is the only thing that can be used. The com-
mercial chloride of lime sets up electrolytic action. The solution may
be tested for acid by dipping a piece of blue litmus paper in it. If there
is any acid present, the paper turns red. As the water is evaporated in
the radiator there will be a crust formed on the inside of the jacket, and
also in the pipes, which has a tendency to clog up and prevent circulation.
The rate at which these deposits occur depends on the strength of the
solution.
124 THE GASOLINE AUTOMOBILE
Denatured alcohol seems to be about the best substance to use as a
non-freezing solution, as it has no destructive action whatever on either
metal or rubber, makes no deposits and never causes electrolytic action.
A solution of 50 per cent water and 50 per cent alcohol will stand about
32° below zero. The only disadvantage that it has is that it evaporates
more readily than the water, so that when adding new solution, more
alcohol than water must be added in order to keep the solution of the
same strength. The combination of alcohol, glycerine and water seems
to give very good results. In this combination, equal parts of alcohol
and glycerine are used. The alcohol has a tendency to overcome the
destructive action of the glycerine or the rubber connections, and the
glycerine keeps the alcohol from evaporating too rapidly. The freezing
point depends on the strength of the solution. A solution of 60 per cent
water, and 20 per cent each of alcohol and glycerine freezes at 24° below
zero. The proportions must be governed by the locality in which they
are used.
There are also numerous anti-freezing compounds on the market.
These are mostly put up from some of the materials mentioned here.
In the following tables are results showing the temperature at which
some of the well known anti-freezing solutions will freeze, in various pro-
portions of mixture with water and with one another. These are neces-
sary, as different localities and different altitudes require different solu-
tions and every person should be able to select his solution in the right
proportion to avoid having any trouble in the coldest possible weather
likely to be experienced in his home location.
FREEZING POINTS OP CALCIUM CHLORIDE SOLUTIONS
Per cent by volume of Specific gravity of Frppzini? noint
calcium chloride solution
10
1.085
22°F.
15
1.131
13°F.
20
1.119
0°F.
22
1.200
-9°F.
24
1.219
- 18°F.
26
1.242
- 28°F.
28
1.268
- 42 °F.
The
specific gravity is
given to be used
as a check on
proportions.
FREEZING POINTS OP DENATURED ALCOHOL MIXED WITH WATER
Per cent by volume of
alcohol
Specific gravity of
solution
Freezing point
10
0.988
24°F.
20
0.975
14°F.
30
0.964
— 1°F
40
0.954
- 20°F.
50
0.933
- 32 °F.
60
0.913
- 45°F.
70
0.897
- 57°F,
the
LUBRICATION AND COOLING 125
If wood alcohol be used instead of denatured alcohol, slightly lower
temperatures can be reached with the same proportions of alcohol and
water.
FREEZING POINTS OP ALCOHOL AND GLYCERINE MIXED WITH WATER
Alcohol and glycerine Water Freezing point
15 per cent 85 per cent 20°F.
25 per cent 75 per cent 8°F.
30 per cent 70 per cent — 5°F.
35 per cent 65 per cent — 18°F.
40 per cent 60 per cent — 24°F.
45 per cent 55 per cent — 30°F.
50 per cent 50 per cent - 33°F.
CHAPTER VI
BATTERIES AND BATTERY IGNITION
All automobile engines in use at the present time have some form
of electric ignition, in which a current of electricity is made to produce a
spark inside of the cylinder. All ignition systems are made up of two
essential parts: (1) the source of electric current supply; and (2) the
apparatus for utilizing this current to produce a spark in the cylinder.
Before considering the features of either of these component parts
it is necessary that an understanding be had of the fundamental electrical
principles and definitions governing the construction and operation of
electric ignition systems.
90. Fundamental Electrical Definitions. — An electric current flow-
ing in a wire can be compared to water flowing in a pipe line. As the
water pressure is measured in pounds per square inch, so the electrical
pressure in a wire is measured by a unit called a "Volt." It is the practical
unit by which electrical pressures are measured.
The "Ampere" is the practical unit by which the rate of current flow
in a wire is measured. It corresponds to the number of cubic feet or
gallons which flow through a water pipe per unit of time. For a large
number of amperes, a large wire is necessary and for a smaller number
of amperes, a smaller wire can be used. We can have a small wire carry-
ing a current of high voltage, and a large wire carrying current of low
voltage, just the same as a large or small pipe can carry water of either
high or low pressure. The size of wire determines the quantity of current
it can carry. A small wire can carry a small current but it requires a
large wire to carry a large current.
The "Ohm" is the unit by which the resistance to the flow of electric
current through a wire is measured. It corresponds to the friction op-
posing the flow of water through a pipe.
The Ampere-hour is the measure of quantity of current. One
ampere-hour is the amount of current which would flow at the rate of
1 amp. in 1 hour. It is by this unit that the capacity of storage batteries
is measured. A 60 ampere-hour battery will give current at the rate of
60 amp. for 1 hour, or at the rate of 30 amp. for 2 hours, or at the rate of
1 amp. for 60 hours, etc.
91. Direct and Alternating Current. — Electric current can be of two
kinds : direct or alternating. Direct current always flows in one direction
in the wire, and is the kind of current which is given out by every type
127
128
THE GASOLINE AUTOMOBILE
of battery. Alternating current, however, first flows in one direction
and then in the other, the reversals taking place many times per second.
It is the kind of current given out by most of the modern magnetos.
92. Dry Batteries. — The first necessary part of an electric ignition
system is the source of current. For this purpose we can have either
batteries, dynamos, or magnetos. In this chapter only batteries and
battery ignition systems will be discussed. Magnetos will be treated in
the chapter on Magnetos.
The dry battery is a common source of battery current for ignition
purposes. It is comparatively cheap, exceptionally reliable, and can
be easily replaced when worn out. Due to im-
provements in the battery ignition systems its
use for motor car ignition is growing, after hav-
ing given way for a time almost entirely to
magneto ignition. Figure 131 is a section of a
commercial dry cell. It consists of a cylindrical
zinc shell around the inside of which has been
placed a piece of absorbent paper saturated with
a paste made of zinc oxide, zinc chloride, am-
monium chloride, plaster of Paris, and water.
The zinc can forms the negative terminal of the
battery, and the carbon element down through
the center of the cell forms the positive terminal.
The space between the absorbent paper and the
carbon is filled with powdered carbon and
manganese oxide which acts as a depolarizing agent. The voltage of a
dry cell is about 1.5 volts. The maximum possible amperage or current
of a new cell ranges from 20 to 35 amp., depending upon the size of the
cell. The dry battery always gives out direct current. The capacity
and life of a dry cell depends on the way it is used, being greater when
it is used intermittently.
93. Storage Batteries. — Although the storage battery is to be con-
sidered in Chap. VIII on Starting and Lighting Systems, a brief descrip-
tion will be given here in order to bring out clearly its functions in battery
ignition systems. A storage cell, Fig. 132, consists of two sets of metallic
plates placed in a vessel containing a solution of sulphuric acid and
water. In the positive group the plates are lead grids, the openings being
packed with lead peroxide, characterized by its chocolate brown color.
The plates of the negative group consist of finely divided sponge lead.
These sets of plates are placed in the cell so that the positive and negative
plates alternate and are separated by perforated sheets of hard rubber
or specially treated wood. By passing direct current into the top of
one of the plates, through the acid and water, and out the other plate,
FIG. 131.— Section of dry
cell. •
BATTERIES AND BATTERY IGNITION
129
the plates are changed chemically. When the battery is used, the
chemical change is reversed and the plates tend to return to their original
state, giving off current as they do so. The single storage cell of one
positive and one negative set of plates gives, when fully charged, a pres-
sure of about 2 volts and a current depending upon the size and number
of the plates. For ignition purposes the plates are connected so that the
whole battery gives a voltage of from 6 to 8 volts and a capacity of
from 60 to 80 ampere-hours.
Expansion Chamber to
take care of changes in
Volume of Solution '
rluring Charge and Discharge
Soft Rubbct
Casket
Polished Hard
Rubber Cover
Battery Terminal covered
with a layer of pure Para
Rubber vulcanized Directly
to the Corrugated Surface
. of the Conductor to prevent
creeping of acid.
Plates and elements
ofthe l •
.Villard Standard
Faure' Type
Treated Hardwood
Case with Dovetail
joints..
Quadruple .
Plate or Element Supports
of Hard Rubber •
FIG. 132. — Section of Willard storage cell.
94. Series and Parallel Connections. — The voltage of either a dry or
storage cell is not high enough for automobile engine ignition purposes,
and methods of connecting several batteries must be resorted to in order
to raise the voltage and amperage. A voltage of from 6 to 8 is necessary
for an ignition system using an induction coil. This can be obtained
by the connection shown in Fig. 133, in which the carbon of one cell is
connected to the zinc of the next. This is known as the "series" con-
nection. By so connecting the cells, the resultant voltage is equal to
the combined voltage of all, or the number of cells multiplied by the
voltage of one cell, which is 1.5. The current output is equal to the
current of one cell of the given size, or about 20 amp. If all the carbons
are connected and all the zincs fastened together, as shown in Fig. 134,
130 THE GASOLINE AUTOMOBILE
the connection is known as "parallel." The resultant voltage equals
the voltage of one cell and the current output equals the current output
of one cell multiplied by the number of cells. Therefore, to increase
voltage connect the cells in series, and to increase current output con-
nect them in parallel.
5 Dry cells in -series £ Dry cef/s in parallel
FIG. 133. FIG. 134.
95. Battery Connections for Ignition Purposes. — Where the current
demand is small or not continuous, a single series of cells (usually five)
is used. This arrangement is suitable for single cylinder engines, or for
starting engines of two or more cylinders, where a magneto is used after
the engine is in operation.
When the amount of current required is great, the multiple series
connection is used. It is suitable for engines of two or more cylinders and
continuous service. This arrangement
consists of parallel groups of as many
cells in a series as may be required for
the service. Figure 135 shows an arrange-
ment with three parallel sets, each of five
cells connected in series. This arrange-
'•5 cells in multiple series arrangement .
•piQ 13- ment provides for an amperage of about
60 at about 7K volts.
Two series of cells in multiple series connection will have about
three times the life of a single series on the same current, on account of the
reduced rate of discharge. Three series connected in this manner will give
about six times the life on the same current, as would one series.
Another advantage of this method of connection is that a dead cell
will not weaken the current from the group enough to interfere with the
engine operation. For ordinary service, three groups of five cells each
are frequently used, while for heavy, constant service five groups of five
cells each, giving a voltage of about 7.5 and a current of about 100 amp. is
recommended.
96. Simple Battery Ignition System. — The jump-spark or high-tension
system of ignition is so named because a high tension current is caused to
jump across the gap between the terminals of the spark plug in the cylin-
der. Figure 136 shows an elementary battery jump-spark ignition system
for a one-cylinder engine. Four dry cells are shown connected in series
giving a voltage of about 6 and a current of about 20 amp. One terminal
of the battery set is connected to the left terminal of the induction or spark
BATTERIES AND BATTERY IGNITION
131
coil and the other terminal to the engine "timer." The timer, or
commutator, is nothing more or less than a mechanically operated
"switch," placed between the batteries and the right terminal of the coil.
The current from the batteries goes to the left terminal of the coil which is
connected to a standard holding an adjustable contact serew. This
screw is in contact with the vibrator. Passing from the screw into the
vibrator, the current goes through a comparatively large wire wound
around the central core. This wire goes to the right terminal of the coil,
which is connected back to the timer. This circuit forms what is known
as the "primary" of the system. When the timer completes the circuit,
SECONDARY CIRCUIT
JUMP SPARK SYSTEM OF IGNITION
FlG. 136.
current flows through the primary winding. The current flowing around
the iron core makes a magnet of it. This fact causes the vibrator to be
pulled away from the adjusting screw, and this breaks the circuit.
Consequently, current ceases to flow, the core loses its magnetism, the
vibrator flies back to make contact with the screw again, and this
permits the primary current to flow, causing a repetition of events. The
result is a constant dying down and building up of the current in the
primary winding around the core. This results in a dying down and
building up of the magnetism in the core. It will be noticed that there
is another coil of finer wire wound around the primary coil on the iron
core. This is called the "secondary" of the coil. The ends of this
secondary winding are fastened to the two secondary terminals on the top
of the coil. One terminal of the coil is connected to the spark plug in
the cylinder and the other is connected onto the engine frame, or
"grounded."
Each time the current in the primary circuit is broken, there is another
current of very high voltage induced in the secondary winding. This
current is of sufficiently high electrical pressure to jump the spark plug
gap under the usual compression pressure. This voltage varies from
132
THE GASOLINE AUTOMOBILE
10,000 to 20,000 volts. The relation between the voltage on the primary
circuit and that on the secondary depends upon the relative number of
turns of wire on the primary and secondary windings, upon the speed of
the vibrator and the current in the primary winding.
In the bottom of the coil is placed the condenser, consisting of alternate
tinfoil and oiled paper sheets. Every alternate tinfoil sheet is connected
to the bottom of the standard; the ends of the others are connected to the
vibrator. The current tends to continue flowing after the circuit is
broken and, if it were not for this condenser, there would be a fat spark
across the vibrator points every time the circuit was broken. The
condenser prevents this arcing across the vibrator points, when they break,
by absorbing this flow of current and storing it until the circuit is again
closed. In addition, it aids in the induction of the high tension current
in the secondary winding of the coil by permitting the quick break of the
primary current.
The following are the names and functions of the various parts of a
battery ignition system:
Primary Circuit. — That part of the system carrying the battery
^ ^ current at low voltage— a few turns
Primary termindJ
y ^~ ~~^ w*»«i Secondary Circuit.— That part
of the system carrying the high
tension current to the spark plugs
— a great many turns of very fine
wire on the coil.
Timer. — A mechanically oper-
ated switch placed in the primary
circuit. Its function is to com-
plete the primary circuit and cause
the vibrator to act, thus causing
a high tension current to flow to
the spark plugs at the proper
time.
Vibrator. — A spring placed in
the primary circuit to make and
break the current, causing a high
tension current in the secondary.
Condenser. — An electrical ap-
pliance placed in the primary cir-
•Seconcfary terminal
FIG. 137. — Three terminal vibrating
induction coil.
curt to prevent sparking at the vibrator points.
97. The Three Terminal Coil.— Most of the coils used on automobile
ignition systems have only three terminals instead of four. One end
of the primary winding is joined to one end of the secondary and the
BATTERIES AND BATTERY IGNITION
133
junction to one of the terminal binding posts. The other end of the
primary goes to a primary binding post and the other end of the secondary
to the secondary binding post of the coil as shown in Fig. 137. An
FIG. 138. — Pfanstiehl three terminal coil.
SECONDARY WIRES TO PLUGS
PRIMARY WIRES TO TIMER
FIG. 139. — Wiring diagram for four-cylinder engine.
external view of a three-terminal coil for a single-cylinder engine is shown
in Fig. 138. In Fig. 139 a four-unit coil with the wiring for a four-cylinder
engine is shown. The three terminals are lettered: .S, the secondary
terminal leading to the plug; P, the primary terminal to the timer; and B,
134 THE GASOLINE AUTOMOBILE
the terminal connected to the batteries. The secondary circuit is from
the secondary terminal to the plug, across the gap into the engine frame,
back through the timer to the coil. The primary circuit is from the
batteries, one side of which is grounded, through the coil, to the timer,
where the circuit is grounded and the current returns to the batteries
through the metal of the engine.
FIG. 140. — Pfanstiehl four-cylinder coil set.
WIRING DIAGRAM FOR 4-- CYUIND
USINO DRY CEl-l_S
FlG. 141.
Where a multiple cylinder engine is used, it is customary to use
a coil for each cylinder. The coils are usually enclosed in an upright
box as shown in Fig. 140, which is a coil set for a four-cylinder engine.
In Fig. 141 is shown the arrangement of the ignition system for a
BATTERIES AND BATTERY IGNITION
435
four-cylinder engine using dry batteries as the source of current. There
are two sets of batteries, one service set and a reserve set. The six cells
are connected in series, giving a voltage of about 9. The four coils are
placed in one box, with two small terminals at the bottom. Either of
these terminals is a primary terminal for any one of the four coils and is
connected to the two sets of batteries. The switch on the front of the
box determines which set of batteries will be used. The other primary
terminals at the top of the coils are connected to the four binding posts
of the timer. These terminals are also secondary terminals. The large
connections at the bottom of the coil box are secondary wires leading to
the spark plugs. When the timer, which runs at one-half engine speed
or at cam shaft speed, grounds the primary circuit by the roller making
contact with the insulated terminal, a spark occurs in one of the cylinders,
depending upon the position of the roller. Any of the four coils may be
removed from the box for adjustment or repair.
Pull Rod Connection
Case
Thumb Nut
Contact Point
Roller Arm
Brush
Engine Cover
FIG. 142.— The Ford timer.
98. Timers. — Figure 142 shows the timer used on the Ford engine.
The inside or rotating part is fastened to and rotates with the cam shaft.
When the roller comes into contact with one of the terminals on the hous-
ing, the circuit for that coil is closed and a current is caused to flow in
the primary circuit, causing a spark in the secondary circuit. The
housing does not turn with the cam shaft, but can be shifted back and
forth, either advancing or retarding the spark. The timer is always
placed in the primary circuit.
The timers for six- and eight-cylinder engines are similar to the above,
but have six or eight insulated terminals on the housing instead of four.
99. Spark Plugs. — The spark plug consists of two terminals fastened
together, but insulated from each other, and the whole screwed into the
cylinder. The center terminal is insulated from the rest of the plug
and the other terminal. The insulation between the center electrode
and the body of a plug is usually either of porcelain or of mica. The
136 THE GASOLINE AUTOMOBILE
outside terminal is in contact with the engine cylinder and is consequently
grounded. The only way the current can get from one terminal to
another is across the air gap between them. The gap between points
'of the battery spark plugs should be about %2 in., 'or the thickness
FIG. 143. — J. M. soot-proof spark plug.
FIG. 144. — Bosch spark plug.
of a smooth dime. Figure 143 shows the exterior and interior arrange-
ment of the J. M. soot-proof plug. In Fig. 144 is shown the side and
, "— — =— • bottom views of the Bosch plug with three
~~->w grounded electrodes.
100. Master Vibrators. — In order to avoid
the four vibrator adjustments on the four-coil
systems, and the possibility of getting sparks of
different intensity in the different cylinders, a
master vibrator is sometimes used. A master
vibrator is an additional coil with only a primary
winding, one vibrator, and a condenser. It is
placed between the batteries or source of cur-
rent and the primary windings of the coils.
The vibrators of the coils are then screwed down
tight or short-circuited by a copper wire as
shown in Fig. 146. The master vibrator serves
for all four coils and, when once adjusted, the
sparks in all the cylinders will be of the same
intensity. There is only one vibrator to be
adjusted and to get out of order instead of four. The principle of the
master coil is that the winding of the coil and the vibrator are connected
successively in series with the primary windings of each individual coil.
FIG. 145.— Pfanstiehl
master vibrator.
BATTERIES AND BATTERY IGNITION
137
This produces the make and break in the primary winding of the coil.
Figure 145 illustrates the outside view of the Pfanstiehl master vibrator.
Figure 146 shows the application of the K-W master vibrator with both
battery and magneto sources of current.
FIG. 146. — Connections for K-W master vibrator.
101. The High Tension Distributor System. — A typical high tension
distributor system is shown in Fig. 147. This system enables a single
coil to be used to serve a number of cylinders. The particular feature
of this system is the combined low tension timer, or interrupter, and
the high tension or secondary distributor, acting with a single non-
FIG. 147. — High tension distributor system.
vibrating coil. In this particular illustration, two sets of dry cells are
provided, one set being in reserve. The distributor and timer are usually
mounted in a vertical position in a single unit and are driven at cam shaft
speed by a vertical shaft. The coil, as mentioned before, is non-vibrating.
The mechanical contact maker, or interrupter form of timer located
under the high tension distributor, serves in place of the usual vibrator
on the coil.
138
THE GASOLINE AUTOMOBILE
The primary current flows out of the batteries into the bottom
primary terminal of the coil, out of the center primary terminal and over
to the primary binding post on the timer. The revolving contact maker
completes the circuit by grounding the current through the timer shaft.
This contact maker or timer is constructed so as to give a very quick
break to the primary circuit so that there will be a high pressure current
induced in the secondary winding of the coil. This flows out of the
FIG. 148. — Connecticut type E ignition system.
secondary terminal of the coil to the main terminal post of the distributor,
where it is sent to one of the four spark plugs, depending on the position
of the distributor arm. The action of a distributor is much like that of
an ordinary timer used with vibrating coils, though its construction to
handle secondary high tension current is necessarily much different. In-
stead of producing a series of sparks in the cylinder, as is done with the
vibrating coil, the mechanical interrupter produces only one fat spark in
each cylinder.
This arrangement is not so complicated as the multiple coil system.
There is only one adjustment, that at the contact maker, and this insures
sparks of the same intensity in each of the cylinders. The drain on the
batteries is also less, as only one spark is produced in each cylinder, in
contrast to the series of sparks produced by a vibrating coil.
BATTERIES AND BATTERY IGNITION
139
102. The Connecticut Automatic Ignition System. — This system
operates on the high tension distributor principle, using but one coil for
all cylinders. It employs a mechanical interrupter for the primary cur-
rent. Although dry batteries can be used in cases of emergency, the
system is primarily intended for the use of storage batteries as the source
of current. Its ideal use is in conjunction with a generator supplying
current to a storage battery for lighting and starting. Figures 148 and
149 are wiring diagrams showing the connections for the Connecticut
FIG. 149. — Connecticut type G ignition system.
types E and G systems. The essential difference between these systems
is in the switch and coil connections. In type E the coil is integral
with the switch and is designed to be placed under the hood, thus assist-
ing in preserving a clean dash. Type G has a separate switch and coil,
which permits its application where the space is limited, as for instance
when the gasoline tank is carried in the cowl dash. The switch is
mounted on the dash and the coil any place on the engine near the ig-
niter, thus bringing the condenser close to the breaker points and elimi-
nating the necessity of extending the high tension wires to the dash.
140
THE GASOLINE A UTOMOBILE
The combined interrupter and high tension distributor is clearly
shown in Figs. 150, 151, and 152. The interrupter, Fig. 150, first closes
the circuit and permits battery current to flow through the primary
circuit. When one of the lobes on the cam strikes the roller, the circuit
FIG. 150. — Connecticut interrupter.
FIG. 151. — Connecticut igniter with
distributor cap removed.
FIG. 152.— Connecticut igniter
assembled.
^^^•^^^
FIG. 153. — Connecticut type E coil and
switch with cover removed to show
terminal connections.
is opened and a high voltage is thus produced in the secondary winding of
the coil. The high tension current is distributed to the plugs by the
distributor of the instrument. The distributor and interrupter are
BATTERIES AND BATTERY IGNITION
141
mounted in a single unit as shown in Fig. 152, the whole device being
called the igniter.
The igniter is mounted on a vertical shaft running at one-half engine
speed and thus can be mounted the same as the ordinary timer for
vibrating coils. Figure 153 shows the arrangement of the coil terminals.
It will be noted that a spark gap is provided to protect the secondary
winding from the destructive action of the high voltage in case a plug
terminal becomes disconnected so that the high tension current can not
take its regular path. The safety gap is placed in a glass tube inaccessible
to vapor or fumes. It is conveniently arranged for observation in cases
of missing cylinders.
The spark advance and retard in the Connecticut system are effected
by swinging the entire igniter housing either forward or back.
103. The Atwater Kent System. — The Atwater Kent system is also of
the high tension distributor type and has as an optional feature the
CONTACT MAKER
FIG. 154. — Diagram showing principle of Atwater
Kent system.
FIG". 155. — Exterior of
unisparker.
automatic spark advance, which automatically regulates the position of
the spark according to the speed of the engine. This system is designed
to operate in a satisfactory manner with dry cells as the source of current.
The Atwater Kent system consists of two main parts:
(1) The unisparker, which is the contact maker and the distributor
combined in one small case mounted on the timer shaft of the engine.
(2) The coil, which consists of a simple primary and secondary
winding with condenser. The coil has no vibrators or other moving
parts, this function being served by the contact maker. The principle
of the Atwater Kent system is clearly shown in Fig. 154. The battery
current is closed and broken by the mechanical contact maker. The
secondary current from the coil goes to the distributor, where it is
142
THE GASOLINE AUTOMOBILE
directed to the proper plug. The distributor and contact maker are
built together and are called the unisparker.
The unisparker, Type K-2, is illustrated in Fig. 155. It is connected
to the ordinary timer shaft of the engine, the dome-shaped cover con-
taining the primary contact maker and the secondary distributor as
well as the spark advancer. By releasing the two spring clips, the
FIG. 156. — Atwater Kent contact maker.
rubber dome is lifted and the contact maker exposed. The contact maker
of the unisparker is shown in Fig. 156. As will be seen from investigation,
only one spark is produced per explosion stroke, as the circuit is made
and broken but once. An important feature of this contact maker
is that the length of contact is absolutely independent of the engine speed,
and as strong a spark is produced when the engine is cranked by hand as
when the latter runs at normal or even at racing speed. The length of
FIG. 157. — Operation of contact maker.
contact is constant and no greater at any speed than is necessary to
insure the magnetic field of the coil being built up to its full strength.
The action of the contact maker is shown in Fig. 157. The hardened
steel rotating shaft in the center, the lifter, the latch, and the contact
spring are the principal moving parts. The contact is made and broken
by the action of the lifter spring in drawing the lifter back, after it has
BATTERIES AND BATTERY IGNITION
143
become unhooked from the notched shaft. This spring action makes the
speed of the break independent of the speed of the engine. It also makes
the time of contact uniform, and this is adjusted so as to use the least
possible current from the batteries.
Directly above the contact maker
is located the high tension distributor.
This consists of a revolving hard rub-
ber block driven by means of a key
from the end of the operating shaft
and carrying a contact segment on its
circumference. Two, four or six con-
tact pins, depending on the number of
cylinders, are secured into the hard
rubber cover plate of the device, which,
as already stated, forms the body of
the distributor. Proper cable connec-
tions are formed on the terminals of
the cover plate and, from these, connection is made to the individual
spark plugs.
The coil used in connection with the Atwater Kent system consists of
simple primary and secondary windings of generous proportions, which,
FIG. 158. — Atwater Kent kick
switch coil.
Motor stopped or running slowly. Motor at high speed.
FIG. 159. — Atwater Kent automatic spark advance mechanism.
together with a condenser, are sealed into a container. There are no
moving parts or adjustments.
One of three types of coils is usually furnished with the Atwater
Kent system: a simple plate switch coil, a kick switch coil, shown in Fig.
158, or an underhood coil with separate switch. Both plate and kick
15
144
THE GASOLINE AUTOMOBILE
switches are provided with a push button for producing starting sparks
without cranking.
Automatic Spark Advance.— -Figure 159 shows the centrifugal gov-
ernor which advances the spark as the speed increases. The rotating
shaft is divided, and as the governor weights expand they rotate the
upper part of the shaft forward in its own direction of rotation, thus
making and breaking contact earlier than at slow speed.
In Fig. 160 the wiring diagram of the Atwater Kent installation is
shown. Among the particular features of this system are: time of
closed primary circuit is independent of engine speed; speed of break is
independent of engine speed; circuit cannot be closed when engine is
stopped; battery consumption is reduced to a minimum; the spark is
uniform in all cylinders and is independent of engine speed.
FIG. 160. — Atwater Kent wiring diagram.
104. The Westinghouse Ignition System. — There are several igni-
tion systems made, particularly for cars equipped for electric starting
and lighting, in which the source of current is a storage battery kept
charged at all times by the starting and lighting generator. In some,
the generator simply keeps the battery charged and the ignition system
is entirely separate but draws its current from the battery. In others,
the generator carries the interrupter and the high tension distributor for
the purpose of timing and distributing the current.
The Westinghouse system of ignition is mounted as a unit with the
electric generator which supplies electric current to the storage battery
for lighting or starting or both. When the engine is not running or is
operating at very low speed, the ignition current is supplied entirely by
the battery. After the engine reaches a certain speed, the current may
be supplied in whole or in part by the generator.
The ignition outfit consists, in addition to the generator and storage
battery, of an ignition switch and coil on the dash, and an interrupter
and distributor which are made a part of the generator. The ignition
coil transforms the voltage of the battery up to the high tension required
for the spark plugs. The interrupter closes and then opens the ignition
circuit at each half revolution of the generator shaft, and the distributor
BATTERIES AND BATTERY IGNITION
145
directs the high tension current to each of the spark plugs in succession.
Figure 161 shows the exterior of the generator with the distributor and
interrupter on the right hand end.
FIG. 161. — Westinghouse ignition and lighting generator.
The view of the generator disassembled, Fig. 162, shows the principal
parts. This system has an automatic spark advance operated by
centrifugal weights inside the interrupter.
FIG. 162. — Parts of Westinghouse ignition and lighting generator.
Figure 163 illustrates the interrupter with the centrifugal weights
and springs in the position they occupy when the engine is at rest.
Figure 164 shows the position that the weights occupy when the
engine is running at high speed.
The operation of the ignition system, including the interrupter and
146 THE GASOLINE AUTOMOBILE
distributor, ignition coil and switch, begins with the "making" of the
primary circuit of the coil when the centrifugal weights push down the
FIG. 163. — Westinghouse generator with distributor and interrupter cover removed.
fiber bumper, forcing the interrupter contacts to close. Then the
weight moves off the fiber bumper, allowing the contacts to suddenly
separate or open. This break of the
primary circuit induces a high voltage
in the secondary of the ignition coil.
This is led to the distributor, which di-
rects it to the proper spark plug, caus-
ing a spark at the spark plug gap. As
the speed of the engine increases, the
weights are thrown out from the center
and automatically advance the time of
closing or opening the interrupter con-
FIG. 164. — Westinghouse in- tacts, and hence advance the spark. At
the Same time> due to their shaP6> ^
keep the contacts closed during a longer
period of the revolution when running at high speed; this makes the
BATTERIES AND BATTERY IGNITION
147
length of time of contact practically the same at all speeds and prevents
the spark voltage from falling off at high speeds.
In generators not provided with automatic spark advance the cen-
trifugal weights are omitted and a solid cam substituted. The interrupter
contacts are changed so as to make the breaking of the contact occur
when the lever is pushed down by the cam instead of when being
returned by the spring.
105. The Delco System of Ignition. — All the Delco systems are not
identical, there being slight changes to adapt them to the different cars.
For example, the ignition coil on some cars is mounted on the dash, or
on top of the starting motor-generator instead of on the side, as shown
in Fig. 165.
All current for lights, horn, and ignition is supplied first to the com-
bination switch, and after passing through the protective circuit breaker
FIG. 165. — Delco ignition system.
on the dash is distributed to these different units. When the generator
is supplying the current, it comes from the forward terminal on the side
of the generator through the wire A to the switch. The storage battery
current is connected through the wire B. If the button B is pulled out,
the current from the dry cells is used for ignition. If button M is pulled,
the current will be taken either from the generator or storage battery,
depending on whether or not the generator is in operation. Thus, either
the M or B button may be used for starting.
The excess current from the generator flows through the wire B to
the storage battery. An ammeter inserted in the line A would indicate
the amount of current coming from the storage battery to the generator
when the engine is not running, or it would indicate the current being
generated when the engine is running.
Distributor and Timer. — The distributor and timer is carried on the
148 THE GASOLINE A UTOMOBILE
front of the motor-generator, and is driven through a set of spiral gears
attached to the armature shaft. The distributor consists of a cap or
head of insulating material, carrying one high tension contact in the
center, with similar contacts spaced equidistant about the center, and
a rotor which maintains constant communication with the central
contact. The rotor carries a contact button which serves to close
the secondary circuit to the spark plug in the proper cylinder.
Beneath the distributor head and its rotor is the timer, a diagram
of which is shown in Fig. 166. This is provided with a screw A in the
center of the shaft, the loosening of which allows the cam to be turned in
either direction to secure the proper timing, turning in a clockwise direc-
tion to advance and counter-clockwise to retard. The spark occurs at
the instant the timer contacts are opened.
FIG. 166.— The Delco timer.
A weight on the timer shaft acts as a centrifugal governor to operate
the automatic spark control. In addition to the automatic spark con-
trol a manual control is provided, which is operated by a lever on the
steering column, and is connected to the lever at the bottom of the motor
generator. The manual spark control is for the purpose of securing the
proper ignition control for variable conditions such as starting, differences
in gasoline, and weather conditions. The automatic control is for the
purpose of securing the proper ignition control necessary for the varia-
tions due to speed alone.
The Coil. — The ignition coil is the dark vertical cylinder shown on the
front side of the motor generator in Fig. 165. It serves to transform
the low voltage current in the primary circuit to a current of high voltage
in the secondary circuit. The coil consists of a primary winding of
coarse wire wound around an iron core in comparatively few turns, and
of a secondary winding of many turns of fine wire, also the necessary
insulation and terminals for wiring connections.
BATTERIES AND BATTERY IGNITION
149
106. The Remy-Studebaker Ignition System. — This system, shown
in Fig. 167, is built by the Remy Electric Co. and is used on the Stude-
baker car. It is of the high tension distributor type with the primary
current furnished by the storage battery. Dry batteries are supplied for
emergency purposes. The storage battery is kept charged by the starting
generator. The distributor and breaker box form an individual unit,
as shown in Figs. 168 and 169. Figure 169 shows clearly the operation
of a distributor, the current entering at the center and being directed by
TO O
TO P
FIG. 167. — Wiring diagram of Remy-Studebaker ignition system.
the revolving arm to the different contact plates on the inside of the cover.
These connect to the different plugs.
The transformer coil is of the non-vibrating type furnishing a single
spark, the interruption of the primary circuit taking place in the breaker
box. Inside the breaker box is the primary interrupter or circuit breaker.
By the action of the cam D the two points A and B close and open twice
in each revolution of the shaft. These points are in the circuit of the
current flowing from the battery to the primary coil winding. The
interruption of this current induces a high tension current in the secondary
winding of the coil. The interrupter makes two sparks to one revolution
of its shaft and therefore must run at twice the speed of the distributor
150
THE GASOLINE AUTOMOBILE
FIG. 168. — Face and side views of Remy-Studebaker distributor and breaker box.
BREAKER BOX
COVER 0
BREAKER
BOX N
D
FIG. 169. — Remy-Studebaker igniter disassembled.
BATTERIES AND BATTERY IGNITION
151
for a four-cylinder engine. For six cylinders it would make three revolu-
tions to one of the distributor.
107. Spark Advance and Retard.— It is very essential in a variable
speed gasoline engine that the time at which the spark occurs in the cylinder
be changed according to the engine speed, as it takes a certain length of
time to produce an explosion, regardless of the engine speed. When the
engine speed is high, the spark must occur before the piston reaches dead
center in order to have the full force of the explosion when the piston has
just passed the center position. When the engine speed is slower, the
spark can occur later and yet have the force of the explosion exerted
just after dead center. It is necessary when starting that the spark occur
not before dead center.
These various considerations de-
mand that the position of the spark
be made variable. This is usually
done by shifting the timer, or inter-
rupter housing, causing the break of
the primary current (and conse-
quently the spark in the cylinder)
to occur earlier or later. The posi-
tion of the spark is in most cases
governed from the steering column.
In starting the engine, the spark
should not occur until after the pis-
ton has started on its down stroke.
It should then be advanced as the
engine increases its speed. If the
spark is too far advanced there will
be a decided knock in the cylinders.
108. Automatic Spark Advance. — In several modern ignition systems,
means are provided by which the position of the spark is automatically
advanced and retarded. This relieves the driver from the responsibility
and uncertainty of correctly gauging the position at which to set the spark
lever. Figure 170 shows the Delco spark advance mechanism used on
the Cadillac. As is seen, it consists of a ring governor which determines
just when the timer contact breaks. As the engine speeds up, the ring
swings nearer to a horizontal position and this shifts the interrupter cam
so that the circuit is broken earlier. A spring pulls them back when the
engine slows down. The mechanism of the Atwater Kent automatic
spark advance was shown in Fig. 159 and that of the Westinghouse system
in Figs. 163 and 164.
FIG. 170.- — Delco automatic spark
advance mechanism as used on Cadillac
cars.
CHAPTER VII
MAGNETOS AND MAGNETO IGNITION
109. Principles of Magnetism. — The principle upon which a magneto
is constructed involves an understanding of some elementary magnetic
and electrical principles in addition to those discussed in the preceding
chapter.
Magnets. — It is a well known fact that either in a bar magnet or in a
magnet bent in the shape of a horseshoe, as in Fig. 171 the "magnetism,"
that invisible force which attracts and repels iron or steel, is concentrated
near the ends, as indicated by the bunches of iron filings at the ends of
these magnets. One end of the magnet is called the "north" or N-pole,
FIG. 171.
and the other the "south" or S-pole. The difference between the two
poles can be seen by taking two horseshoe magnets and placing their like
poles and again their unlike poles together. It will be found that the
"like" poles repel each other and the "unlike" poles attract each other,
This is the fundamental law of magnetism.
Lines of Force. — If a horseshoe magnet be placed on its side, as shown
in Fig. 172, a piece of paper put over it, and iron filings be sprinkled over
the paper, we shall find that the filings arrange themselves in well-
defined lines, their direction being as indicated. This arrangement
shows us that there is a magnetic force acting between the two poles of
153
17
154 THE GASOLINE AUTOMOBILE
the magnet. The direction is shown and, if the investigation be con-
tinued, it will be discovered that this invisible force acts from north pole
to south pole. These invisible lines are known as magnetic "lines of
force."
Permanent and Electro+magnets. — Horseshoe magnets are either
"permanent" or "electro" magnets. A permanent magnet is one
FIG. 172.
made of highly tempered steel which has been magnetized and usually
retains its magnetism indefinitely. An electro-magnet, Fig. 173, is made
of wrought iron or soft steel, and carries a coil of wire through which a
current of electricity is passed when the iron or steel is to become mag-
netized. As soon as the current in the wire is cut off, the magnet loses
its magnetism. The name "electro-magnet" signifies that the mag-
FIG. 173. — Electro-magnet. FIG. 174. — Simple magnet. Compound magnet.
netism is the effect of the electric current. In the mechanical generation
of current we shall see that the magnetism in the horseshoe magnet is
made use of. If a permanent magnet is used for creating the magnetic
field, the machine is called a "magneto" and if electro-magnets are
used, the machine is called an electric generator.
MAGNETOS AND MAGNETO IGNITION
155
•Magnets
Simple and Compound Magnets. — In some types of magnetos, com-
pound permanent magnets are used. A compound magnet is one built
up of several simple magnets, as shown in Fig. 174. It has been found
that a compound magnet is much stronger than a simple magnet of the
same size.
110. Mechanical Generation of Current. — It is found that if a wire
be moved across the magnetic field be-
tween the poles of a magnet so as to
cut the "lines of force" there will be
an electric current generated in the
wire. If the wire should now be moved
across the lines of force in the opposite
direction, the current will also flow in
the opposite direction in the wire. The
reason for this is not clearly explained,
but it is a well known fact that cutting
magnetic lines of force by moving a
wire across them will generate current
in the wire.
Pole pieces
Rotating armature
FIG. 175.
This fact is made use of in the mag-
neto, an elementary type of which is
shown in Fig. 175. The wire has been formed in the shape of a rect-
angle and arranged to rotate between the pole pieces of the magnet.
If the ends of the wire are connected by a measuring instrument, a current
of electricity will be found to flow out of one end of the wire and into
the other end as the wire is revolved. This current will be an alternating
current; that is, the current changes in direction each time the rectangle
FIG. 176.
turns over. When the wire is cutting the "lines of force" at right angles
the voltage is the maximum, and it is at this period of rotation that the
current is best for ignition purposes. This condition occurs twice during
a complete revolution of the loop of wire.
In an actual magneto, instead of having only one turn of wire, a
156 THE GASOLINE AUTOMOBILE
great many turns of wire are wound in the shape of a coil around a piece
of laminated iron, called the armature core. This coil is caused to rotate
between the magnetic poles, generating a current in it. Figure 176
illustrates the change and cutting of the magnetic lines of force during
one complete revolution of the armature. By using the laminated
iron armature core, the flow of the magnetism between the poles of the
magnet is increased, thus increasing the lines of force that are cut by the
coils of wire.
111. Low and High Tension Magnetos. — A "low tension" type of
magneto is one which delivers current of a low voltage, which must be
converted to the necessary high voltage for ignition by an external
transformer coil. The armature contains only a primary winding,
while the transformer coil has the usual primary and secondary windings.
FIG. 177. — Side view — Remy Model P magneto.
A "high tension" magneto delivers current from the armature of
sufficiently high voltage for ignition, without the use of an external
transformer coil. The high tension current is generated by having two
windings on the armature of the magneto, one a primary winding, and
the other a secondary winding. The armature assembly also contains a
condenser. The true high tension magneto must not be confused with
the so-called high tension magnetos in which the armature current
is transformed by a coil merely placed in the top of the magneto, instead
of outside as is done in the low tension type. The coil is merely con-
tained in the magneto assembly for convenience but this does not make
it a "high tension" magneto in the strict sense of the term.
112. Armature and Inductor Types. — :An "armature" type of
magneto is one in which the lines of force are cut by means of a coil of
MAGNETOS AND MAGNETO IGNITION
157
wire wound on an armature rotating between the magnetic pole pieces,
as just described. It may be either of the high or low tension type.
In an "inductor" type of magneto, the coil of wire is stationary.
The cutting of the lines of force by the stationary coil is caused by a
revolving "inductor." The current is generated in the stationary coil
and this avoids the necessity of having sliding contacts and brushes in
order to connect the coil with the external circuit. The inductor type
may also be "low" or "high" tension. The constructional features
of these two general types will be pointed out in considering the several
modern magneto types.
FIG. 178. — Distributor end view — Remy Model P magneto.
113. Remy Model P Magneto. — Figures 177 and 178 show side
and distributor end views of the Remy Model P magneto, of the low
tension armature type.
The Remy armature shown in Fig. 179 is of the H or shuttle type,
with laminated core made from soft Norway iron. The armature heads
are of hard bronze, and the drive shaft, which is of steel, is cast into the
armature head. The armature winding is of cotton covered enameled
wire heavily impregnated with a special insulating compound rendering
it impervious to heat and moisture. The armature shaft revolves on
158 THE GASOLINE AUTOMOBILE
magneto-type ball bearings which are made dust and grit proof by the
use of felt washers.
In a low tension magneto, the current generated in the armature is led
through a circuit breaker to the primary winding of the coil. When the
circuit breaker is closed, the current flows through the primary winding
and magnetizes the core of the coil. At the desired instant for the
spark, the circuit breaker opens the circuit quickly and thus destroys the
magnetism of the core of the coil. This action induces a high tension
current in the secondary winding of the coil. This is led back to the
distributor of the magneto, where it is directed to the proper spark plug
on the engine.
The armature winding cuts the lines of force twice in each revolution
and therefore will give two sparks per revolution. For this reason, there
are two lobes on the cam which operates the circuit breaker. For a four-
cylinder engine, the magneto armature should run at crank shaft speed,
as two sparks are required per revolution of the engine. For a six-
cylinder engine, the armature of the magneto should run at one and one-
half times crank shaft speed, as three sparks are needed per revolution of
the engine. The distributor" terminals should be connected to the plugs
in the order in which the cylinders are to fire.
The Circuit Breaker. — The circuit breaker illustrated in Fig. 180 may
be shifted by the spark lever to change the time of the spark. The
breaker points are made of iridium-platinum, which gives them an
exceedingly long life. The timing control lever may be located on either
side of the magneto, as the circuit breaker and housing are reversible.
An ample timing range of 35° is provided for.
Condenser. — The condenser, instead of being placed in the coil, is
placed just above the armature. The purpose of the condenser is to
prevent sparking at the breaker points, when they break the magneto
primary circuit.
Magnets. — The magnets are made from tungsten-steel specially
heat treated and hardened, thereby insuring the retention of magnetism
for a long period.
Coil. — The coil, the top view of which is seen in the wiring diagram of
Fig. 181, has the switch built integral with it. The coil is fastened
behind the dash and the switch face only appears on the driving side.
Distributor and Timing Button. — The distributor terminals located on
the face of the distributor provide a reliable method of securing the high
tension spark plug cables. An ingenious device, known as the timing
button, is incorporated in the distributor, for the purpose of timing the
magneto to the motor. With this device the circuit breaker and dis-
tributor are brought into proper position, thus facilitating this usually
difficult operation of timing the magneto to the motor, an operation that
frequently puzzles even an experienced repair man.
MAGNETOS AND MAGNETO IGNITION
159
FIG. 179. — Armature of Remy Model P magneto.
FIG. 180. — Remy Model P magneto — circuit breaker removed.
FIG. 181. — Wiring diagram for Remy Model P magneto.
160 THE GASOLINE AUTOMOBILE
For timing the magneto, turn the engine over by the starting crank
until No. 1 piston reaches the top dead center at the end of the com-
pression stroke. Press in on the timing button at the top of the dis-
tributor and turn the magneto shaft until the plunger of the timing
button is felt to drop into the recess on the distributor gear. This places
both distributor and circuit breaker in the proper position correspond-
ing to the engine position given above, and they may now be coupled
together.
114. The Connecticut Magneto. — This magneto, illustrated in Fig.
182, likewise has a shuttle wound armature revolving between the
poles of permanent magnets, and generates an alternating low ten-
sion current with two impulses for each revolution. It has but a single
FIG. 182. — Connecticut magneto partially disassembled.
primary wire running to the switch; all secondary wires connect from
the magneto direct to the plugs. The transformer coil is encased in
a metal tube in cartridge form and is mounted in the magneto just above
the armature.
115. Dual Ignition Systems. — The voltage generated in a magneto
depends on its speed, and this makes it desirable to have some other
source of current for starting an engine. This auxiliary source is either
a set of dry cells or a storage battery. In the dual system the battery
supplies the primary current for starting, the current being led through
the circuit breaker and primary winding of the coil. On the dual system
the regular coil and distributor of the magneto are used. After the engine
is started the switch can be thrown to use the magneto current.
MAGNETOS AND MAGNETO IGNITION
161
116. Eisemann High Tension Dual Ignition. — The wiring diagram
for the Eisemann E. M. Dual system is shown in Fig. 183. This magneto
is of the high tension armature type. The Eisemann dual system consists
of a direct high tension magneto and a combined transformer coil and
switch, the transformer being used only in connection with the battery,
and the switch being used in common by both battery and magneto systems.
The magneto is practically the same as a single ignition high tension
instrument. To insure reliability, the vulnerable parts of each system
are separate from those of the other. For instance, separate windings
and circuit breakers are used for each system. On the other hand, parts
FIG. 183. — Wiring diagram — Eisemann type E. M. Dual four-cylinder ignition
system.
that are not subject to accident or rapid wear are used in common, so as
to avoid unnecessary duplication.
The magneto armature is an iron core, made of many pieces of soft
sheet iron riveted together, around which is a primary winding of medium-
gauge copper wire. Over this primary winding, is a secondary winding
consisting of many coils of very fine copper wire, the wire being specially
insulated in the entire length and the layers being carefully insulated
from each other. The low tension current, formed by rotating the arma-
ture, in turn induces a secondary or high tension current in the secondary
winding. The transformation of the low tension current into high ten-
sion current is obtained by suddenly interrupting the low tension current
162
THE GASOLINE AUTOMOBILE
by the circuit breaker or make-and-break mechanism . It will thus be seen
that the high tension armature is practically a transformer coil wound
directly on the armature core with a circuit breaker to interrupt the
primary current.
Spark Control— As the spark occurs when the primary circuit is
broken by the opening of the platinum contacts, the timing of the spark
can, therefore, be controlled by having these platinum contacts open
sooner or later. This latter is accomplished by the angular movement of
the timing lever body. This movement gives a timing range of 30°.
The spark is fully retarded when the timing lever is pushed as far as
possible in the direction of rotation of the armature and is advanced
when pushed in the opposite direction.
Safety Spark Gap. — If a spark plug cable becomes disconnected or
broken, or should the gap in the spark plug be too great, then the second-
ary current has no path open to it and, in endeavoring to find a circuit,
FIG. 184. — Eisemann armature with automatic spark advance mechanism.
will sometimes puncture the insulation of the armature or of the coil.
To obviate this, a so-called "safety spark gap" is placed on the top of
the armature dust cover. It consists of projections of brass with a gap
between. them. One of these is an integral part of the dust cover, and
therefore forms a ground.
The Coil. — The coil of Fig. 183 is designated as Type D C and consists
of a non-vibrating transformer and a switch which is used in common
to put either the battery or magneto ignition into operation. The coil
is cylindrical in shape, is compact, and is placed through the dashboard.
The end which projects through on the same side as the motor has.
terminal connections for the tables. The other end, facing the operator,
contains the switch and the starting mechanism. The transformer coil
is used only in conjunction with the battery. There is a push button
circuit breaker in the center of the switch for producing a spark with
the battery current when the engine is not running. The coil is provided
with a lock and key, so that the switch may be locked in the "off"
position.
MAGNETOS AND MAGNETO IGNITION 163
117. Eisemann Automatic Spark Control. — The automatic spark
control magneto is of the same construction as the standard high-tension
instrument with the addition of the automatic mechanism as shown in
Fig. 184. The automatic advance is accomplished by the action of
centrifugal force on a pair of weights attached to one end of a spiral
sleeve between the shaft of the magneto and the armature. When the
armature is rotated, the weights begin to spread and exert a longitudinal
pull on the sleeve, which in turn changes the position of the armature
with reference to the pole pieces, In this way, the moment of greatest
induction is advanced or retarded and with it the break in the primary
circuit. The cams which lift the circuit breaker and cause the break in
the primary circuit are fixed in the correct position with relation to the
armature, so that the break occurs at the moment when the current in
the winding is strongest.
118. The K-W High Tension Magneto.— The K-W high tension
magneto is of the alternating current inductor type. Figure 185 is an
external view and Fig. 186 shows a longitudinal sectional elevation. By
referring to the numbers, an idea can be obtained of the function of the
various parts.
64 Driving pinion. 1 Bridge.
79 Plunger for primary circuit. 100 High tension lead.
67 Cam. 96 Distributor block.
68 Cam roller. 73 Magnets.
189 Retainer spring. 180 Rotor.
56 Switch binding post. 114 Primary winding.
98 Distributor brush holder. 113 Secondary winding.
120 Secondary contact plunger. 126 Condenser.
119 Secondary distributor 118 Safety spark gap.
plunger. 186 High tension bus bar.
2 Distributor gear. 14 Low tension bus bar.
10 Base.
The only revolving part in the K-W magneto is shown in Fig. 187.
This part is the rotor which is constructed of fine laminations of the
softest Norway sheet iron. These laminations are riveted together,
are accurately bored out to fit the rotor shaft, and are accurately ma-
chined as to width and diameter, being mounted on this shaft at exactly
right angles to each other. Between these two pieces is the stationary
winding or coils, also shown separately in Fig. 188. The winding, which
is concentric with the armature shaft, is mounted in between the two
halves of the rotor and stands absolutely still. In the position shown,
the lines of force go straight across through the right hand rotor. When
the shaft turns 45° from this position, the rotors connect the magnetism
from one pole piece, through the center of the winding, to the opposite
pole piece, thus giving a powerful wave of current from a quarter revolu-
tion of the magneto.
164 THE GASOLINE AUTOMOBILE
The winding, shown in Fig. 188, is a double winding, that is, it has a
primary or low tension winding, which is surrounded by a secondary or
high tension winding. This primary winding goes to the circuit breaker
of the magneto, where its current is interrupted when the spark is
FIG. 185. — K-W high tension magneto.
/0
FIG. 186. — Section of K-W magneto.
wanted and during one of the periods of armature rotation in which con-
siderable current is generated.
At the moment of this interruption of current in the primary, a power-
ful surge of current is generated in the secondary winding. The current
from this secondary winding goes straight up through the hard rubber
terminal to the high tension bus bar, as shown in Fig. 186, to the center
MAGNETOS AND MAGNETO IGNITION
165
of the distributing brush* and from there is distributed to the various
cylinders of the motor.
The condenser, No. 126, Fig. 186, is bridged across the circuit breaker
points. Its function is to absorb the low tension current after the
FIG. 187.— K-W rotor and coils
FIG. 189. — Wiring diagram for K-W high tension magneto.
breaking of the primary circuit at the breaker points. This condenser
is made of a large number of sheets of tinfoil and mica.
166
THE GASOLINE AUTOMOBILE
The safety gap, No. 118, Fig. 186, is a necessary part of any high tension
magneto, its object being to form a path for the high tension current to
jump through incase a secondary cable that leads to the spark plugs
should be off when the engine is running. This safety gap, as its name
implies, prevents the magneto from burning out, for as long as there is a
path for the high tension current to pass through, it will never punc-
ture the insulation of the secondary winding.
It will be noted by referring to Fig. 186 that the distributor shaft is
carried on two ball bearings, as is also the rotor shaft. The distributor
block is moulded from a special composition of hard rubber, and is ac-
curately machined all over. The brass segments that connect with the
various plug holes on top of the distributor are moulded into the hard
FIG. 190. — Dixie magnets and rotor. FIG. 191. — Dixie coil and field pieces.
rubber. A carbon brush is mounted in the distributor arm, which presses
slightly against the distributor segments, and the interior of the distributor
is practically dust and moisture proof, being protected by a hard rubber
cover, held in place by a three-legged spider or bridge, No. 1 . This bridge
also carries the primary circuit to the circuit breaker. The binding
post, No. 56, is the point from which the switch wire is run to the switch
for the purpose of cutting out the circuit breaker and stopping the engine.
Figure 189 is a wiring diagram for the K-W high tension magneto,
Type H.
119. The Dixie Magneto. — The Dixie magneto is built upon a princi-
ple different from that of either the armature or the inductor types.
Figure 190 indicates the arrangement of the magnets and the rotating
element carried in bearings by the two pole pieces. This rotor turns
MAGNETOS AND MAGNETO IGNITION
167
between the pole pieces and, as the iron pieces simply form extensions
to the magnet pole pieces and are always of the same polarity, there is
no reversal of magnetism through them.
Just above the rotor, and with its axis at right angles, is placed the
coil, supported by the two upright field pieces enclosing the armature as
shown in Fig. 191. Figures 192, 193, 194, and 195 show the reversal of the
FIG. 192. FIG. 193. FIG. 194. FIG. 195.
FIGS. 192 TO 195. — Showing the principle of the Dixie magneto.
lines of force through the coil during one-half revolution of the rotor.
This change of the lines of force through the coil, which has a primary and
a secondary winding, causes a low tension alternating current in the
primary winding, and this induces the high tension current in the secondary
winding when the contact points break the primary circuit. Figure 196
is a diagrammatic sketch of the primary circuit. P is the primary coil, A
FIG. 196. — Primary circuit of Dixie magneto.
FIG. 197. — Bosch high tension
magneto.
is the core, R is the condenser, X and Y are the circuit breaker points, G
is the common ground connection for both primary and secondary wind-
ings, and S is the secondary coil.
120. The Bosch High Tension Magneto.— The Bosch magneto,
shown in Fig. 197, is of the high tension armature type, generating two
sparks during each revolution of the armature shaft. A longitudinal
168 THE GASOLINE AUTOMOBILE
section of a Bosch magneto is shown in Fig. 198 and a rear view in Fig.
199. The principal numbered parts are as follows:
1 Brass plate at the end of the primary winding.
2 Fastening screw for contact breaker.
119 Long platinum contact screw.
118 Short platinum contact screw.
9 Condenser.
120 Lock nut for contact screw 119.
121 Flat spring for magneto interrupter lever.
105 Holding spring for interrupter cover.
10 High tension collector ring.
11 Carbon brush for high tension current.
12 Holder for brush.
13 Fastening nut for brush holder.
FIG. 198. — Section of Bosch high tension magneto.
14 Spring contact for conducting the high tension current.
15 Distributor brush holder.
16 Distributor carbon brush.
17 Distributor disc.
18 Central distributor segment.
20 High tension terminals.
22 Dust cover. .
123 Interrupter lever.
168 Interrupter housing and timing lever.
169 Cover for interrupter housing.
173. Low tension brush.
The beginning of the primary winding is grounded to the armature
core and the other end is connected to the brass plate 1. In the center
of this plate is the fastening screw 2, which serves first, for holding the
contact breaker in its place, and second, for conducting the primary cur-
rent to the platinum screw block of the contact breaker. Screw 2 is insu-
MAGNETOS AND MAGNETO IGNITION
169
lated from the contact breaker disc, which is in metallic connection with the
armature core. The platinum screw 119 is fixed in the contact piece
and receives the current from screw 2. Pressed against this platinum
screw, by means of the spring shown, is the magneto interrupter lever 123
with platinum screw 118, which is connected to the armature core and,
therefore, with the grounded end of the primary winding. The primary
circuit is, therefore, closed as long as the magneto interrupter lever 123
is in contact with platinum screw 119. The circuit is interrupted when
the lever is rocked by the cam so as to open the contact. The condenser
9 is connected across the gap formed when the contacts break.
The beginning of the secondary winding is connected to the insulated
end of the primary so that the one forms a continuation of the other.
The other end of the secondary winding leads to the collector ring 10,
20
20
FIG. 199. — End view of Bosch high tension magneto.
on which slides a carbon brush 11, held by the carbon holder 12, and thus
insulated from the magneto frame. From the brush 11 the secondary
current is conducted to the terminal 13, through the spring connection
14 to the center distributor contact 18, and from there to the carbon
brush 16, the latter rotating with the distributor gear wheel.
In the distributor disc 17, metal segments are embedded, and as the
carbon brush 16 rotates, it makes contact with the respective segments of
the distributor. Attached to the metal segments of the distributor are
the connection terminals 20 to which are fixed the conducting cables to the
spark plugs.
From the end of the secondary winding the high tension current is
distributed to the respective cylinders in the order in which they operate.
The current produces the spark which causes the explosion; it then
returns through the motor frame and the armature core back to the be-
18
170
THE GASOLINE AUTOMOBILE
ginning of the secondary winding. The diagram of connections is shown
in Fig. 200.
Safety Spark Gap. — In order to protect the insulation of the armature
and of the current conducting parts of the apparatus against excessive
voltage, a safety spark gap is provided as shown in Fig. 200. The current
will pass through this gap in case a cable is taken off while the magneto
is in operation or if the electrodes on the spark plugs are too far apart.
The discharges, however, should not be allowed to pass through the
safety gap for any length of time; special care has to be taken in this
respect if the motor is equipped with a second system of ignition, in
INTERRUPIOfl MS
» FIG. 200. — Wiring diagram of Bosch high tension magneto.
which case it is necessary to short circuit the primary winding, as the
continued discharge of the current over the safety gap is likely to damage
the magneto.
121. The Bosch Dual System.— In the Bosch dual ignition system,
the standard type of Bosch magneto is used with the application of two
timers or interrupters. The parts of the regular current interrupter are
carried on a disc that is attached to the armature and revolves with it,
the rollers or segments that serve as cams being supported on the inter-
rupter housing. In addition, the magneto is provided with a steel cam
which is built into the interrupter disc and has two projections. This
cam acts on a lever supported by the interrupter housing, the lever
3emg so connected in the battery circuit that it serves as a timer to
control the flow of battery current. These parts may be seen in Fig.
MAGNETOS AND MAGNETO IGNITION
171
-HIGH TENSION CONNECTION
FIG. 201. — Bosch dual system, showing magneto interrupter and battery timer.
FIG. 202. — Wiring diagram for Bosch dual system.
172 THE GASOLINE AUTOMOBILE
201. A non-vibrating transformer coil is used with the battery current
to produce the necessary voltage.
It is obvious that the sparking current from the battery and from
the magneto can not be led to the spark plugs at the same time, so a
further change from the magneto of the independent form is found in
the removal of the direct connection between the collecting ring and
the distributor. The collecting ring brush shown in Fig. 198 as No. 11
and in Fig. 202 as No. 3, is instead, connected to the switch, and a second
wire leads from the switch to the central terminal on the distributor.
When running on the magneto, the sparking current that is induced in
the secondary armature winding flows to the distributor by way of the
switch contacts. When running on the battery, the primary circuit of
the magneto is grounded, and there is, therefore, no production of spark-
ing current by the magneto; it is then the sparking current from the
Fio. 203.— Parts of Bosch dual coil.
coil that flows to the central distributor connection. It will thus be
seen that of the magneto and battery circuits the only parts used in
common are the distributor and the spark plugs.
The Bosch Dual Coil. — The Bosch dual coil used in the dual system
consists of a cylindrical housing bearing a brass casting, the flange of
which serves to attach the coil to a dashboard or other part. The coil
is provided with a key and lock, by which the switch may be locked when
in the " Off" position. This is a point of great advantage, for it makes it
unlikely that the switch will be left thrown to the battery position when
the engine is brought to a stop. The absence of such an attachment is
responsible in a large measure for the accidental running down of the
battery. This locking device also prevents the unauthorized operation
of the engine. The parts of the coil are shown in Fig. 203. In addition
MAGNETOS AND MAGNETO IGNITION 173
to the housing and end plate, they consist of the coil itself, the stationary
switch plate, and the connection protector.
When the engine is running on battery ignition, a single contact
spark is secured at the instant when the battery interrupter breaks
its circuit, and the intensity of this spark permits efficient operation of
the engine on the battery system.
Starting on the Spark. — For the purpose of starting on the spark, a
vibrator may be cut into the coil circuit by turning the button that is
seen on the coil body in Figs. 202 and 203. Normally, this vibrator
is out of circuit, but the turning of the button places it in the battery
primary circuit instead of the circuit breaker on the magneto. A
vibrator spark of high frequency is thus produced.
It will be found that the distributor on the magneto is then in such
a position that this vibrator spark is produced at the spark plug of the
cylinder that is performing the power stroke; if mixture is present in
this cylinder, ignition will result and the engine will start.
Connections. — In the wiring diagram of this system as shown in Fig.
202, it will be noted that while the independent magneto requires but one
switch wire in addition to the cables between the distributor and spark
plugs, the dual system requires four connections between the magneto
and the switch; two of these are high tension and consist of wire No. 3
by which the high tension current from the magneto is led to the switch
contact, and wire No. 4 by which the high tension current from either
magneto or coil goes to the distributor. Wire No. 1 is low tension,
and conducts the battery current from the primary winding of the coil
to the battery interrupter. Low tension wire No. 2 is the grounding
wire by which the primary circuit of the magneto is grounded when the
switch is thrown to the off or to the battery position. Wire No. 5 leads
from the negative terminal of the battery to the coil, and the positive
terminal of the battery is grounded by wire No. 7; a second ground wire
No. 6 is connected to the coil terminal.
122. Bosch Two -independent System. — The Bosch two-independent
or double system consists of two complete and independent systems of
ignition. One consists of a Bosch high tension magneto system and the
other of a Bosch high tension distributor battery system.
The battery system is utilized for starting purposes and for emergency
ignition in case of accident to the magneto system, which is used for
ordinary service. The battery system consists of a combined coil and
switch and a timer-distributor, which are completely independent of the
magneto. The two systems are brought together at the switch, and the
connections are such that the engine may be operated on the magneto
with one set of plugs, or on the battery with the other set of plugs,
or on the magneto and battery together, in which case both sets of
174
THE GASOLINE AUTOMOBILE
plugs are used. Either the battery or magneto may be used for ignition
with the other system entirely dismantled or removed from the engine.
The wiring diagram for this system is shown in Fig. 204.
123. The Ford Magneto and Ignition System. — The magneto which
generates the current for the ignition system in the Ford car is of the low
tension alternating current type and differs from the conventional type
in that the stationary and revolving elements are interchanged.
The Ford magneto, as shown in Fig. 205, has but two parts, a sta-
tionary armature, consisting of a number of coils, which are attached
to a stationary support in the flywheel housing, and a set of permanent
field magnets of the horseshoe type, which are secured to the flywheel,
the whole being a part of the motor. The magnets revolve with the
flywheel at a distance of ^2 m- from the coils, in which the current is
FIG. 204. — Wiring diagram for Bosch two-independent system.
induced by the magnetic field. The current flows to the four spark coils,
passing through whichever one is at the instant connected to the ground
by the commutator. The coils are the ordinary double winding vibra-
tor coils. ^ The induced current from each coil goes to its spark plug to
perform its function of igniting the charge. The magneto and its
component parts are fully illustrated in Fig. 206.
The diagram of Fig. 207 shows the plan of wiring of the Ford Model
T motor, which, it will be noted, is very simple. The current generated
by the magneto flows through the primary winding of the coil whose
circuit is closed by the commutator, to the commutator, and back through
the frame of the motor to the magneto. This completes the primary
MAGNETOS AND MAGNETO IGNITION
175
circuit or path of the magneto current. The high tension induced in
the secondary winding of the coils is led to the spark plugs in the cylinders
as their respective primary circuits are completed by the commutator.
Magneto Coil Spoof
Copper Wire
End of Ribbon 1
Grounded Here J
To Coil
Magneto Coil Support
FIG. 205.— The Ford magneto.
124. Magneto Speeds. — Nearly all of the modern magnetos are con-
structed, as was pointed out in Art. 113, page 157, to give one spark for
each one-half revolution of the armature or inductor. This means that
FIG. 206. — Diagram showing the course of circuit through the Ford ignition circuit.
for each revolution, two sparks are obtained from the magneto. For a
four-cylinder four-stroke engine, there are two explosions per revolution
of the crank shaft. We see, therefore, that the magneto and engine
176
THE GASOLINE AUTOMOBILE
crank shaft must run at the same speed. For a six-cylinder four-stroke
engine, there are three explosions per revolution of the crank shaft, re-
quiring one and one-half revolutions of the magneto. The magneto
must, therefore, run one and one-half times the crank shaft speed. Some
magnetos are built to give four sparks per revolution. These must, of
course, be set to run at one-half the speeds given above.
125. Timing the Magneto. — Necessarily, the rules for setting and
timing magnetos must be very general. If the magneto has been removed
or is out of adjustment, the engine should be cranked until the No. 1
piston (the one next the radiator) is on dead center at the end of the
compression stroke. This position can usually be found by markings on
the flywheel. On some engines the manufacturers recommend that the
engine be cranked just a few degrees past the dead center. The position
will then be the firing position for the No. 1 cylinder.
Magneto
Contact Terminal
Commutator Wires
and Loom.
FIG. 207. — Wiring of the Ford ignition system.
The distributor housing should then be taken off and access gained
to the distributor mechanism. It should also be determined just which
cylinder corresponds to each of the distributor points. The armature
should then be rotated until the distributor segment comes in contact
with the distributor point for No. 1 cylinder. Adjust the armature so
that the contact points just break when the interrupter housing is in full
retard and attach it to the driving shaft. The spark control rod should
now be connected and adjusted so that the contact points just open, when
the spark lever on the steering wheel is in full retard. This permits the
maximum spark advance.
MAGNETOS AND MAGNETO IGNITION 177
126. Battery vs. Magneto Ignition. — It is a somewhat common idea
that an engine will run faster on a magneto spark than on a battery spark.
This contention has been frequently advanced in support of magneto
ignition. Extensive experiments on engines equipped with a double
system, one a magneto and the other a battery system, prove that with the
same spark setting, there is practically no variation in engine speed,
provided both systems are in perfect order and adjustment. In in-
dividual cases where the contrary has been found it was probably due to
some weakness or defect in the system which was replaced and should
not be taken as condemning that type of ignition in general.
127. General Suggestions on Magnetos. — The magneto should never
be tested unless the whole system is completely assembled with all parts
and wires in place and attached. Water should be kept away from all
parts of the ignition system. Magnetos were not intended to be run in
water.
Care should be taken when oiling parts of the magneto. A small
amount of oil properly placed is essential, but a great lot on everything
is a constant source of trouble.
Don't take the magneto apart or try to improve its construction.
Repairing a magneto is an expert's work. Unless you are one, don't
attempt it.
128. Common Magneto Ignition Definitions. — Low Tension Magneto.
— A magneto which generates a low voltage current, requiring a trans-
former coil to raise the voltage for ignition purposes. Only one wind-
ing is found on the armature.
High Tension Magneto. — One which generates current of high enough
voltage for ignition purposes. The armature contains two windings,
a primary and a secondary winding. No outside coil is necessary.
Armature Type Magneto. — One in which the current is generated by
a coil of wire wound around a core revolving between the poles of a
permanent magnet.
Inductor Type Magneto. — A type of magneto in which the coil is
stationary and the lines of force through the coil are changed in direction
by means of a rotating inductor.
Dual System of Ignition. — A system of ignition with two sources of
current, magneto and battery, either of which may be used. There is
practically no duplication of equipment, as the magneto timer, distributor
and plugs are used for both sources of current.
Double System of Ignition. — Two complete systems of ignition with
nothing in common excepting the switch on the dashboard. There
is a duplication of practically the entire equipment, plugs, timer, and
distributor.
CHAPTER VIII
STARTING AND LIGHTING SYSTEMS
129. Starting on the Spark. — If an engine is stopped with an explosive
mixture in the cylinder, it may sometimes be started from rest by merely
causing a spark in the cylinder. In a four-stroke engine having four or
more cylinders there will always be one cylinder on the expansion stroke
and one on the compression stroke. On a four-cylinder automobile
we can sometimes swing the spark lever so as to cause a spark in one of
these cylinders, and, if the compression has not been lost entirely, or the
gasoline vapor has not been condensed, the engine will start. Sometimes
an engine can be started in this manner after standing for several hours.
To make an engine more sure of starting on the spark, the throttle
should be opened wide before the engine is stopped. This will insure a
good charge in each cylinder. When a four-cylinder motor comes to
rest after the spark is shut off, one piston will be on its exhaust stroke and
another will be on its suction stroke, both of these cylinders, therefore,
being open to the air. A third piston will be on its compression stroke
with all valves shut and the fourth will be going down on the expansion
stroke with its charge still fresh because the current has been turned off.
The motor will come to rest with these two pistons on the same level,
each about halfway in the stroke. To start the motor, turn the switch
to the battery side and press the ignition starter button. Pressing the
ignition starter button short-circuits or cuts out the timer or circuit
breaker and causes current to flow through the primary winding of the
coil. Releasing the push button breaks the primary circuit and causes a
high tension current in the secondary circuit, which will be conducted
to a spark plug provided the distributor arm is opposite one of the
distributor segments.
If the engine comes to rest with the piston which is on the working
stroke on the same level with the piston which is on the compression
stroke, the distributor arm will be nearer to the segment leading to the
cylinder whose piston is on the working stroke. If the spark occurs in
this cylinder the engine will be run in the desired direction and if the
explosion is sufficient to carry the next piston over the top of the com-
pression stroke, the regular cycles will be continued; but if, when the
engine stops, the pistons have gone beyond the position where they are
on the same level, the spark is apt to occur in the cylinder which is on
179
18o THE GASOLINE AUTOMOBILE
the compression stroke. This explosion will drive the engine backward.
l^>ar the end of this backward stroke the inlet valve will open and the
burnt gases will be discharged through the carburetor.
If the engine is stopped so that the timer points or circuit breaker
points are in contact, it is impossible to start by pressing the ignition
starter button, but starting may be accomplished by retarding the spark
control lever and opening and closing the ignition switch, several times if
necessary.
The same method of starting will apply to two- or three-cylinder,
two-stroke engines. If a two-stroke engine is started by advancing the
spark, the motor will continue to run, but in the opposite direction from
that desired. A common way of starting a single-cylinder two-stroke
engine is to retard the spark and then turn the engine backward by hand
until the spark occurs. The engine will then be propelled in the desired
direction.
The failure of engines to start on the spark after standing for some
time is largely due to the gasoline vapor being heavier than air. After
an engine has stood for some time the heavy vapor will settle, and, if
the engine is cold, the gasoline may condense on the piston and cylinder
walls.
130. Mechanical Starters. — Self starters may be divided into four
general types: mechanical starters, air starters, acetylene starters, and
electric starters.
Mechanical starters include the various types of hand cranking
devices and springs. The disadvantage of the hand cranking starter is
that it requires a certain amount of human power. The only advantage
is that the driver does not have to leave his seat to crank the engine.
The spring starter is capable of giving the engine a few revolutions only,
and if the engine does not start then, it becomes necessary for the driver
to wind up the spring, which is a rather tiresome operation. If the
motor starts, there is an automatic device by which the spring is wound
up by the engine.
131. Air Starters. — In the air starters, the air is pumped into a storage
tank at about 150 Ib. pressure. The engine is started by admitting
air into the combustion chamber. The pipe leading from the tank goes
to a distributor which is driven by the motor. In this way the air gets
only to the cylinder which is on the working stroke and has all the valves
closed. This system has the disadvantage that the air is liable to cool
the cylinder and prevent proper starting of the regular cycle on account
of the gas condensing on the cool walls.
132. Acetylene Starters. — Some manufacturers have equipped their
machines with a device for starting with acetylene gas. This gas is
very explosive and will ignite readily under almost any conditions.
STARTING AND LIGHTING SYSTEMS 181
These engines are equipped with valves and tubes from the acetylene
lighting system so that the driver can inject a small quantity of acetylene
gas into the cylinders. The engine will then be practically sure of start-
ing on the spark. This system has been largely superseded by the
electric starter.
133. Electric Starters. — A still further development in this line is the
electric starter. Electric starters may be divided into three types:
first, the single-unit system; second, the two-unit system; and third, the
three-unit system. In the first system the motor-generator unit furnishes
the current to charge the storage battery and operate the lights, and
also acts as a motor in cranking the engine. The two-unit system
has a generator for charging the battery and furnishing the current for
lighting and ignition, but it has a separate unit (a direct current motor)
for cranking the engine. The three-unit system has a generator used
solely for charging the battery and operating the lights, a motor for
cranking the engine and a magneto for furnishing current for ignition.
In all electric self-starters it is necessary to have a storage battery to
store up the current so that there is a ready source of sufficient current to
drive the motor for starting. The units of the self-starting system are:
the generator to furnish electricity; the storage battery which acts as a
reservoir to hold the supply of current ; and an electric motor to crank the
engine. The electric starter may be directly connected to the gas engine,
or it may be driven by a set of gears, or by a silent chain.
In order that the electric motor will not be overspeeded when the
engine picks up, it is necessary to have an overrunning clutch. This
device operates only when the engine runs faster than the motor. The
reduction in gears between the electric motor and the engine is about 25
to 1, which means that the electric motor must run twenty-five times as fast
as the engine. If it were not for the over-running clutch, the electric motor
would be driven at excessively high speed, when the engine picks up
to, say, two or three hundred revolutions per minute. The over-running
clutch is automatic. It permits the electric motor to drive the engine, but
breaks the driving connection as soon as the engine speeds up to a
higher rate than the motor is running at. In the one-unit and two-unit
systems, the current for ignition is taken from the storage battery. In
all cases the current for the lights comes from the battery when the
engine is running at low speeds.
There is also another type of self starter which takes the place of
the engine flywheel. This unit is a motor-generator outfit and has no
reduction gear whatever.
134. Storage Batteries. — A commercial storage cell, as shown in Fig.
208, is made up of the following parts: a jar or container usually made
of rubber, positive and negative plates, separators between the plates, and
182
THE GASOLINE AUTOMOBILE
the electrolyte. The electrolyte is a solution of sulphuric acid and
water. After the plates are prepared, they are placed in the container
and the electrolyte added. The current is then passed through the
plates and solution. In this manner the battery is charged. When
the battery is fully charged, the electrolyte or solution in the cells should
have a specific gravity of 1.27 to 1.29. The specific gravity will become
lower as the battery discharges and, when completely discharged, should
not be lower than 1.15 to 1.17, or about twelve points less than when fully
charged. Water must be added occasionally to replace the loss by
evaporation. If one cell regularly requires more water than the others,
it is an indication of a leaky jar. A leaky jar should be immediately
replaced by a new one. The specific gravity of the electrolyte is the
Expansion
Chamber
Sealing
Compound
Mud Spaces
• FIG. 208.— Section of storage cell.
most reliable indication of the state of charge of the battery. It should
never go below 1.15, for below that the battery will not have sufficient
power to turn over the engine and it will not burn the lights so as to
give the full candle power. The electrolyte must always cover the plates.
The loss by evaporation should be replaced by adding pure fresh water.
The water for filling the batteries must be either distilled water, melted
artificial ice, or fresh rain water. Never add acid. The batteries should
be inspected once every 2 weeks and, if the electrolyte is below the
bottom of the filling tubes, water enough should be added to bring the
level up to the proper point. Ordinarily it will require only a few spoon-
fuls. The filling plugs must be replaced and screwed up tight after
filling. Never keep the supply of water in a metal container, a bucket or
STARTING AND LIGHTING SYSTEMS 183
can. It is best to get a bottle or jug of distilled water from your druggist
or from the ice plant. The main point is to keep metal particles out of
the battery. Spring water, well water, or hydrant water from iron pipes
will contain iron and other materials in solution which will cause trouble
by short circuiting the plates.
If the electrolyte has been spilled from a cell, replace the loss with
new electrolyte and follow with an overcharge, either by running the
engine for several hours, or by charging from an outside source. In
replacing electrolyte, have the specific gravity the same as in one of the
adjacent cells. This can be determined by use of the hydrometer.
When new electrolyte is required, either to replace loss from spilling, or
when removing the sediment, or to replace a broken jar, it can be made
by mixing chemically pure sulphuric acid, having a specific gravity of
1.84, and distilled water in the proportions of 1 part of acid to 3 parts of
water, by volume. The acid should always be poured into the water, and
not the water into the acid. A glass, or other acid-proof vessel, thor-
oughly cleaned, should be used for mixing the electrolyte. When
replacing the cell, be sure that the positive and negative connections
have the same positions as before. Then apply vaseline or grease to the
studs and nuts before making the connections.
After standing for some time, sediment will accumulate in the bottom
of the jar. This should always be removed before it reaches the bottom
of the plates. It can be determined by inspection, and will be indicated
by lack of capacity, excessive evaporation and overheating when
charging. If the battery needs repairing, it is best to communicate with
the manufacturers who will advise you what to do. The battery is the
heart or center of the system. The electricity generated by the dynamo
is stored in the battery, and is used by the starting motor to crank the
engine, and for the lights at low speed and when the engine is at rest.
When the current flows from the dynamo through the battery elements,
it is termed charging, and when the battery is supplying current for crank-
ing the engine or to the lights, it is termed discharging.
Immediately upon receipt of a battery or new automobile, the battery
should be inspected. Remove the vent plugs. See that the battery
plates are well covered with solution, and if it is not up to the inside cover
(see Fig. 208) add distilled water. Filling one cell does not fill all the
cells. The battery, if neglected, will cause the entire system to fail. The
starting motor may operate when the battery is weak, but the battery
life is thereby shortened. If, however, the battery is kept fully charged,
and properly supplied with pure water, it will give uninterrupted service.
The majority of car owners are careless about giving the battery the
attention it should have. Remember that if the plates are exposed (not
184
THE GASOLINE AUTOMOBILE
covered by battery solution) they become sulphated and hard, and the
battery capacity is greatly reduced.
Specific gravity tests are made with the hydrometer. When the
battery does not give the desired results, specific gravity tests of each cell
will indicate the faulty cell or cells. Figure 209 shows the
ordinary type of hydrometer syringe used in determining
the specific gravities of solutions.
The action of this hydrometer is similar to that shown
in Fig. 95, but it is contained in a syringe by which a
sample of electrolyte may be drawn from the cell. To use
the hydrometer expel the air from bulb by pressing it.
Then insert the nozzle into the battery opening and allow
the depressed bulb to draw sufficient electrolyte into the
syringe to float the hydrometer. The specific gravity or
density of the electrolyte is then indicated by the number
on the hydrometer stem at the surface of the electrolyte.
Always return the battery solution to the cell from which
it was taken.
Take the hydrometer readings just previous to adding
water. If the hydrometer readings show that one cell is
discharged, or nearly so, while the other cells are charged,
it indicates that the cell is defective. This may be due to:
1. Short circuits in that particular cell, thus discharg-
. , ing it-
I 2. Sulphating of the plates, caused by infrequent filling
with water or by allowing to stand discharged.
3. Leak in the cell, thereby requiring more water than
other cells, which reduces the gravity.
Freezing of the electrolyte is avoided by keeping the
battery fully charged. As the specific gravity of the elec-
o* 209 trolyte decreases (result of discharging) , freezing will occur
—Hydrome- at temperatures as follows:
ter syringe.
FREEZING POINTS OP ELECTROLYTE
Specific gravity
1.285-1.300
1.260
1.210
1.160
1 . 120 or lower.
While it is possible to freeze a fully charged battery, it can be done only by
very low artificial temperatures.
If battery is allowed to remain discharged or if plates are not well
.covered, the elements become sulphated, and the capacity is thereby
Condition of charge
Fully charged.
34 discharged.
3^3 discharged.
% discharged.
Discharged.
Freezing point
Can not freeze.
50° below zero.
20° below zero.
0° zero.
20°-30° above zero.
STARTING AND LIGHTING SYSTEMS
185
Line (UP Volts direct Current)
3-15 Ann
Fuses
Lamps
reduced. Sulphate can sometimes be removed by a prolonged low
charging rate, but more frequently the battery is beyond redemption.
The plates should always be well covered and needless discharge
prevented.
If the starting motor is used unnecessarily for cranking the engine or
for propelling the car, rapid discharge takes place. Avoid this whenever
possible, as under this condition the
dynamo must be operated a long
time to replace in the battery the
amount of current taken by the start-
ing motor.
If the battery is neglected the
center and upper portions of plates
become sulphated. This condition is
not due to any fault of battery ma-
terial or construction nor to the start-
ing-lighting units, but is directly at-
tributable to inattention and neglect
on the part of the car owner who has
failed to add sufficient distilled water
to the solution in each cell, in order to
keep the plates properly submerged.
Be sure to add distilled water to the
battery every week or two.
135. Battery Charging.— Figure
210 shows how lamps are connected
in a direct current circuit for battery
charging. Connect a wire A from
one side of lighting source to one side
of these lamps, and to other side
connect another wire B. Then con-
nect wire C to the other side of light-
ing source. When the other end of
this third wire C is connected to the
end of wire B, the lamps should light.
Now determine which is the. positive
(+) and which is the negative ( — ) wire. Disconnect these two wires C
and B which caused lamps to light, and dip the ends in a bowl of water
containing a few tablespoonfuls of salt or one tablespoonful of battery
solution. Hold the immersed ends about 34 in- apart. The wire from
which the small bubbles rise is the negative ( — ) wire. This wire should
be connected to the negative battery post, marked Neg. or ( — ). The
other wire, which is positive (+) should be connected to the positive
FIG. 210. — Direct current charging
method.
186
THE GASOLINE AUTOMOBILE
battery post marked Pos. or (+), but not until the proper amount of re-
sistance has been determined.
If the direct current is at 110 volts any of the following sets of lamps
can be used as a resistance to permit a current of 4 amp. to flow into the
battery to charge it:
8-110 volt, 16 c.p. (50 watt) carbon lamps.
4-110 volt, 32 c.p. (100 watt) carbon lamps.
16-110 volt, 25 watt mazda or tungsten lamps.
7-110 volt, 60 watt mazda or tungsten lamps.
FIG. 211.— The Wagner rectifier charg
ttery.
The charging operation should continue for 24 to 30 hours, or for two
periods of 15 hours each.
If the voltage or pressure is 220 volts, use sixteen 220-volt lamps of 16
c.p. each, or eight lamps of 32 c.p. each; and charge for 24 to 30 hours.
If only alternating current is available the batteries can be charged by
STARTING AND LIGHTING SYSTEMS 187
a rectifier (see Fig. 211) which can be procured through an electrical sup-
ply house. A rectifier is an electrical device for changing alternating to
direct current. In ordering, state the voltage and frequency of the line
from which the charging current is to be taken. The ordinary lighting
circuit has a voltage of 110 and a frequency of 60, but it is best to get
this information from the electric light company. In addition to this,
the voltage and capacity of the battery must be given. To charge the
battery through a rectifier, connect the rectifier in the line, as shown in
Fig. 211, following the directions accompanying the instrument.
136. Wiring Systems. — Electric starting systems may be of the single
wire or the two wire system. In the two wire system, each unit, such as
lamps, motor, and coil, has two wires running to the battery. In the
single wire system, one side of the
battery is grounded, that is, one wire pBBHHBHB
is bolted to the frame of the car, and
each unit has only a one wire connec-
tion. In this method it is necessary
to have some sort of cut-out, so that
if the single wire should become
grounded to any metallic part, it
would not injure the battery. Any
ground on the single wire system
would, of course, short-circuit the bat-
tery. The cut-out will allow only a
certain amount of current to flow and i
anything in excess of this will cause FlG. 212.— Ward-Leonard controller,
sufficient magnetism in the core of the
cut-out to break the circuit. This action can be detected by a clicking
noise, similar to the working of a telegraph instrument.
There are a large number of starting and lighting systems on the
market, the details of which we will now take up. The most important
technical features to study are the different methods of controlling the
output of the dynamo.
137. The Ward-Leonard System. — The Ward-Leonard constant cur-
rent type of controller is shown in Fig. 212 and operates as follows:
The proper charging of the battery is automatically regulated by the
controller. When the car speed becomes approximately 7 miles per hour,
the dynamo armature will give a voltage sufficient to charge the batteries.
The circuit between the dynamo and the batteries is normally open, but
when the voltage of the dynamo becomes proper for charging, the coil
A on the magnet core B magnetizes the core sufficiently to attract the arm
C. This arm moves toward the core B, and thus two spark-proof
points D and D' are brought together, establishing the circuit be-
188
THE GASOLINE AUTOMOBILE
tween the battery and the dynamo, and the dynamo begins to charge
the batteries.
Unless some method of controlling it is adopted, the dynamo voltage
increases with the speed. The dynamo should charge at about 7 miles
per hour, but when the car runs at a much higher .speed, as 15 to 60
miles per hour, it is desirable that the dynamo voltage shall not increase.
If allowed to increase, such an excessive dynamo voltage would
tend to cause sparking at the brushes, excess current and consequent
trouble at the commutator, and excessive wear and heating of the bear-
FIG. 213. — Ward-Leonard wiring diagram.
ings. It would also cause an excessive amount of current to flow through
the battery. To prevent this, the strength of the dynamo field, and con-
sequently the output of the dynamo, is made dependent on the touching
of the two points E and E'. The coil F on the magnet core G carries
the armature current, and if this current becomes a certain amount
(usually in practice 10 amp.) the core becomes sufficiently magnetized to
attract the finger H. This separates the contacts E and E', and a re-
sistance M is inserted in the field circuit. This weakens the fields and
causes the amperes to decrease. When the current decreases to a pre-
determined amount (say 9 amp.), the coil F does not magnetize the core
Cr enough to overcome the pull of the spring J. The spring pulls together
STARTING AND LIGHTING SYSTEMS
189
the points E and E'; the full field strength is restored and the current
tends to increase. Under operating conditions the finger H automatically
and rapidly vibrates at such a rate as to keep the current constant.
As a result, the dynamo will never charge above a predetermined amount
(10 amp.) no matter how high the speed of the car, but will produce a
substantially constant current.
In case the engine speed becomes so low that the dynamo volts are
less than those of the battery, the magnetism caused by the coil A,
Fig. 212, is weakened so that the spring K pulls the contacts D and Df
apart. Thus, the circuit between the dynamo and battery is opened
FIG. 214. — Installation of Ward-Leonard system.
when the dynamo speed is too low for proper charging. An auxiliary
series coil L on core B acts to insure the perfect demagnetization of the
core on reversal of current.
The technical internal wiring diagram, in Fig. 213, shows the con-
nections of the dynamo, the battery and the controller. Figure 214
shows a typical installation and wiring layout for the complete two-unit
starting and lighting system. The connections of the motor are very
simple. There are two wires from the battery to the motor, with a
switch operated by the foot pedal. This pedal also shifts the starting
gears into mesh with the teeth on the flywheel. When the engine starts,
the foot pedal is released, the gears are disengaged, the switch opened
190
THE GASOLINE AUTOMOBILE
and the motor becomes inoperative until it is wanted to start the engine
again.
138. The Delco System. — A single-unit motor-generator is used in this
system. This unit also carries, mounted on it, the ignition system. A
general view of a Delco system is shown in Fig. 215. The motor-generator
has separate sets of brushes, commutator, and windings — one used when
serving as a motor and one when acting as a generator. It also has two
driving connections. When acting as a generator, it is usually driven
from the pump shaft by a clutch connection as shown at the right in Fig.
216, which shows the motor-generator as used on the 1915 Buick cars.
When the starting pedal is operated, this clutch is disconnected, the gear
FIG. 215. — Delco starting and lighting system.
connection is made from the motor pinion to the flywheel, the brushes are
removed from the generator commutator and the motor brushes put into
contact with the motor commutator. When the pedal is released, the
connections are made to operate as a generator.
Voltage Regulator. — The Delco system of current regulation uses a
resistance coil immersed in a tube of mercury, as shown in Fig. 217.
This instrument serves to control the amount of current flowing from the
generator to the storage battery. By referring to Fig. 217 the construc-
tion and operation of this device will be made clear. A magnet coil A
surrounds the upper half of the mercury tube B. Within this mercury
tube is a plunger C, comprising an iron tube with a coil of resistance wire
STARTING AND LIGHTING SYSTEMS
191
wrapped around the lower portion on top of a special insulation. One
end of this resistance wire is connected to the lower end of the tube, the
other end being connected to a needle D carried in the center of the
plunger. The lower portion of the mercury tube is divided by an
insulating tube into two concentric wells, the plunger tube being partly
immersed in the outer well, and the needle in the inner well. The space
in the mercury tube above the body of mercury is filled with an especially
treated oil which serves to protect the' mercury from oxidization, to
lubricate the plunger, and to form a dash pot for the plunger. Inasmuch
as the voltage of the storage battery varies with its condition of charge, the
intensity of the magnetic pull exerted by the magnet coil A upon the
STARTING
/PEDAL
\W fnll
FIG. 216. — Delco motor-generator.
nSTRBUTOR SHATT
SPRAL GEAR
plunger C varies, and causes the plunger to move in and out of the mercury
as the voltage changes. When the battery is in a discharged condition,
the plunger C assumes a low position in the mercury tube. When the
plunger is at a low position, the coil of resistance wire carried upon its
lower portion is immersed in the mercury, and as the plunger rises the coil
is withdrawn. Now the current to the shunt field of the generator must
follow a path leading to the outer well of mercury, through the resistance
coil wound on the plunger tube, to the needle carried at the center of the
plunger, into the center well of mercury and out of the regulator.
It will be seen that, as the plunger is withdrawn from the mercury,
more resistance is thrown into this circuit, due to the fact that the current
must pass through a greater length of resistance wire. This greater
resistance in the field of the generator causes the amount of current flow-
ing to the battery to be gradually reduced as the battery nears a state
of complete charge, until finally the plunger is almost completely with-
drawn from the mercury, throwing the entire length of resistance coil into
the shunt field circuit, thus causing a condition of practical electric
192
THE GASOLINE AUTOMOBILE
balance between the battery and generator, and obviating any possi-
bility of overcharging the battery.
Automatic Cut-out Relay. — The automatic cut-out, Fig. 218, is located
between the voltage regulator and ignition relay, in the apparatus box.
This instrument closes the circuit between the generator and the storage
battery when the generator voltage is high enough to charge the storage
battery. It also opens the circuit as the generator slows down and its
voltage becomes less than that of the storage battery, thus preventing the
battery from discharging back through the generator. The cut-out
FIG. 217. — Delco voltage regulator. FIG. 218. — Delco cut-out relay.
relay is an electro-magnet with a compound winding. The voltage coil,
or fine wire winding, is connected directly across the terminals of the
generator. The current coil, or coarse wire winding, is in series with the
circuit between the generator and the storage battery, and the circuit is
opened and closed at the contacts A.
When the engine is started, the generator voltage builds up and when
it reaches about 6 volts the current passing through the voltage winding
produces enough magnetism to overcome the tension of the spring B,
attracting the magnet armature C to core D, which closes the contacts A.
These contacts close the circuit between the generator and storage battery.
STARTING AND LIGHTING SYSTEMS
193
The current flowing through the coarse wire winding increases the pull on
the armature and gives a good contact of low resistance at the points of
contact.
• When the generator slows down and its voltage drops below that of
the storage battery, the battery sends a reverse current through the coarse
wire winding, which kills the pull on the magnet armature C. The spring
B then opens the circuit between the generator and battery, and will hold
it open until the generator is again started up.
139. Gray and Davis Starting and Lighting System.— The Gray and
Davis starting and lighting system consists of a 6^ volt shunt wound
generator for charging the battery and furnishing current for the lights,
and a series wound motor for cranking the engine.
COMMUTATOR
FIELD COIL
f
ARMATURE
FIG. 219. — Gray and Davis generator.
The generator or dynamo is shown in Fig. 219. This generator has
two shunt field windings, so arranged that the field strength or magnetism
automatically increases as additional load comes on. The technical
wiring diagram for the whole starting and lighting system is shown in
Fig. 220.
Regulator Cut-out. — The regulator cut-out, shown in Fig. 221, per-
forms two duties: first, to regulate the dynamo for uniform output; sec-
ond, to connect the dynamo into the system only when sufficient current is
generated to charge the battery and to disconnect the dynamo from the
battery when the dynamo slows down so that the current is insufficient
to charge the battery, and thus prevent the battery from discharging
through the dynamo.
When the dynamo is at rest, the cut-out points are open and the
194
THE GASOLINE AUTOMOBILE
FIG. 220. — Technical wiring diagram with grounded switch — Gray and Davis
starting and lighting system.
STARTING AND LIGHTING SYSTEMS
195
regulator points remain closed. As the dynamo first speeds up, the regu-
lator points remain closed. Thus, the field resistance is cut out, permit-
ting the dynamo to build up under full field strength. When the proper
voltage is reached, the cut-out points close, permitting current to flow
through the series winding to the system.
As the dynamo speed increases beyond that necessary for full output,
the pull of the shunt winding attracts the regulator armatures. This re-
duces the pressure at the regulator points and inserts a resistance into
the field circuit, which prevents further increase of output. The vary-
ing of the pressure at the points, which allows the resistance to be put
into the circuit, is intermittent. The frequency is in proportion to the
speed variation.
SHIFTER PORK JPRING-
smrTER roRK
STOP COLLAR
SWITCH ROD -
FIG. 221. — Gray and Davis regulator
cut-out mounted on dynamo.
FIG. 222. — Gray and Davis starting
motor and connections.
The dynamo terminals are marked B and L. B is negative ( — ).
It is the end of the regulator cut-out series winding, and connects to the
battery through the indicator. L is also negative ( — ). It is con-
nected to the series winding at a given distance from the end and con-
nects to the lamps through the lighting switch. The positive brush-
holder of the dynamo connects or " grounds" to the dynamo frame.
Therefore, the dynamo frame is positive (+). Connections between the
dynamo and the regulator are as follows:
The three terminals at the end of the regulator cut-out opposite the
terminals marked B and L connect to the dynamo windings, as shown in
the wiring diagram.
A connects to dynamo negative ( — ) brush.
FI connects to the one field coil.
F connects to the other field coil.
The starting motor and its connections are shown in Fig. 222. The
starting motor cranks the engine until it runs under its own power. It
21
196
THE GASOLINE AUTOMOBILE
is the link between battery and engine. It converts electrical into
mechanical energy. Electrically it is connected to the battery through
heavy cables and the starting switch. Mechanically it is connected to
the engine through a gear reduction having a sliding flywheel-engaging
pinion and an over-running clutch.
The sliding engaging pinion and the starting switch are operated
by the same operation of the starting pedal, so that electrical and me-
chanical connection and disconnections occur at the same time.
When the starting switch is closed, the electrical energy stored in the
battery is instantly transmitted to the motor, causing the armature to
rotate. This mechanical energy is transmitted through the gears and
over-running clutch to the engine, causing it to rotate.
When the starting pedal is pressed to the full limit of its travel, it
moves the switch rod in the direction of the arrow in Fig. 222. This
moves the sliding pinion forward and
closes the starting switch. If the
sliding pinion is in a meshing posi-
tion, it slides into mesh with the fly-
wheel gear; but if the pinion teeth,
instead of sliding between, should
strike the ends of the flywheel teeth,
the switch rod completes its travel,
which compresses the shifter fork
spring and closes the switch. When
the pinion begins to turn, the com-
pressed spring throws the sliding
pinion into full engagement with the
flywheel gear and permits the start-
ing motor to crank the engine.
When the engine picks up, the roll
clutch prevents the engine from driving the starting motor, as the gears
are in mesh until the starting pedal is released.
Over-running Clutch. — The purpose of the over-running clutch is to
permit the engine, when cranked by the starting motor, to pick up with-
out speeding up the starting motor, which is temporarily connected to the
engine while the starting pedal is pressed. This over-running clutch
is merely a roller ratchet connection between one of the gears and its
shaft. This is shown on Fig. 222 and is shown more in detail in Fig.
223. The gears 1 and 2 are shown in the reversed position in Fig. 223
from that which they occupy in Fig. 222.
When the starting motor pinion No. 1 of Fig. 223 is rotated in a
counter-clockwise direction, the intermediate gear No. 2 rotates clock-
wise; the rolls No. 3 are thus rolled into the wedge angles between the
FIG. 223. — Gray and Davis over-run-
ning clutch.
STARTING AND LIGHTING SYSTEMS
197
curved surface of the clutch center No. 4 and the inner surface of the
intermediate gear No. 2, with increased pressure until the friction is
sufficient to drive intermediate shaft No. 5, which is keyed to clutch
center 4.
Springs No. 21, back of the plungers No. 22, keep rolls No. 3 firmly
within wedge angles so that they grip as soon as the starting motor
turns. When the engine runs faster than when rotated by the starting
motor, the rolls are released from the wedge angles, and the clutch center
4 can run ahead without carrying the gear 2 with it.
140. Wagner Starting and Lighting System. — The two-unit Wagner
system consists of the charging generator, Fig. 224, the starting motor,
Fig. 225, and the generator relay, Fig. 226. The wiring may be either
the two wire or single wire system at the option of the manufacturer.
FIG. 224. — Wagner generator.
The method of connecting the generator to the engine may be by a
silent chain or by spur or spiral gears. The starter motor may be con-
nected to the engine shaft by chain and over-running clutch, or by pin-
ion meshing with the flywheel and operated by the Eclipse Bendix system,
similar to the Westinghouse clutch shown in Fig. 229. The starting
motor turns the engine over at about 100 r.p.m., which is fast enough to
start on most magnetos.
In Fig. 224, E is the commutator and F, G, H, and / are the brushes.
The brushes H and I collect the current from the commutator and fur-
nish this current for charging the battery through the relay. The brushes
F and G collect from the commutator the current used for exciting the
fields.
The function of the relay, Fig. 226, is to connect the battery to the
generator when the voltage of the generator is slightly above the voltage
198
THE GASOLINE AUTOMOBILE
of the battery. It also disconnects the generator from the battery when
the voltage of the generator falls below the voltage of the battery. This
relay consists of two magnet coils, L and M , wound on an iron core N.
This iron core attracts and repels an iron lever 0. At the end of this lever
0 are two main contact points P and Q at which the contact between the
generator and battery is made and broken. There are also supplied two
auxiliary contact points R and S which are for the purpose of minimizing
the sparking at the main contact points P and Q. The coil M, called the
shunt coil, is connected directly across the two brushes H and /, Fig. 224,
and therefore the full generator voltage is impressed across the ends of this
coil. The coil L, called the series coil, is connected in series with the
FIG. 225. — Wagner starting motor.
battery and generator and therefore this coil carries the charging current
when the battery is being charged.
The action of the relay is as follows: When the engine is started, the
generator is driven by the engine, and it, therefore, increases and de-
creases in speed with the engine. When the engine is speeded up, the
generator follows with corresponding increase in speed and the voltage
of the generator rises as the speed increases. As soon as the generator
voltage gets to a point above the voltage of the battery, which is ap-
proximately 6 volts, the coil M , Fig. 226, pulls the iron lever 0 toward the
magnet core, thereby closing the contact at the points P-Q and R-S.
As soon as this contact is made, the generator is connected to the battery,
and a charging current will flow from the generator to the battery through
the series coil L, which is in series with the generator and battery. The
generator continues to charge as long as these contact points P-Q and R-S
remain together, but when the engine speed is decreased, so that the
generator voltage falls below the battery voltage, the battery will dis-
STARTING AND LIGHTING SYSTEMS 199
charge through the generator and therefore through the coil L. This
discharge current, being in the opposite direction from the charging current
will neutralize the effect of coil M and allow the spring T to pull the lever
0 away from the magnet core, thereby opening the contact at the points
P-Q and R-S. As soon as these contacts open, the battery is " off charge."
The engine speed at which this relay closes corresponds to a car speed of 7
to 10 miles per hour.
Studebaker automobiles use the Wagner system and are equipped
with an instrument called a Battery Indicator or Tell-tale. This instru-
ment is installed on the dashboard of the car and is connected in the
battery circuit. The tell-tale gives indication of battery current, showing
M L
FIGURES
RS PQ N O
FIG. 226. — Wagner relay.
off when no current is being taken from, or being put into, the battery;
discharge when current is being taken out of the battery by lights, ignition,
or horn; and showing charge when the generator is charging the battery.
141. The Westinghouse Single-unit System. — The Westinghouse
electric starter-lighter equipment consists of a motor-generator. In the
motor-generator the functions of both starting and lighting are combined
in one machine. A 12-volt system is used. The motor-generator is
permanently geared or chain-connected to the engine. When the circuit
is closed by the starting switch, the motor windings take current from
the battery and drive the engine until firing takes place. The motor-
generator is then driven by the engine, and, as speed increases, it soon
200
THE GASOLINE AUTOMOBILE
generates battery voltage. At all higher speeds it charges the battery and
furnishes the current for the lights.
There is an emergency feature on the Hupmobile that prevents stalling
of the engine. At low speeds the motor-generator acts as a motor and
assists the engine, causing an immediate restart in case of stalling.
It should be remembered that at speeds of less than 9 miles per hour,
with engine on high gear the motor-generator acts as a motor, assists
in propelling the car, and therefore takes current from the battery; and
if such running is indulged in to any extent the battery will become
exhausted. Also, allowing the engine to idle at low speeds will discharge
the battery. A little care in avoiding low speeds and engine idling will
FIG. 227.— Westinghouse Ford outfit.
prevent this. Figure 227 shows the Westinghouse single-unit system for
Ford cars, while the wiring diagram is given in Fig. 228.
142. Westinghouse Two-unit System. — 'The starting motor for the
Westinghouse two-unit system is shown in detail in Fig. 229. It may
be equipped with either a non-automatic or an automatic pinion-shift,
flywheel drive.
Figure 230 shows the mechanical and electrical connections of motor
and switch for non-automatic pinion-shift, flywheel drive. At A is
shown the "off" position of the shift pinion and switch contactor.
Pressure on the starting lever moves the shift rod first to the position
shown in B, closing the motor circuit at P and P' through the resistance
R; this starts the motor at low speed. Further motion of the shift rod to
position C opens the electric circuit but the motor and pinion continue
STARTING AND LIGHTING SYSTEMS
201
to turn, owing to their momentum. When position C is reached, the
pinion is still turning slowly, so that it can not fail to mesh with the gear,
but as power is turned off the motor, there is no difficulty in sliding the
teeth into full engagement. As soon as the teeth do engage, further foot
pressure on the starting lever shifts the rod to position shown in D,
closing the electric circuit at Q after the pinion and gear have meshed a
sufficient distance to present a good bearing length on the teeth; this
Head Lights-
7-1
Tail Light
FIG. 228. — Wiring diagram for Westinghouse Ford outfit.
connects the motor directly to the storage battery so that full power is
impressed, and it turns the engine over until the starting lever is released
or the engine picks up on its own power. There is an over-running clutch
between the flywheel pinion and the motor, so that, if the pedal is not
promptly released when the engine picks up, the motor is not driven by the
engine.
202
THE GASOLINE A UTOMOBILE
L
ARMATURE COMMUTATOR . ':". ^ ... .
FIG. 229. — Westinghouse starting motor disassembled.
FIG. 230.— Connections of Westinghouse starting motor with non-automatic
pinion shift.
STARTING AND LIGHTING SYSTEMS
203
In the Eclipse-Bendix pinion-shift, as shown in Fig. 231, the starter
motor is fitted with a special threaded shaft which automatically shifts
the pinion into mesh with the flywheel when the starting switch is closed.
When the switch is closed, the full battery voltage is impressed on the
motor, and it starts immediately. The pinion, when the motor is at rest,
is within the screwshaft housing and entirely away from the flywheel
gear. The threaded shaft is connected to the reduction gear shaft by a
spring which thus forms a flexible coupling. As the load is not large
enough to compress the spring when the motor starts, the threaded shaft
is immediately revolved by the spring in released position. The pinion
moves out on its shaft by virtue of the revolving threads, until it reaches
the flywheel. If the teeth of the pinion and flywheel meet instead of
tortmg Motor
[lectn-Magnetic
Starting Switch r
'orting Motor
A, With hand or foot
operated starting switch.
B, With electro-magnetic starting switch
controlled by push button.
FIG. 231. — Connections
of Westinghouse starting
pinion shift.
motor with Eclipse-Bendix
meshing, the spring allows the pinion to revolve until it meshes with the
flywheel. When the pinion is fully meshed into the flywheel teeth, the
spring compresses, and the pinion is then revolved by the motor as
through a continuous shaft, turning the engine over. When the engine
fires and the peripheral speed of the flywheel continuously exceeds that
of the driving pinion, it forces the latter out of mesh, and it is returned to
its original position in the screwshaft housing.
The Westinghouse lighting and starting generator, as shown in detail
in Fig. 232, is operated by belt, chain, or gear drive from the engine and
furnishes current to the storage battery and lights. While the engine is
stopped or running at very low speed, the lights are supplied entirely by
the battery. A magnetic switch in the generator automatically con-
nects the generator to the lighting system and battery when the engine is
running at approximately 8 miles per hour car speed on. direct drive.
When running on the gears,the switch closes at a much lower car speed.
If no lights are then in use, the battery begins to be charged when this
switch makes the electrical connection. If the lights are burning, the
204
THE GASOLINE AUTOMOBILE
generator furnishes part of the current to them; as the speed increases, the
proportion of current supplied by the generator increases, until at high
speed the generator supplies all of the current to the lights and in addition
charges the battery. The amount of current the generator furnishes to
the battery depends upon the number of lamps burning and upon the
speed of the engine.
143. The U. S. L. Electric Starting and Lighting System.— This is a
unique system in which a single unit motor-generator is connected directly
to the engine shaft, taking the place of the flywheel.
The motor-generator consists of a stationary housing, a set of fields
complete with poles and coils, an aluminum case, and a dust ring, as
CO
•-• .
BRUSHE!
FIG. 232. — Westinghouse starting and lighting generator disassembled.
shown in detail in Fig. 233. The armature replaces the flywheel of the
engine, being attached to the crank shaft in its stead as shown in Fig. 234.
When the starting button is pressed down, the current from the battery-
starts the electric motor. This revolves the crank shaft of the engine.
With the switch of the ignition coil in battery position, the explosions will
commence. The starting button should be quickly released, thus auto-
matically changing the electric motor into an electric generator. As the
speed of the engine increases, the generator gradually commences charging
the battery, restoring the current discharged during the starting operation.
Regulator. — The regulator is located on the dash under the cowl and
instrument board. It performs four principal functions: 1, closes the
switch when the generator voltage is sufficient to charge the battery;
2, opens the switch when the generator voltage is insufficient and the
STARTING AND LIGHTING SYSTEMS 205
current reverses; 3, regulates the maximum charge to the battery; and 4
controls the generator voltage on open battery circuit.
An indicating arrow is visible through the window in the regulator
cover when the switch is closed and the storage battery is being charged.
It disappears when the contact is broken. The switch should close when a
car speed of 10 to 12 miles per hour is attained, and open when the speed
falls below about the same rate, or when the motor stops altogether.
The regulator consists of a magnet coil which pulls the switch lever
into contact when the proper car speed is attained. It also acts on a
carbon pile lever and controls the field current by increasing or decreasing
the resistance through the carbon discs at the top of the regulator.
CASE & FIELDS RATCHET SPRING
Fia. 233.— Details of U. S. L. system.
If the engine does not turn over when you first press on the button,
immediately let up the button and try again several times quickly. Do
not hold your foot on it long, as this will needlessly drain the current from
the battery.
If the motor fails to respond when the starter button is pressed
several times quickly, the battery is too low. In such cases, do not continue
to hold the starting button down ; release it, and crank the motor by hand,
running it at a charging rate of 10 to 15 amp. giving the generator an
opportunity to recharge the battery. If you repeatedly press the starting
button without running the engine, it will only be a question of time before
the battery will be exhausted.
144. Jesco Single -unit Electric Starter and Lighter. — The complete
system consists of a starter-generator, with controller and starting switch
206 THE GASOLINE AUTOMOBILE
mounted thereon, in connection with a 6 volt, 100 amp.-hour storage
battery, switch, and wiring for lights. The starter-generator is connected
either by coupling, by silent chain, or by gears to the crank shaft of the
engine, at a ratio of either one to one, or two to one.
The electric machine performs as a series motor at time of starting
and as a shunt generator for storing current in the battery and supplying
the lights. As a starter, a gear reduction is automatically engaged, and
CLUTCH BEARING GREASE CU
CRANK SHAFT
LOCKING NUT
CRANK SHAFT EXTENSION BOL
BALL THRUST WASHER
BALL THRUST
CLUTCH FLANGE NUT
CLUTCH SPRING THRUST WASHER
CLUTCH SPRING
CLUTCH CONE BUSHING
CLUTCH CONE
CLUTCH LEATHE
FIG. 234. — Section of U. S. L. motor-generator.
after the engine starts, this transmission locks by action of a multiple disc
clutch, and no gears are in operation. This works automatically and
requires little attention, outside of oiling. The electrical regulating mech-
anism is contained in the little box on top of the starter-generator.
The regulation is taken care of by a differential shunt field in connection
with an automatic regulator.
Charging begins at approximately 8 miles an hour car speed. At 15
miles an hour the maximum charging rate is reached and, by regulation,
remains constant through all speeds in excess of that amount. The
STARTING AND LIGHTING SYSTEMS 207
battery cut-out automatically disconnects the battery when the generator
is not charging, preventing a back flow from battery to machine.
The wiring is extremely simple, having only two leads from starter-
generator to battery, with the lighting of car and the indicating meters
arranged as desired. The Jesco system as used on a Continental six
engine is shown in Fig. 235.
145. Care of Starting and Lighting Apparatus. — A periodical in-
spection should be made of wiring, insulation and all connections. Wir-
ing and connections should be protected against grease, oil, and me-
chanical injury.
FIG. 235. — Jesco starting installation.
Use the same consideration for your auto lighting system that you
do for electric light in your house. Do not leave your car all night with
all lights burning and expect to find a well charged battery in the morning.
Be sure that all wires are perfectly insulated and not in contact
with any moving parts, as the constant rubbing will wear off the insula-
tion and the vibration will cause the connections to become loose.
All permanent connections should be well soldered, all stray strands
of wire removed and the joints properly taped in order to prevent loss
of current from short circuits. If wires must be run where there is
208 THE GASOLINE AUTOMOBILE
liable to be grease, oil, or water, they should be protected by conduit
or other oil or waterproof material. Either oil or water will cause the
insulation on the wire to be of very little value.
The generator should be inspected about every month and kept
clean. The commutator may become rough and blackened and should
'be cleaned by holding a piece of fine sandpaper against it while rotating.
Then carefully remove all metallic particles from the commutator bars
that might cause a short circuit between them. A short circuit may also
be caused by carbon dust from the brushes.
The brushes should always have a perfect bearing surface on the
commutator. The general cause of a poor bearing is that the carbon
brush sticks in the brush holder. It may be taken out and filed down so
that it will slide easily in the holder.
When putting in new brushes, make sure that they fit perfectly
on the commutator. It is also a good policy to use only the brushes sent
out by the manufacturer of the machine.
If there is a grounded wire in the machine, or if a commutator segment
becomes loose, the armature should be returned to the factory for
repairs.
The carbon brushes contain sufficient lubricant for the commutator
so that it is not necessary to use any oil or grease of any kind. If grease
or oil should accumulate on the brushes or commutator, it should be
wiped off with a dry cloth.
The starting motor is intended to perform one function only, viz.,
to spin the engine, and should only be used for such purpose. Any
attempt to propel the car by the starting motor or indulge in the needless
use of same will result in trouble. Such experiments are of no material
value and it is no test of the power of the starting motor, but simply
imposes an extravagant demand on the battery. If these practices are
indulged in they will result in a complete discharge, which is detrimental
to the life and service of the storage battery.
146. Starting Motor Troubles. — The closing of the starting switch
completes the circuit between the battery and the motor, and puts the
starter in operation. If the starter does not turn the engine over, release
the switch at once and ascertain if all connections are tight and secure,
and inspect the battery. If the starting motor turns the engine over
very slowly, it is evident that the battery is weak or the engine stiff.
If the starting motor is turning the engine over at a reasonable cranking
speed and the engine does not fire, remember that the starting motor is
performing its duty, so do not let the starting motor continue to crank
the engine longer than necessary, as a needless drain is placed on the
battery. If the engine does not fire, it is evident that the trouble is
confined to the carburetor or ignition.
STARTING AND LIGHTING SYSTEMS 209
147. Generator Troubles.— A simple test to determine if the generator
is properly operating is, first, to switch all the lights on with the engine
idle; second, to start the engine and run it reasonably fast. If the lights
brighten perceptibly after starting the engine, it proves that the generator
is properly delivering current. This test must necessarily be conducted
in the dark, either in the garage, or preferably, at night time. Generator
troubles will be manifested by dim lights when the engine is running at a
medium rate or by failure to keep the battery charged. The trouble
may be caused from, first, grounds or short circuits in the field windings;
second, increased resistance in circuit, caused by dirty commutator or
brushes, weak brush springs or poor material in the brushes (poor ma-
terial in brushes causes sparking and overheating) ; third, grounds in the
armature, caused by defective insulation or carbon deposits on the
commutator short-circuiting the copper bars; fourth, circuit breaker or
regulator not properly adjusted so that the battery is not cut in at proper
time. The contact points may become dirty or corroded or may be
burned by an excess of current, generally from a reverse current from
the battery.
148. Battery Troubles. — Battery troubles may be detected by failure
to turn the motor or by the lights burning dimly when the engine is
stopped. Battery troubles can be traced to improper charging; loss
of electrolyte; short circuits, either external or internal; overloading,
caused by using light bulbs of too large capacity; burning lights when not
necessary; and propelling car with starting motor. External short
circuits may be caused by broken insulation so that two bare wires come
together or come into contact with the frame of the car or other conducting
material, or may be caused by acid on top of battery forming circuit
between terminals. Internal short-circuiting is explained in Art. 134.
If the starting motor will not crank the engine, the trouble may be
looked for as follows:
1. Battery discharged.
2. Broken circuit caused by worn out or dirty brushes or weak
springs, or broken connections or short circuits in any part of the wir-
ing or switches. A dirty commutator will have the same effect as
dirty brushes.
If the starting motor cranks the engine very slowly, the trouble
may be caused by the battery being partly discharged or by an excess of
resistance in the circuit. The increased resistance may be caused by
loose connections in wiring, poor contacts in switch, dirty brushes or
commutator, brushes made from unsuitable material or not held firmly
on the commutator.
149. Winter Care of Batteries. — If the car is not to be used for some
time, as in the winter, the batteries should be inspected before the car is
210 THE GASOLINE AUTOMOBILE
used for the last time. Water should be added to the cells, if necessary,
so that it will thoroughly mix with the electrolyte when the car is driven.
When the car is laid up, the specific gravity of the electrolyte should
register from 1.27 to 1.29. In this condition there will be no danger of
freezing in any climate. The battery should be charged every two
months during the "out of season" period, either by running the engine,
or by charging from an outside source. If either of the above methods
is impossible, and there is no garage convenient that is equipped for
charging batteries, the battery may be allowed to stand without charging
during the winter, providing it is fully charged at the time the car is
laid up. Much better results, however, and longer life of the battery
will be obtained by giving the periodic charges. The wires of the
battery should be disconnected during the "out of season" period in
order to prevent any slight leaks that might occur in the wiring.
150. "Don'ts" on Starting Equipment. — Don't disconnect the battery
and start the engine up with any of the lamps in circuit. This is very
important as the battery acts as a voltage regulator and, if not con-
nected, the lamps or fuses in the circuit connected will be blown out
immediately, due to heavy rise in voltage from the generator.
Don't attempt to work around the lighting system without dis-
connecting the battery ground and winding it with tape. It is a very
easy matter to touch a screw-driver or a pair of pliers from a live wire
to the frame or to the pipes or engine, thereby causing short circuit and
blowing out a fuse. When the work is finished, replace the ground wire
before starting the engine.
Don't try to repair or readjust any of the instruments supplied.
Leave this to the manufacturers whose experience in this field will in-
sure handling the job in a better manner than you can.
Don't leave the starter button in the socket while the motor is running.
Don't stamp on the starter button, but press it down deliberately
and firmly.
Don't fail to go over the wiring occasionally and see that all binding
posts are tight and free from corrosion.
Don't fail to remember that the mechanism is an electrical starter
and not a motor for vehicle propulsion.
Don't expect the starter to spin the motor at a maximum cranking
speed if the battery voltage is run down. Endeavor to run the car with
fewer lights for a while and allow the voltage to pick up.
Don't abuse the electric starter. The mechanism is strong and
durable and guaranteed for the purpose intended, but is not guaranteed
against rough treatment or inexcusable abuse.
Don't fail to inspect all terminals occasionally and see that the
tape which protects these terminals from short-circuiting is in good
STARTING AND LIGHTING SYSTEMS 211
shape. In case this has become unwrapped, it is advisable to replace
immediately with fresh insulating tape of good quality.
Don't try to hook up additional electrical equipment without care-
fully going over the wiring diagram to find the proper place for such a
connection.
Don't fail to see that the ground wire from the battery has a good
contact between the terminal and frame.
Don't fail to carry extra fuses and lamp bulbs.
CHAPTER IX
AUTOMOBILE TROUBLES AND REMEDIES
151. Classification of Troubles.— The manufacturers of automobiles
are constantly striving to simplify the design and construction of all
parts in order to reduce the number of troubles which are a constant
source of worry to the automobile owner and driver. They have been
HIGH TENSION CABLE
Insulation worn off,
cable not attached
SPARK PLUG
Broken, fouled, loose, \
gap too wide "••^ A
VALVE: CAP--*
WATER SPACE
Filled with sediment
PRIMING COCK
I Loose
VALVE
Pitted, scored. ~~~~-
covered with carbon
MANIFOLD JOINT-^
Not tight
VALVE STEM —
Bent, stuck
VALVE SPRING
Too weak, broken,
out of place
CLEARANCE-
To much or too /it tie
THROTTLE. VALVE
Disconnected from
throttle valve rod
GASOLINE FLOAT^
Soaked or logged
FLOAT VALVE."'
Stem bent seat
leaks, valve stuck
on seat
GASOLINE NEi
VALVE:
Bent or stutk
CAM
Contour worn
^P/STON RINGS
Loose, broken,
misplac.ec/
^PISTON
Worn, too loose,
out of round ',
— WRIST PIN
Worn, loose
— CYLINDER WALLS
Scored, worn
..D/STRIBUTOR
Dirty
T/MER LEVER
- INTERRUPTER
OR TIMER
Contact points not
proper/y adjusted
TIMING GEARS '
Gears not meshed
properly
CRANK PIN
Worn, out of
round
CONNECTING ROD
BEARING
Loose, worn
'-CRANK SHAFT
Bearings worn
FIG. 236. — Chart showing location of common mechanical troubles of engines.
quite successful in reducing troubles to a minimum; as a matter of fact,
the possible troubles on the modern car are now few in number com-
pared to those of not a great many years ago. The troubles now com-
monly experienced are those inherent in every man-made machine which
is subject to the wear and tear of everyday use.
213
214 THE GASOLINE AUTOMOBILE
It is obviously impossible in many cases to give a direct statement of
a cure for all of the various symptoms which are likely at some time or
other to confront the motorist, as some symptoms may be due to any
one or more of several different causes. All that can be done is to offer
a few general suggestions which will assist him to diagnose his own
specific troubles and apply the proper remedy.
The automobile is a fine piece of machinery and the service from it
will depend upon the care and attention given to it. Many of the
troubles on the modern automobile are due to uncalled for adjustments
and investigations by the motorist. Although good care and attention
must be given in order to get efficient service, it is good policy to
leave well enough alone and not do any unnecessary tampering, nor
try to improve upon the operation or construction as planned by the
manufacturer.
The more common motor car troubles can be divided into the follow-
ing general headings:
I. II. III.
Power plant troubles Transmission troubles Chassis troubles
(a) Mechanical parts of engine. (a) Clutch. (a) Wheel hubs.
(6) Carburetting and gasoline (6) Change gears. (6) Steering gear.
system. (c) Differential. (c) Brakes.
(c) Ignition. (d) Rear axle. (d) Springs.
(d) Lubricating and cooling. (e) Tires.
(e) Starting and lighting.
152. Power Plant Troubles.— Any derangement in the power plant
will show itself by one of the following symptoms. Under each symp-
tom is given the common causes with a reference to the discussion "on the
subject.
(1) Engine Fails to Start.
(a) Poor compression. See Art. 153.
(6) Engine cylinder flooded. See Art. 154(e).
(c) Carburetor adjustment not right. See Art. 154.
(d) Water in gasoline. See Art. 154(j).
(e) Carburetor frozen. See Art. 154 (g).
(/) Out of gasoline. See Art. 154(t).
(g) Engine too cold. See Art. 154(/).
(h) Ignition switch off.
(i) Foul or broken plugs. See Art. 155(6).
0') Weak batteries or magneto. See Art. 155(e,/, and g).
(k) Vibrators not properly adjusted. See Art. 155(A).
(0 Wiring system out of order. See Art. 155(d, ;, and k.)
(2) Engine Misses at Low Speeds.
(a) Poor compression. See Art. 153.
(b) Mixture too lean or too rich. See Art. 154 (a and 6).
AUTOMOBILE TROUBLES AND REMEDIES 215
(c) Spark plug gap too wide. See Art. 155(6).
(d) Spark plug cable not connected or short-circuited. See Art. 155 (d).
(e) Dirty interrupter. See Art. 155 (jfc).
(/) Dirty or defective spark plug. See Art. 155(6).
(g) Vibrator not properly adjusted. See Art. 155(h).
(3) Engine Misses at High Speeds Only.
(a) Carburetor not set for this speed. See Art. 154 (a and 6).
(6) Bad spark plug. See Art. 155(6).
(c) Weak valve spring. See Art. 154(6).
(d) Timer contact imperfect. See Art. 155 (ft).
(e) Vibrator points dirty or burned. See Art. 155(h).
(4) Engine Misses at All Speeds.
(a) Carburetor not properly adjusted. See Art. 154(a and 6).
(6) Dirty or broken plug. See Art. 155(6).
(c) Spark plug gap not right. See Art. 155(6).
(d) Poor compression. See Art. 153.
(e) Loose or broken terminals. See Art. 155(d).
(/) Weak batteries or magneto. See Art. 155(e, /, and g).
(g) Defective wiring. See Art. 155(d).
(h) Coil not properly adjusted. See Art. 155(h).
(i) Gasoline feed stopped up. See Art. 154(6 and h).
0') Needle valve bent or stuck. See Art. 154(6 and h).
(fc) Water in gasoline. See Art. 1540')-
(0 Poor circulation. See Art. 156(6).
(m) Excessive lubrication. See Art. 156 (a).
(5) Engine Overheats.
(a) Lack of proper circulation. See Art. 156 (a).
(6) Lack of proper lubrication. See Art. 156 (a).
(c) Slipping fan belt or bent fan blades. See Art. 156(6).
(d) Too rich a mixture. See Art. 154 (a).
(e) A weak mixture. See Art. 154(6).
(/) Running with spark retarded. See Art. 155(0-
(g) Carbon deposit in cylinders. See Art. 153(/) and 155(m).
(6) Engine Stops.
(a) Gasoline tank empty. See Art. 154(i).
(6) Water in gasoline. See Art. 1540').
(c) Carburetor flooded. See Art. 154(d).
(d) Lack of pressure on gasoline tank. See Art. 154(i).
(e) Overheating due to poor circulation or lack of lubrication. See Art.
156(o and 6).
CO Short-circuiting of wires or terminals. See Art. 155(d and j).
(g) Disconnected or broken wires. See Art. 155(d).
(h) Wet batteries or magneto. See Art. 155(d and e}.
(7) Engine Knocks.
(a) Carbon deposits in cylinder and on piston heads. See Art. 153 (/) and
155 (m).
(6) Spark too far advanced. See Art. 155(0-
(c) Running motor slow when pulling heavy load on direct drive. See Art.
155(0-
(d) Faulty lubrication. See Art. 156 (a).
(e) Engine overheated. See Art. 155(ra).
CO Loose connecting rod bearings. See Art. 153(0).
216 THE GASOLINE AUTOMOBILE
(g) Loose piston. See Art. 153 (e).
(h) Loose crank shaft bearing. See Art. 153(0).
(8) Engine Will Not Stop.
(a) Short circuit in switch.
(6) Magneto ground may be disconnected.
(c) Overheating and carbon deposits. See Art. 155(m)
(9) Lack of Power.
(a) Poor compression. See Art. 153.
(6) Too weak or too rich a mixture. See Art. 154 (a and 6).
(c) Weak spark. See Art. 155(e, /, g, and h).
(d) Lack of lubrication. See Art. 156 (a).
(e) Lack of cooling water. See Art. 155(6).
(/) Lack of gasoline. See Art. 154 (ft and i).
(g) Dragging brakes. See Art. 159(c).
(A) Slipping clutch. See Art. 158(a).
(**) Flat tires.
(j) Choked muffler causing back pressure.
(10) Back-firing Through Carburetor.
(a) Improper needle valve adjustment. See Art. 154(6).
(6) Dirt in gasoline passage or nozzle. See Art. 154(6 and h).
(c) Inlet valves holding open. See Art. 154(6).
(d) Excessive temperature of the hot water jacket of the carburetor, especially
in hot weather. This can be remedied by shutting off the water from
the carburetor jacket and cutting off the hot air supply.
(e) Spark retarded too far. See Art. 154(6) and 155(m). '
(11) Firing in Muffler.
(a) Weak mixture, slow burning exhaust, igniting unburned charge from pre-
vious "miss." See Art. 154 (6).
(6) Valves out of time.
(c) Too rich a gasoline mixture. See Art. 154(o).
(d) Occasional missing of a cylinder.
(12) Starter Witt Not Operate.
See starter troubles, Chap. VIII.
153. Mechanical Troubles in Engine. — {a) Poor Compression. — Poor
compression is one of the common causes for lack of power. Unless the
compression pressure is high enough, the explosion will be lacking in force
and the engine will be weak. The engine can be turned by hand, with
the ignition off, throttle open, and the compression noted in each cylinder,
or a more accurate way is to remove the spark plug and screw in a small
pressure gauge, which should show from 60 to 80 Ib. at the end of the
compression stroke, depending on the make of engine. Loss of com-
pression is commonly due to leaky or improperly seated valves, or to leaky
joints. Leaky thread joints, valve caps, and cracks in cylinder are
common causes for loss of compression. These can be detected by a
hissing sound or, if the suspected leak is covered with gasoline or oil, the
leak will show itself by bubbling through the oil. If the trouble can not
be located in this manner attention should be given to the valves.
As a rule, the intake valve requires less attention than the exhaust
AUTOMOBILE TROUBLES AND REMEDIES
217
valve, because the former comes into contact with the cool fresh fuel
charges, whereas the latter is apt to 'become fouled and burnt by the hot
and dirty exhaust gases. A frequent cause of leaky valves is carbon
deposit on the valve seats. These deposits prevent the proper seating
of the valve. The remedy is to clean and grind them.
b. Grinding Valves. — There are several good grinding compounds on
the market. It is advisable to use a coarse grade in the first operation and
then to finish off with a finer one to give a polished surface. A very good
homemade mixture is obtained by making a thin paste of a couple of
tablespoonfuls of kerosene, a few drops of oil, and enough fine flour
emery to thicken to the consistency of paste.
The valve spring must be removed so that the valve may be lifted
and turned. A moderate coating of the paste is applied to the bevel
face of the valve. Next rotate valve
back and forth until the entire bear-
ing surface is polished bright and
smooth the full width of the face. The
valve should never be turned the
whole way round. Rotate it back and
forth a quarter turn at most under
light pressure, lifting it up frequently
and turning it halfway round before
seating it again. This method distri-
butes the friction evenly and elimi-
nates the possibility of the emery
scoring the bearings. If no valve
grinding tool is available, the use of a
carpenter's brace or bit stock is recommended, as a much smoother
movement is thus obtained than by using a screw-driver. This method,
recommended by the Overland Company, is shown in Fig. 237.
After grinding to a good clean seat entirely free from spots or pits,
wash the valve, valve seat, and guide thoroughly in gasoline. If the
stem is rough or gummy, smooth it up with emery cloth but clean it
afterward before replacing it in the guide. To test the effectiveness of
your work, mark the valve seat in several places with a lead pencil and
turn the valve around a few times. If the marks are entirely rubbed off,
the work may be considered well done.
(c) Valve Adjustments. — Poor adjustments of the valve operating
mechanism may cause poor compression, even if the valve seats have been
properly ground in. The valve spring may be broken or too weak to
close the valve on its seat in the proper time. Sticking of the valves when
open may also be the cause of low compression.
The clearance between the valve stem and push rod may be the cause
FIG. 237.— Valve grinding.
218 THE GASOLINE AUTOMOBILE
of considerable trouble. This clearance is usually about the thickness
of a thin visiting card, the exact amount being somewhat different for
different cars, but never over ^2 m-
If this clearance for the intake valve is too great, the lift is reduced,
thus preventing the proper charge from getting into the cylinder. If the
exhaust valve lift is reduced in the same way, it will be more difficult for the
exhaust gases to escape. Too much clearance also changes the time of
Cam Shaft
FIG. 238. — Adjustment of push rod clearance.
valve opening and closing, causing the valves to open late and close early.
If, on the other hand, this clearance is too small or entirely absent, the
valve will open early and close late, or will not close on its seat at all.
As the valve seats are lowered by continual grinding, the clearance is
gradually changed. For the proper operation of the valves, careful
attention should be given to this clearance space. Figure 238 illustrates
the clearance adjustment on the Overland car.
A weak spring on the exhaust valve may have a marked effect on the
AUTOMOBILE TROUBLES AND REMEDIES 219
operation of the engine. The exhaust valve then opens on the suction
stroke and burnt gases are again drawn into the cylinder.
(d) Valve Timing.— It is essential that the valves be properly timed
or set, in order to have the engine operated properly. The valves are
set at the factory and the necessity for adjusting the timing comes as the
result of wear on the valve seats, stems, rods, cams, half-time gears, or by
improper replacement of any of these parts. If the cam shaft has been
removed, care must be taken to get the gears properly meshed when re-
placing it. The gears are marked so that replacement is not difficult.
The proper method of replacing the gears on the Ford engine is shown in
Fig. 239. It will be noticed that there
is a prick-punch mark on one tooth of
the pinion and a corresponding mark
on the large gear. Before taking a
cam shaft out, an examination should
be made and if the gears are not so
marked it should be done before they
are disturbed.
If the clearances are properly ad-
justed for the push-rods and valve
stems and if the timing gears are
properly meshed, the valves should be
correctly timed, making allowance for
wear on the cam faces. Most engines
have the positions at which the valves
start to open and close marked on the
circumference of the flywheel. These FlG> 239.— Ford cam shaft setting,
points should be opposite the pointer, showing marked tooth and space on
usually at the top of the case, when il
the valves start to open and close. This time can be determined by
the use of a thin sheet of tissue paper. By placing a piece of the paper
in the clearance space between the push-rod and valve stem, one can
tell when the valve opens or closes.
Valve setting is an adjustment that should be made by an experienced
mechanic or one thoroughly familiar with the principles of the four-stroke
engine. The different makers have found by trial the settings that will
give the best results with their engines and cars. These settings differ
somewhat according to different conditions. If they are not marked
on the flywheel, they should be obtained from the manufacturer.
Figure 240 shows the approximate crank and piston positions for
the valve events. The inlet may be opened by the different makers, any-
where from top center to 20° of flywheel motion after center. The inlet
220
THE GASOLINE AUTOMOBILE
closes from 25° to 50° past lower center. The exhaust opens 35° to 60°
before lower center and closes from top center to 15° past center.
(e) Loose Piston or Scored Cylinder Walls. — A loose piston or scored
cylinder walls will cause a marked loss of compression. If the piston is
Inlet opens.
Inlet closes. Exhaust opens.
FIG. 240. — Valve setting diagram.
Exhaust closes.
not too loose, slightly larger rings may be put on. Sometimes the
blowing can be remedied by using a heavier cylinder oil. This will
to some extent remedy the trouble caused by scored cylinder walls,
although if too badly cut, they must be rebored and new pistons or
rings fitted in. Again, this is the work of
an experienced mechanic.
(/) Carbon Deposits in Cylinder. — After
the engine has been run for some time,
carbon deposits are liable to collect in the
cylinder . and on the pistons, especially if
too much lubricating oil or gasoline has
been used. The carbon deposit resulting
from too much lubricating oil is a sticky
substance, while that from too much
gasoline is hard, dry, and brittle. These
deposits, if allowed to collect, become hot
from the heat of explosions, and cause
preignition of the fresh charge of gas.
The best methods of removing carbon
deposit are to scrape it out or to burn it
out by means of an oxygen flame. The
latter method is quicker and by far the
FIG. 241.— Scraping the
cylinders.
most convenient. The following method is recommended by the Over-
land Company for the removal of carbon by scraping :
To scrape the cylinders, remove both inlet and exhaust valve caps.
Fig. 241, and turn the motor over until the pistons of two cylinders are at
their top centers. The scraping off of the deposit is done by means of
AUTOMOBILE TROUBLES AND REMEDIES 221
tools of different shapes, the tools being bent so as to reach the piston,
head and the sides and tops of the cylinders. Scrape all removed
carbon over to the exhaust valve and, when through, turn the motor until
the exhaust valve lifts, when the carbon may be scraped past the valve
and into the exhaust passage, whence it will be blown out. For a good
job, brush the surfaces clean and make sure that no carbon becomes
lodged between the exhaust valve and its seat. Finally wash with
kerosene.
In replacing the cylinder plugs over the valves, put graphite grease
around the threads; this will make a compression-tight joint and also
make it easier to remove the plugs the next time. Likewise, be sure to
replace the copper gaskets under the plugs.
It is an excellent plan to attend to removing the carbon and to grind-
ing the valves together at the same time.
Kerosene is also used for the removal of carbon from the cylinders.
Pour two or three tablespoonfuls of kerosene through the priming cocks
while the engine is warm. It has a strong solvent action on any gummy
binding material in the carbon and can be spread over the entire cylinder
by cranking the engine a few times around. Some motorists inject the
kerosene through the air valve of the carburetor just before the engine is
stopped preparatory to putting it away for the night. Kerosene will
not remove a hard carbon deposit but it will prevent it from forming if
used regularly about once a week.
Running the engine on alcohol for a few minutes is another device
that is sometimes used for burning out carbon deposits.
(0) Bearing Troubles. — The common bearing troubles are those caused
by the bearings becoming worn and loose, with a consequent knocking.
Faulty lubrication, clogged oil pipes and oil holes, and dirty oil are the
main causes of warm bearings. The bearings which are most liable to
give trouble are the wrist pin bearings, the connecting rod bearings, and
the main crank bearings. After a bearing has been excessively hot, it
should be refitted by a mechanic. A loose bearing can be tightened on
the pin by removing the liners or shims, or by being refitted.
154. Carburetion Troubles. — Improper mixture is the common source
of carburetor trouble. The mixture is either too rich, that is, too much
gasoline in proportion to the air, or too weak, that is, too much air in
proportion to the gasoline.
(a) Mixture too Rich. — A rich mixture shows itself by black smoke
coming from the muffler, and by overheating and missing of the engine.
Not only is fuel wasted, but the cylinders become fouled and carbonized.
A mixture too rich at slow speeds should be corrected by cutting down
on the gasoline, and at high speeds by increasing the auxiliary air. An
222 THE GASOLINE AUTOMOBILE
auxiliary air spring which sticks, a restricted air opening, or a flooded
carburetor will cause an overrich mixture.
(b) Mixture too Weak. — A weak mixture can be detected by back-firing
through the carburetor and by occasional muffler explosions. A weak
mixture, being a slow burning mixture, is still burning when the intake
valve opens for the following charge. This permits the flame to shoot
back through the manifold into the carburetor. A weak mixture should
not be confused with an improperly timed intake valve which opens
before the burning charge has been exhausted. If the intake valve has a
weak spring which does not close the valve properly, it may permit back-
firing through the carburetor. The explosions caused by the valve trouble
are usually more violent than a back-fire due to weak mixture. A weak
mixture at low speeds is caused generally by too little gasoline and at high
speeds by too much auxiliary air and the carburetor should be adjusted
accordingly.
An air leak in the manifold connections will dilute the mixture with air
and cause a weak mixture and back-firing. These leaks should be remedied
before the carburetor adjustments are changed.
A stuck or bent or obstructed gasoline needle valve may cause a weak
mixture by shutting off the supply of gasoline. The remedy is obvious.
(c) Color of Explosive Flame. — By opening the priming cocks on the
cylinders, the color of the flame can be seen as the explosive flame issues
out of the cocks. A blue flame indicates a perfect mixture, a red flame
indicates an excess of gasoline, and a white flame indicates an excess of air.
(d) Flooded Carburetor. — If the carburetor float becomes gasoline
soaked or filled with gasoline, it will not shut off the gasoline float valve
and the carburetor float chamber will become filled with gasoline. The
remedy is to take the float out and if it is made of cork, have it dried out,
painted with shellac and baked. If of the hollow metal type, have the
float emptied and the hole soldered. A small particle of dirt under the
float valve will also cause the carburetor to become flooded.
(e) Flooded Cylinder. — If the engine has been cranked for some little
time and too much gasoline has been sucked into the cylinders, the cylin-
ders become flooded with almost pure gasoline which condenses in the
cold cylinders. This charge will not explode. The remedy is to open the
priming cocks and crank the engine until the overrich mixture has been
expelled or diluted. The priming cocks can then be closed and the engine
will usually start. Flooding of the engine can also be caused by priming
the cylinders with too much gasoline. It sometimes happens that a
flooded engine can be started without difficulty after standing for several
hours. The excess gasoline has evaporated in the meantime.
(/) Cold Weather Starting. — In cold weather, when the engine is stiff
and the gasoline is hard to evaporate, it is necessary to inject a little
AUTOMOBILE TROUBLES AND REMEDIES 223
warm or high test gasoline into each cylinder through the priming cocks.
The carburetor may also be heated by the application of warm cloths.
The priming gasoline can be heated to advantage by placing a bottle of it
in a pan of hot water.
(0) Frozen Carburetor. — If there is water in the gasoline this water
may be frozen in the carburetor. The water, being heavier than the
gasoline, sinks to the bottom where it may freeze in cold weather. To
remedy this trouble apply hot cloths to the parts affected. Never use a
torch or flame of any sort around the carburetor.
(K) Feed System Stopped Up. — If, after priming, the engine starts
and suddenly dies down, the gasoline supply may be exhausted, the feed
pipe may be clogged, or a piece of dirt may have worked into the needle
valve. If there is a supply of gasoline and the trouble is found to be due
to dirt in the feed system, the feed pipe may be disconnected and the dirt
blown out. A particle of dirt in the needle valve may be removed by
screwing the valve shut and then opening it the proper amount. This
trouble and also the one due to water in the gasoline can be prevented by
straining the gasoline through a chamois skin before putting it into the
main tank.
(1) Loss of Pressure on Gasoline Tank. — It sometimes happens that
if a pressure gasoline system is used, the pressure becomes too low to
force the gasoline from the main tank to the auxiliary tank. This causes
a lack of fuel at the carburetor. A hand pump is usually furnished for
increasing this air pressure on the tank.
If the car is equipped with a gravity feed system, the gasoline may fail
to run to the carburetor when ascending a steep hill. It sometimes be-
comes necessary to back the car uphill, in which case the gasoline will
run to the carburetor without difficulty.
(j) Water Logged Carburetor. — It sometimes happens that the carbu-
retor becomes loaded with water, due to the fact that it can neither evapo-
rate nor get out. This water prevents the gasoline from getting in.
The water should be drained from the carburetor drain cock.
155. Ignition Troubles. — (a) Locating Defective Plug. — If one of the
cylinders is missing at all speeds, the ignition is at fault. The cylinder
can be located by opening the priming cocks and watching for the flame
to come out. The cylinder without flame, out of which issues only a
hiss, but no short report, is the one at fault. All of the plugs can be taken
out of the cylinders and, with the wires attached, placed on the cylinder
so that the threaded portions only are in contact. By turning the engine
over, the defective plug can be detected.
(fo) Defective Plugs. — A defective plug may be broken, oil soaked,
carbonized, or the air gap between terminals too much or too little.
If the plug is broken, it usually must be replaced by a new plug. A plug
224 THE GASOLINE AUTOMOBILE
with a loose center electrode may sometimes be repaired. If carbonized
or sooted up, the plug may readily be cleaned with a stiff brush and gaso-
line. Do not scrape with a knife, as it merely rubs the carbon into the
surface of the porcelain.
The gap between plug terminals should be between >^0 and %2 in.
It should not be more or less than this amount for efficient ignition. A
smooth dime is a good gage to use for setting this gap.
(c) Locating a Missing Cylinder. — If, after the plugs are found to be
in good order, one or more of the cylinders miss, the ones at fault can be
located by detaching the wire from the plug and holding the end about
34 in. from the plug binding post. A missing cylinder will show no spark,
and the trouble is due to a lack of secondary current in the wire to the
plug. Instead of detaching the wire from the plug, the current can be
short-circuited by placing the metallic part of a screw-driver in contact
with the plug binding post with the tip of the screw-driver about
J4 m- from the metal of the cylinder. As before, the missing cylinder
will show no spark. Lack of current at the plug may be due to defective
wiring, weak or run down batteries, poor adjustment of vibrator or
circuit breaker, engine out of time, and dirty or defective magneto
connections.
(d) Defective Wiring and Switches. — If there is no current at the
plug, the wiring system should be examined carefully for dirty and
loose terminals, broken connections, and oil soaked and wet wiring.
If the insulation has been worn off, the current is liable to be short-cir-
cuited or grounded through the engine or frame of the car. Defective
or poor contacts at switches may also be the cause of no current at the
plugs.
(e) Dry Batteries. — Weak or exhausted batteries are a common source
of trouble. If the batteries are suspected, they should be tested with a
small "ammeter." If any one of the dry cells shows less than 6 amp.,
it should be taken out and replaced with a new one. One weak cell will
greatly interfere with the operation of the others in the set. Occasionally,
a weak dry cell can be livened up temporarily by boring a small hole
through the top and pouring in a small quantity of water, or better still,
of vinegar. The effect is, however, only a temporary one.
Dry batteries should always be kept perfectly dry. If they become wet
on the outside, there is a tendency for the battery to be short-circuited
and exhaust itself. Especially is this true if water spills on the top of
the battery between the terminals.
(/) Storage Batteries. — If the storage battery appears dead or shows
lack of energy, it may be due to one of the following causes of trouble:
(a) discharged; (6) electrolyte in the jar too low; (c) specific gravity of
electrolyte too low; or (d) plates sulphated. These troubles are fully
AUTOMOBILE TROUBLES AND REMEDIES 225
treated in the chapter on starting and lighting under the heading of
Storage Batteries.
(g) Magneto Troubles. — If the ignition trouble has been located in the
magneto side of the system and the plugs and wiring system have been
found in good working order, attention should be turned to the magneto
itself. The distributor plate should be thoroughly cleaned with gaso-
line to remove any foreign matter which may have collected after con-
siderable use. After attending to this, it should be determined whether
or not the magneto is generating current. This can be done by dis-
connecting the magneto cables and watching the safety spark gap while
cranking the engine. If no spark appears there the trouble is in the
magneto itself.
The contact points may be pitted or burned. They should be filed
until they meet each other squarely. Be sure that the adjustment is prop-
erly made.
The carbon or collector brushes may be dirty or worn. They should
be cleaned, or if badly worn replaced with new brushes.
It occasionally happens that the magnets become weak or demagne-
tized. They may possibly be placed in the magneto in the wrong position.
If weak or demagnetized, they should be remagnetized before being re-
placed. Care should be exercised in getting the like poles of the magnets
together on the same side of the magneto. Most magnets are marked
with an "N" indicating the north pole.
(h) Coil Adjustments. — A frequent cause of no current at the plug is
coil trouble, especially where a vibrating coil is used for each cylinder.
The vibrator points become pitted, out of line, and burned, making good
contact impossible. The tension on the vibrator spring becomes changed,
permitting the coil to consume too much or too little current.
In the case of burned or pitted points, they should be filed flat with a
thin smooth file, or hammered flat with a small hammer. In either case
the points should be so shaped as to meet each other squarely.
If it becomes necessary to adjust the tension on the vibrators, the ten-
sion should be entirely taken off and gradually increased until the engine
runs satisfactorily without missing. It is very important to have all the
units adjusted alike. This can be easily done after a little experience.
The most accurate method of coil adjustment is with a coil current indi-
cator by which the amount of current consumed is measured. Coils
are built to consume about % amp. and the tension should be adjusted so
that the current consumption of each coil is not much greater than this
amount.
(i) Defective Condenser. — A sparking between the points of a vibrating
coil is due to dirty or pitted points, loose condenser connections, or a de-
fective condenser. If the latter, a new unit must be supplied,
226 THE GASOLINE AUTOMOBILE
(j) Breakdown of Wires or Insulation. — If no current is obtained in the
secondary of a coil, when the vibrator is working as it should, the trouble
is probably due to a broken wire inside of the coil. It sometimes happens
that the binding post wires become loose from the post just inside of the
coil. If only a slight spark can be obtained, the insulation on the inside
wire may be broken down, thus causing a short circuit of the current.
Obviously there is no remedy but to replace the coil.
(k) Timers and Commutators. — Trouble in the timer or commutator
usually comes from oil, water, and dirt which has found its way inside of
the housing, causing a short circuit. This foreign matter should be
cleaned out of the timer in order to have it give good service. After a
time, the contact points in the timer become worn and loose. New points
should be put in and all loose parts tightened. If the lost motion becomes
too great, it may be necessary to supply a new timer.
(1) The Spark Setting. — If the engine kicks back after cranking, the
spark is too far advanced an.d should be retarded so that the spark does
not occur until the piston has passed the dead center. The tendency of
an early spark on starting is to cause the engine to start backward. Too
early a spark at slow speeds will make the engine knock and will cause the
car to jerk.
A retarded spark causes the engine to overheat and lose considerable
of its power. There is no advantage of retarding the spark past center,
even in starting. When running it should be advanced in proportion to
the speed. , •
On cars equipped with automatic spark advance, the troubles due to
early and late spark are not experienced. Preignition from other causes,
however, may occur with either type of spark advance.
(m) Premature Ignition. — Premature ignition is caused by particles of
carbon, sharp corners, etc., becoming incandescent from the heat of ex-
plosion and igniting the charge on the compression stroke before the spark
occurs. Premature ignition occurs generally when the engine has been
loaded quite heavily at a slow speed, as when going up a steep hill on high
speed. Any engine will have premature ignition if it becomes excessively
hot under low speed and heavy load, but the tendency to preignite is much
more marked if the cylinder is full of carbon deposits. These carbon de-
posits should be cleaned out as explained before.
156. Lubricating and Cooling Troubles. — (a) Engine Lubrication. —
The usual lubricating troubles are those due to the use of the wrong kind
of lubricating oil or too much or too little of it. An engine with loose
fitting pistons requires a heavier oil than one with tight fitting pistons, and
an air-cooled engine usually requires a heavier oil than a water-cooled
engine. It is very essential that a true gas engine cylinder oil be used for
cylinder lubrication because it alone satisfies the requirements. Poor
AUTOMOBILE TROUBLES AND REMEDIES 227
lubricating oil is expensive at any price and it is good economy to use the
best cylinder oil obtainable. In this matter the recommendations of the
manufacturer should be followed out.
An excess of lubricating oil shows itself by a white bluish smoke com-
ing from the muffler. In addition to this, an excess of lubricating oil
causes the formation of a pasty carbon deposit in the cylinder, which causes
the engine to overheat.
The important things to look after are to be sure that there is a sufficient
supply of oil and that the oil pump is in working order. The crank case
should be drained and washed out with kerosene and new oil put in every
1000 miles.
(6) Poor Circulation. — Poor circulation in the cooling system is one of
the common sources of trouble and when neglected is liable to give the
motorist many uneasy moments. The water system must be kept filled
with water. This is of especial importance in the thermo-syphon
system, in which the water level must at all times be above the return
pipe from the engine to the radiator in order to have the circulation
continue.
A worn pump may cause poor circulation, because in most cases the
thermo-syphon effect in a forced system of circulation is not enough to
keep the water moving at the proper rate.
Sediment in the radiator and scale in the engine jacket may seriously
interfere with the circulation of the water. Such clogging of the system
comes from the continual heating and cooling of the impure water used.
This emphasizes the desirability of using pure water or rain water in the
radiator. The sediment and hard scale may be removed as follows:
Open the drain cock in the bottom of the radiator and introduce the end
of a hose in the filler of the radiator. Run the motor for about 15 minutes
and the fresh water from the hose will clean out the loose sediment or
scale in the water jackets and radiator. Through this process, a supply
of fresh water is constantly entering the system and passing through the
water jackets while the motor is running.
Next, dissolve as much ordinary washing soda as can be dissolved in
enough water to fill the radiator. Then run the motor with a retarded
spark until the water is brought up to the boiling point. Allow this solu-
tion to remain in the motor and radiator for several hours, after which
again open the drain cock and, with a hose, again flush out the entire
system with fresh water as before. In extreme cases it would be well
to repeat this process several times. The final operation of flushing out
with fresh water should be thoroughly done. If any of the washing soda
solution is left in the motor or radiator, it may result in undesirable
chemical action.
When rubber hose forms a part of the circulating system, a kink or
228 THE GASOLINE AUTOMOBILE
twist in the hose may possibly cause poor circulation of the water. The
inside fibers of the hose also tend to come loose and clog the system.
In the case of thermo-syphon cooling systems or in air-cooled motors,
the operation of the fan is essential to the successful operation of the cool-
ing system. If the fan belt breaks or slips, or the fan blades are bent, the
air circulation through the radiator is interfered with and consequently
the water is not properly cooled.
The attention which must be given to the cooling system in winter to
prevent freezing has been thoroughly taken up in Chap. V. One thing
to be watched in winter running is the temperature of the water. If the
weather is excessively cold, the water may be cooled below the efficient
running temperature of from 180° to 200°. In this case, the radiator
front should be partially covered in order to keep out a part of the cold air.
This will also keep the water warm for a longer time when the car is
standing.
157. Starting and Lighting Troubles. — The troubles ordinarily ex-
perienced with the starting and lighting systems are taken up in the chap-
ter treating of those subjects.
158. Transmission Troubles. — (a) Clutch Slips. — Clutch troubles are
about the same in either the cone, plate, or multiple-disc types. The
clutch either slips, engages harshly, grabs, or refuses to release. If it
slips, the full power of the engine is not transmitted and the clutch becomes
hot from the friction. In the cone and dry-plate types, a coating of oil
on the facings will cause slipping. The wear of the facing or weak or
broken springs will cause the same results. If the slipping is caused by
grease and dirt, the clutch leather should be thoroughly cleaned with a
rag dipped in kerosene.
(6) Clutch Grabs. — If the clutch engages harshly or grabs suddenly, it
may be due to the drying out or hardening of the clutch leathers. A dress-
ing of the facing with neatsfoot oil or castor oil will make it soft and permit
gradual engagement. If the clutch springs are too tight, the clutch will
"drag" and burn the leather facing.
If a multiple-disc or plate clutch is designed to work in an oil bath, it
will engage harshly or grab if the plates become dry. The clutch will also
fail to disengage when the pedal is pressed down.
(c) Change Gears Stick. — If the change gears stick when attempt is
made to shift from one gear to another, the shifting members may be
stuck on the shaft. If the gears have become burned or teeth broken out,
the particles of metal may prevent the movement of the sliding member.
Occasionally the shifting lever becomes stuck and refuses to operate the
gears. Under ordinary conditions, the change gears should give very
little trouble if due attention is given to the lubrication and care to their
shifting in operation.
AUTOMOBILE TROUBLES AND REMEDIES
229
(d) Differential Troubles.— A noisy differential and driving gear is due
to dirt, lack of grease, or broken or worn teeth. In some cases wear can
be taken up by the proper adjustments, but these should always be made
by an experienced mechanic. The differential, as a rule, will give very
little trouble. A break in the differential or in its connections to the
wheels is made evident by failure of the engine to propel the car. If the
connection to either wheel is broken the other wheel will also lose its power.
159. Chassis Troubles. — (a) Faulty Alignment of Front Wheels.— Most
of the front wheel trouble is due to faulty alignment. The following
instructions are given for the adjustment of the front wheels and bearings
on the Overland car: The front wheels, when correctly aligned, are not
exactly parallel, but "toed-in" (Fig. 242). To test their proper align-
ment, jack up both front wheels and with a piece of chalk or a lead pencil
FIG. 242. — Toed-in and cambered front wheels.
held in a fixed position against the tire spin the wheels, drawing a line
around the tire casing. The distance between the lines measured at the
front of the wheels should be from % to ^ in. less than in the rear.
"If a steering knuckle is bent, it is best to replace it with a new one,
because bending it cold will not always restore its correct shape, while
heating it may make it too soft for safety.
"If faulty alignment is due to a bent steering cross-rod, it may be
straightened out and then adjusted by loosening the lock-nut and screw-
ing the rod in or out of its yoke end. Be sure to lock the nut tightly
after adjusting.
"The front wheels are also 'set,' or 'cambered/ so that the wheels are a
little closer together at the bottom than at the top. This arrangement is
desirable on account of the fact that the front wheels are 'dished' so as to
make the wheel a sort of flattened cone. This 'dish' of the wheel is com-
pensated by the 'camber/ by which means the lowest wheel spoke is in a
vertical position with relation to the road surface. The combined 'toe-
ing-inr and 'cambering' makes for greater strength and also reduces mate-
rially the effort required in steering the vehicle. The camber is sequred by
inclining the axle spindle from its central line, and no adjustment is re-
quired in connection with it.
230 THE GASOLINE AUTOMOBILE
"To see whether the front wheel bearings need adjustment, jack up
the wheels. Any looseness will show on rocking the wheels sideways.
To tighten the bearing, spin the wheel, at the same time screwing down the
adjusting nut until the bearing is so tight that it will stop the rotation of
the wheel. Then back off the nut only enough to allow the wheel to spin.
Lock in this position and the bearing will give the best service.
"In general, a somewhat loose bearing is to be preferred to one that is
so tight that the rollers are likely to become injured."
(b) Loose Steering Gear. — With continued use, the worm or screw in the
steering gear will wear, and a looseness of the wheel will result. Means
are usually provided for taking up this wear. Most drivers prefer to have
a small amount of lost motion (about % in.) in the wheel, as it makes
steering easier and relieves the steering gear from all the road shocks.
A great deal of steering gear trouble and wear can be avoided by oiling
all the joints regularly. This important point is too often neglected.
(c) Brakes. — It is very necessary that the brakes be kept in perfect
working order at all times. It is more necessary to be able to stop the car
in emergencies than to start it. If the brakes fail to hold, it may be that
the drum and band facings have become covered with oil and dirt, or
the band facings may be worn. In the latter case, new facings are neces-
sary in most cases, but adjustments can be made for slight wear.
The brakes may bind or stick, due to the tight adjustments. With
tight adjustments, the motor is pulling the car against the friction of the
brakes at all times.
If the brakes are not adjusted the same on each side of the car, there
will be a tendency for the car to skid when the brakes are applied. The
braking effect comes on only one wheel and this tends to swing the car
around. Many cars are provided with brake equalizers which allow
them to work together.
(d) Springs. — After a car has been run for some little time, the spring
clips become loose and the conditions are then ideal for breaking the
springs. Spring breakage occurs mostly with loose clips. Consequently
these clips should be tightened every once in a while.
When springs are not lubricated, water works its way in between the
leaves and causes them to rust, often to such an extent that they become
almost like solid pieces. This causes them to lose much of their spring
action. It is a good plan to jack up the frame of the car occasionally,
so as to take the weight off the springs, and insert oil and graphite
between the leaves. It is also a good plan, about once a year, to have
all the springs taken apart, the surfaces thoroughly cleaned and coated
with a thick mixture of oil and graphite.
CHAPTER X
OPERATION AND CARE
160. Preparations for Starting. — Before starting an automobile en-
gine, the driver should make sure that there is plenty of gasoline in the
tank and that it is turned on so as to flow to the carburetor. The radiator
should be filled with clean water, free from lime or other form of matter
that will have a tendency to coat the inside of the radiator when the water
evaporates and thus prevent cooling action. Rain water is best. The
driver should also be sure that he has plenty of lubricating oil. In starting
the engine, close the switch on the battery circuit, or, in some cases, where
a high tension magneto is used, the engine may be started on the magneto.
It is better, though, in most cases, to use the battery circuit, as the cur-
rent there is always available. The change speed lever should be in the
neutral position. If the lever is so that the gears are meshed, cranking the
engine would start the car in motion, and engines that pick up easily are
liable to start and run away, especially if the gear shift lever is in the first
position. It is also advisable to have the emergency brake set. This
will quite often prevent runaways. The spark lever should be retarded,
and the throttle lever slightly advanced before cranking the engine. As
soon as the motor starts, advance the spark lever about two-thirds of the
distance around the quadrant, and retard the throttle lever so that the
motor will not race.
161. Cranking. — In cranking the engine, always set the crank so as to
pull up. In this manner, should there be a back-fire the crank will be
pulled down out of the hand; whereas, if one is pushing down on the crank,
the back-fire will be very liable to cause injury to the driver's wrist or arm,
as he would be unable to get away from it.
After an engine has been standing for some time, it is quite probable
that it will not get gasoline at once, due to the gasoline evaporating or
leaking from the carburetor. In order to have sufficient gasoline in the
mixing chamber, it is customary to raise the float, which allows the gaso-
line to overflow into the mixing chamber. This process is commonly
called " priming" or "tickling" the carburetor and insures a rich mixture
in starting.
This may also be accomplished by opening the priming cocks on the
cylinders and pouring a few drops of gasoline directly into the cylinders.
If there are no priming cocks on the cylinders, one can use a priming spark
plug.
25 231
232 THE GASOLINE AUTOMOBILE
162. How to Drive.— There is "good form" and "bad form" in driv-
ing a car the same as in doing anything else. One-half the pleasure of
motoring comes from knowing how to drive easily. Proper driving also
means minimum strain and wear on the car. It prevents unnecessary
stress and wear on the motor and transmission system, and saves the gaso-
line and oil. In starting the automobile, the object is to have the car
pass from a stationary position into rapid motion with the least amount
of stress on the motor and transmission, and also with the most comfort
to the occupants of the car. In doing this, a steady pull should be main-
tained on the driving mechanism from the point where the driver lets in
the first speed until the car is under full headway. Starting with a jerk,
FIG. 243.— Shifting gears.
or passing unevenly from one speed to another, strains the motor, racks
the frame, and causes various troubles in the driving mechanism.
Having started the engine with the gears in the neutral position, the
proper method of gear shifting is as follows:
Advance the spark lever about two-thirds of the way around the
quadrant, throw out the clutch, and throw the speed change lever in the
first position, as shown in Fig. 243. Let the clutch in easily but firmly
and increase the motor speed gradually, either by the foot accelerator or
by the hand throttle, until the motor picks up the load. Try to acceler-
ate the engine as the clutch is let in. The mechanical act of shifting gears
is very simple, but the knack of learning to perform the operation rightly
takes practice. As you engage the gears for any speed and begin to let in
the clutch, give the motor more gas at the same time. Once you have
learned to do this properly, you will never have to give it a thought.
OPERATION AND CARE
233
In changing from first to second speed, release your foot accelerator or
throttle hand lever, then throw out the clutch, change to second speed,
and again let in the clutch, at the same time accelerating the engine again.
Repeat the same operation on going into higher speed.
Just before shifting gears, the engine should be throttled by removing
the foot from the accelerator, so that the two gears which are going to be
meshed are running at the same speed. This permits a smooth shifting
of gears, and also prevents the motor from racing. Then as the clutch is
let in the engine should be accelerated to give it sufficient power.
When the car is in high speed, assume a comfortable easy position.
Do not sit sideways in the seat nor take your hands from the steering
wheel. If one sits in an easy upright position, driving does not become
tiresome, and it also gives a person better control, as he does not have to
move from his position in order to operate any of the levers. Also, an
erect and alert driver makes a better appearance than one who slouches
in his seat and handles his car carelessly.
FIG. 244. — Emergency stop.
163. Use of the Brakes.— The operation of stopping a car smoothly is
just as important as knowing how to start. The best results are obtained
by beginning to pull up your car early enough, so as to apply your brakes
gradually, thus bringing the car to a stop without straining the mechan-
ism or jolting the passengers. Do not wait until you are within a few
feet of the stopping place and then have to use the emergency brake or
jam the brakes down hard. Applying the brakes hard is not only an
unnecessary strain on the mechanism, but is very hard on tires since,
when the wheels stop, the road acts as a file on the tires.
234 THE GASOLINE AUTOMOBILE
Sometimes it is necessary to make an emergency or quick stop. In
doing this the operator does not take time to slow down his engine, but
presses both foot pedals and applies the hand emergency brake at the
same time, as shown in Fig. 244. In pressing both pedals, he releases the
clutch and applies the service brake, and the braking effort is further
increased by the application of the emergency brake.
In descending steep hills, it is often convenient to use the engine as a
brake. This can be done by closing the throttle and shutting off the
spark. Then by leaving the clutch in, the car is forced to run the engine
against compression without receiving any power from it. The gear
shift lever may be left in either high, intermediate, or low speed. In the
low speed position the engine will have more of a braking effect than in the
high speed position, because it must be turned much faster for the same
speed of the car. If the grade is long and steep, use the foot and emer-
gency brakes alternately. This equalizes the wear on them.
164. Speeding. — When running a new car, do not speed it up until
you are absolutely sure of your ability to drive. Furthermore, any new
piece of machinery should not be run at high speed for any length of
time until its bearings have had a chance to wear to a smooth fit. A few
miles of racing are harder on the bearings of a car than several days of
moderate driving.
165. Care in Driving. — All cars have low and intermediate gears for
use in starting, hill climbing, and bad roads. A good rule to follow in
shifting gears is to shift just before you need to in climbing hills. To
attempt to climb every hill on high speed always marks the amateur
driver. The intermediate gears should be used on steep hills, even if they
could be climbed on high speed. If it is desired to climb a hill on high
speed, one should take a running start and rush up the hill. In going over
bad roads, it is better to shift into second or first speeds immediately.
This will save slipping the clutch, which is a bad practice. On the
lower speeds, one can control the speed of the car entirely by the use of
the throttle.
In going over bridges, cross-walks, railroad tracks, or water-brakes, it
is better to strike them- at an angle than to hit them squarely. This
method throws the strain on the springs successively instead of all at
once and reduces the rebound of the car. In going through sand, it is
better to let the car pick its way and not try to hold it in line and force it
to make a new track. For this reason a little play in the steering gear is
desirable.
One of the first things that a new driver learns is the advantage to be
derived from consideration and courtesy extended to others using the
public highway. Most drivers know that they are expected to turn to the
right when approaching a vehicle, or to the left in overtaking and passing
OPERATION AND CARE 235
a slow-moving vehicle going in the same direction. In meeting another
car at night, dim your headlights so that they will not confuse the other
driver.
After they have begun to realize the accuracy with which a car
may be steered and the ease with which it may be called upon to pass
another vehicle, possibly approaching from the opposite direction, it
seems natural for some drivers to display their nerve in not turning from
the center of the road until they are almost upon the approaching vehicle.
Often, however, the other fellow has as much courage and takes the same
stand, and in the confusion which very frequently follows, either one or
both cars are damaged on account of collision.
In passing vehicles which are approaching, as large a margin of space
as possible should be afforded, and in passing a slow-moving vehicle
ahead, pass it as quickly as possible and without cutting in short ahead
of it.
166. Driving in City Traffic.— The lack of consideration on the part of
a few careless drivers has resulted in the adoption of very strict muni-
cipal regulation governing traffic. Those who are familiar with city
traffic regulations and apply them as well on country roads, will not be
likely to encounter difficulties.
The burning of at least three lamps, including two head or side and one
tail lamp, is enforced from sun-down to sun-up in practically every state.
FIG. 245.— Turning to the right. FIG. 246.— Turning to the left.
In approaching an intersection, either in the city or in the country,
where a clear vision of the road approached can not be had because of
buildings, fences, etc., which obstruct the view, the car should be slowed
down to a speed at which it can be readily stopped in case of the approach
of another vehicle from either side.
In turning into another road to the right, the driver should keep his
car as near the right-hand curb as practicable, as shown in Fig. 245.
In turning into another road to the left he should turn around the
center of the two and as in Fig. 246. No vehicle should be slowed or
stopped without the driver thereof giving those behind him warning of his
intentions to so do, by proper signals.
Often drivers of horse-drawn vehicles become confused if their horses
are frightened by the approach of an automobile and in drawing up the
236 THE GASOLINE AUTOMOBILE
horses sharply to one side the animals are liable to jump or rear, with the
result that the vehicle may be overturned and the automobile injured as
well. In cases of this kind, it is better to stop the machine entirely and,
if necessary, even stop the motor.
More accidents result from unwillingness to change gears than from
almost any other cause. Most American drivers use their first and sec-
ond speeds only in starting their car. They allow the car to drift along
and thus get into a tight place in traffic or too close to street cars and, be-
cause of misjudging the speed of the approaching vehicle or their selfish
desire to crowd out another car, collisions or other accidents frequently
result. It is a simple operation to change from third to second speed.
It increases the power and affords the possibility of a great deal quicker
acceleration as well. The second speed is incorporated for a purpose.
It is seldom that we are in such a hurry that we can not spare a moment to
afford absolute safety.
Accidents are not due to one's losing control of the car in many
instances, but are more likely due to one's losing control of himself.
One is not an expert driver until he intuitively performs the operations
which control the car just as one walks or reaches out for an object.
167. Skidding. — When traveling on slippery roads, avoid making
sudden turns; also avoid sudden application of the brakes or sudden
changes of power, as they all tend to cause skidding.
Most skids can be corrected by the manipulation of the steering and
brakes. An expert driver can keep his car straight under almost any
conditions, but it is impossible to explain just how he does it, except that
he knows his car and becomes almost a part of it. Usually the rear end
skids first, and in the right hand direction, this being caused by the crown
of the road. Under such conditions, the skidding action will be aggra-
vated if the brakes are applied, and the car may be ditched or continue
to skid until it hits the curb.
The correct action in an emergency of this kind is to let up on the
accelerator pedal and thus to reduce the power to a point where the wheels
are rolling freely without either being retarded by the brakes or drawn
ahead by the engine. If the car recovers its traction, the power may be
applied gradually and it will be advisable to steer for the center of the
road again. However, if the car continues to skid sideways, steer for the
center of the road, applying the power gently. This will aggravate the
skid for the moment, but will leave you with the front wheels in the center
of the road and the car pointing at an angle. By so doing, you can
mount to the crown of the road again and the momentum of the car will
take the rear wheels out of the ditch on the right hand side. It is cus-
tomary to advise turning the front wheels in the direction that the car is
skidding in order to correct the action, but this can hardly be said to be
OPERATION AND CARE 237
advisable in most cases, as the amount of room on the skidding side is
somewhat limited, and for this reason the explanation given above will
better apply to such a condition.
When turning a corner on wet asphalt pavements it frequently occurs
that the front wheels skid. In a case of this kind, immediate action is
necessary. It will be found that by applying the brakes suddenly for a
moment so as to lock the wheels, the rear end of the car will skid in the
direction in which the car is to be turned. This will help the action of
the front wheels and the releasing of the brakes and the touch of the
accelerator will bring the car around the corner without any over-travel
of the front end. By applying the brakes in this way, it is possible to
turn the front wheels in the direction opposite to that which the car is
to be turned for a moment while the rear end is skidding. When the
brakes are released, it is plain to see that the front wheels will have no
tendency to skid farther, as they will be pointing in the direction which
the car is to be turned and the rear end will be in line with it, due to
the skid.
Needless to say, this manipulation requires a little more expertness
than the correction of an ordinary skid on a straight road.
Skidding can be prevented and accidents avoided, also the life of
the tires lengthened, if one will learn how to turn his car out of street
car tracks and ruts. Make a sharp turn of the front wheels. Do not
allow the wheel to climb along the edge of the rut and finally jump off
suddenly, and do not attempt to climb out of these conditions at speed.
Driving a car around a sharp corner at 25 miles an hour does more
damage to the tires than 15 or 20 miles of straight road work. This is
an economical reason why one should drive around corners cautiously
and slowly. The other reasons are obvious.
The natural inclination of the driver is to throw out the clutch in
coasting down hill or driving over rough roads. This should not be done.
Keep the motor pulling the car over rough roads. Thus it keeps every-
thing taut and lessens the shock and jar that the car gets through
bumping over ruts.
168. Knowing the Car. — One will very soon become accustomed to
all of the noises the car makes, and any strange sound, be it ever so slight,
will be immediately perceptible.
Much of the satisfaction that an automobile gives depends upon the
driver. If he neglects his automobile, if he does not lubricate it, or if
he tinkers with it too much, he is bound to receive unsatisfactory
service.
No machine can be absolutely automatic. All things must wear in
time. The best preventive of wear, and the most certain thing to increase
the life of an automobile, is proper lubrication. Remember that a motor
238 THE GASOLINE AUTOMOBILE
car is like any piece of machinery and will not keep in good running con-
dition without a reasonable amount of care. The life of a car can be cut
in two by neglect or doubled by careful use.
One should familiarize himself thoroughly with all the lubricating
points of the car. The chart in Chap. V will show where each one is lo-
cated. Make the lubrication of the car as regular as the eating of meals.
If one does this he will not have any complaint to make of his car becom-
ing noisy or of bearings wearing out. If he does not do it, he will not get
the satisfaction from his car that he expects. Satisfaction would be
greatly increased if everyone would learn the details of his machine, that is,
learn to make the simple examinations and adjustments. Do not depend
on some one else to do that which is so simply done and which one can get
much satisfaction in doing. One should familiarize himself with every
detail of his car and then he will have great confidence in venturing over
any road at any distance from a repair station.
In learning to drive a car, it is better to use the hand throttle for the
first few days until you have mastered the other details of driving. Then
learn the use of the foot accelerator. The foot accelerator is controlled
by a spring and is released by removing the foot. This will slow down the
car to the point where the hand throttle is set. In using the foot
accelerator, keep the hand throttle set at a point where the engine
will just pull the car. Then, when the foot is removed from the
accelerator, there will be no danger of an accident from the car's not
slowing down.
Never allow the motor to race when it is idle. "When there is no load
on the engine it will vibrate unduly at high speeds, which causes exces-
sive strains and makes the engine and car noisy. Racing the motor
when driving can be avoided by learning to use the foot accelerator in the
proper manner in relation to the clutch and gear shifts.
169. The Spring Overhauling. — The greatest trouble with the average
motorist is that he has the idea that all the attention a car needs is to
keep it full of gasoline, oil, and water. There are many owners, however,
who enjoy making their own adjustments and keeping their car always
in good condition by giving it frequent attention. After a car has been
laid up for some time the oil is forced out of the bearings and, if run in
this condition, considerable damage is liable to result. All old oil should
be drained off and the case thoroughly washed out with kerosene. Hot
kerosene and oil should be poured into the cylinders to cut the gummed
oil and to remove any rust that may have formed. After draining off
the kerosene, the crank case should be filled with oil to the upper test
cock. Do not use the electric starter until you are sure that the motor
is free to turn. Better turn the motor over a few times with the hand
crank first. Clean the spark plugs by washing with gasoline and a
. OPERATION AND CARE 239
brush — never scrape them, then adjust the spark gap between points
to about 3^2 in. or the thickness of a well worn dime.
Test for leaks around the valves and spark plugs by squirting oil on
the joints and then turning the engine over. If there are any leaks, air
bubbles will be seen in the oil.
If the gasoline does not flow to the carburetor, remove the feed pipe
and blow it out; also clean the screen in the bottom of the carburetor.
The gasoline flow can be tested by holding down the float.
In the wet type multiple-disc clutches, the oil should be drained off
and then they should be filled with kerosene. Replace the plug and
start up the motor. Let the motor run for a few minutes during which
time push the clutch in and out several times. Then stop the motor,
drain off the kerosene, and fill with the proper amount of lubricant. The
transmission, differential, and universal joint should also be washed out
and repacked. Every point mentioned on the lubrication chart of
Chap. V should be cleaned, adjusted and oiled.
Electrical System. — Remove the rotor and clean its bearings with gaso-
line and a cloth, then rub a little vaseline on the race very lightly. Clean
the breaker points with a fine piece of emery cloth and set the gap to the
width of the gauge, or about ^4 in. See that all wiring connections are
tight and free from corrosion. It is a good plan also to put in new dry
cells and be sure that they are connected up properly.
The storage battery is probably the most delicate part of the car and
should receive very careful attention. It is advisable to give the battery
a long overcharge at the beginning of the season, especially if the car has
been laid up for some time.
During the out-of-season period, rust will accumulate in the radiator
and engine jacket, and should be cleaned out. To do this, drain out the
anti-freezing solution and fill the radiator with a solution of soda and
water. With this solution in the cooling system, run the motor for about
10 minutes and wash out the system, following the instructions of Art.
156(6), Chap. IX.
The leaves of the springs should be spread apart and a mixture of oil
and graphite inserted.
If the tires have been removed for storage, see that a thorough appli-
cation of soapstone is applied to the inside of the rims to prevent their
sticking to the tires.
An easy way to calculate pressure for tires is to multiply the diameter
of the tire in inches by 20. For example, the correct pressure for a 3-in.
tire is 60 lb., and for a 4-in. tire, 80 Ib. A tire should be pumped up till it
becomes perfectly round when supporting the weight of the car. Of
course the only sure way of getting the correct pressure is with the use of
a reliable pressure gauge.
240 THE GASOLINE AUTOMOBILE
170. Washing the Car.— The car should be washed before the mud has
a chance to dry. If a hose is used, the stream should be tempered or,
better still, the nozzle should be taken off the hose and a slow stream
used. Always use cold water, as warm water will injure the varnish.
After hosing off the mud, take a sponge well filled with water and gently
dash it against the surface. Never rub the surface when washing, as it is
sure to scratch the polished surface.
After the mud has been removed, remove any grease from the finish by
washing with suds of a pure white soap. This should be done with a
soft sponge and as little rubbing as possible. After soaping, rinse with
cold water, rub dry, and polish with a chamois skin. Do not have the
car standing in the bright sunlight, for it will dry too rapidly and be
streaked.
A new car should be washed with cold water before it gets dirty. The
cold water will help to set the varnish and prevent the accumulation of
dust.
Cleaning the Reflectors. — When lamp reflectors become dirty do not
wipe them, but use a stream of cold water to remove the dust or dirt
and permit the reflectors to dry by air only. The reflectors are silver
plated. The silver becomes scratched when the reflector is wiped, even
with very soft material. If reflectors become dull after long service, they
should be polished by using chamois with a light application of red rouge
or crocus. The chamois should be very soft and free from wrinkles. If
a wad of cotton or waste (about the size of an egg) is placed within the
chamois, a smooth surface for wiping can be obtained. Red rouge or
crocus is used by j ewelers for cleaning watch-cases. When properly placed
on chamois, it will not scratch the reflector. Moisten the chamois
with alcohol, then apply the rouge or crocus to the chamois and wipe the
reflector with a continuous rotary motion, but do not press too hard.
The polishing marks will be very noticeable if other than a rotary motion
is used. The efficiency of old reflectors will be increased if they are silver
plated. This should be done by a lamp manufacturer or a reliable
silver-plater.
171. Care of Tires. — The following few suggestions will apply to
pneumatic tires in general. The various sizes of tires are constructed
for the purpose of carrying up to certain maximum loads and no more.
Owners should realize, therefore, that overloading a car beyond
the intended carrying capacity of the tires is sure to materially shorten
their life.
Do not turn corners or run over sharp obstructions, like car tracks,
at a high rate of speed. Such practice is sure to strain or possibly
break the fabric, with the result that the further life of the tires will be
OPERATION AND CARE 241
limited. Remember that most tire troubles are the result of abuse more
than use.
In case of puncture the car should be stopped at once and the tube
repaired or replaced. The tire should also be examined carefully and the
cause of the puncture ascertained, and the nail, glass, or whatever it may
be, should be extracted. Before replacing the tire on the wheel, examine
the inside of the casing to see that the cause of the puncture is not still
protruding, because, if allowed to remain, it would continue to cut the
inner tube. It is also advisable to look over the outside of your tires fre-
quently and take out any pieces of glass or other particles which may
have become imbedded in the casing, as they are liable to work themselves
in and finally puncture the inner tube.
A puncture, gash, or cut sufficiently deep to expose the fabric should
have a vulcanized repair made without delay. Otherwise, water and dirt
will soon ruin the whole tire, the threads acting as a conductor for the
moisture, the fabric thus becoming rotted.
A bruise is an injury to the carcass of a tire caused by violent contact
with an irregularity which tears the fabric. Usually the injury does not
show at once. However, the structure of the tire is permanently weak-
ened at the injured spot, and eventually a blowout will occur. Even
the most careful and skillful driver cannot avoid bruises altogether. But
if your tires are properly inflated and you strike an obstruction, the tire
has the resiliency of the air behind it to aid in resisting the impact of the
blow and the effect is likely to be less serious.
Experience has taught the careful driver to carry one or more spare
tubes, as a cemented roadside repair will not always hold, especially in
warm weather, as the heat generated in the tire may loosen the patch.
When touring, a spare casing should always be carried. It should be
strapped tightly to the tire holder, otherwise it will chafe.
Spare tubes should be kept lightly inflated. This keeps them in good
condition and prolongs their life. They should not be stored in a greasy
tool-box under any circumstances.
Excessive weight on a casing will break down the fabric in the side
walls, and if persisted in, a blow-out is apt to result. When this occurs,
the casing is likely to be so badly damaged as to be beyond repair. If
your roads are very rough and stony, or if you are carrying heavy weights
in your car, it is better to equip the car with a set of extra-size tires.
You can get larger tires which will fit your rims.
Pneumatic tires are designed to carry loads in proportion to their cross-
sectional area and diameter. They should never be overloaded. Fol-
lowing is given a table of the various tire sizes and the weight each tire
should carry. Weigh the car, and if the tires are carrying more than
their rated load put on larger tires.
242
THE GASOLINE AUTOMOBILE
Size of tires
Load per wheel in
pounds
Size of tires
Load per wheel in
pounds
2^ in. all diam.
225
30 X 4 in.
550
3 in. all diam.
350
32 X 4 in.
650
28 X 3M in.
400
34 X 4 in.
700
30 X 3K in.
450
36 X 4 in.
750
32 X 3^ in-
550
32 X 4K in.
800
34 X 3^ in-
600
34 X 4H in-
900
36 X 3^ in.
600
36 X 4^ in.
1000
All 5 in.
1000 or over.
If the car is not used during the winter, it is better to remove the tires
from the rims, keeping casings and tubes in a fairly warm atmosphere
away from the light. It will be better to slightly inflate the tubes, as
that keeps them very nearly in the position in which they will be used later
on. Before the tires are put back, the rim should be thoroughly cleaned
and any rust carefully removed; a coat of paint or shellac is also advised.
If the tires are not removed and the car is stored in a light place, it
will be well to cover the tires to protect them from the strong light, which
has a deteriorating effect on rubber.
The greatest injury that can be done to tires on a car stored for the
winter is to allow the weight of the car to rest on the tires. The car
should be blocked up, so that no weight is borne by the tires, and the
tires should then be deflated partially. This will relieve the tires of all
strain, so that in the spring they should be no worse for the winter's
storage.
Extra casings carried on the car should be covered to protect them from
the sunlight, which has an injurious effect on rubber. Do not place your
extra tubes where they will come into contact with tools or oil. Carry
the tubes in a tube bag. It is a good plan to tie a piece of cloth around
the valve stem before placing the tube in the bag. This will prevent the
possibility of the stem injuring the rubber.
Bear in mind that heat, light, and oil are natural enemies of rubber.
When grease comes into contact with your tires, it should be removed
immediately with gasoline.
Fast driving and tire economy have absolutely nothing in common.
High speed and high bills for tire maintenance usually go hand in hand.
It stands to reason that the wear and tear on tires is far greater when a car
is driven at a high rate of speed than when it is used at a moderate pace.
In addition to the increased force with which a wheel strikes an obstruc-
tion, when rolling at an excessive speed, fast driving generates increased
heat in your tires, causing disintegration.
Shifting Tires— Tires that show wear on one side from use on rutty
OPERATION AND CARE
243
roads or from driving in car tracks should be turned around. It is also
a good plan to place the rear tires on the front wheels when they begin to
show age. Rear tires carry more than half the weight of the car, get the
roughest usage, and are also the driving tires, so that they naturally wear
more rapidly than the front tires, which are simply subject to a rolling
action and usually sustain less weight. A sprung axle will often cause
quick wearing of a tire, for the reason that the tire is running at an angle
with the direction of the car. This necessarily sets up a sliding and scrap-
ing on the road surface. If the surface of one tire looks as if it has been
sandpapered, examine the alignment of the wheels.
FIG. 247. — Broken fabric.
172. Tire Troubles— Broken Fabric.— On the inside of the casing
shown in Fig. 247 will be noticed a break in the fabric. This is the result
of the blow received by the tire in hitting a stone, rail, or something of
that sort at high speed. While no permanent mark may be left on the
outside of the tire, especially if the object is smooth and blunt, the fabric
inside may give way under the abnormal strain of such a blow. This does
not indicate that the tire was in any way defective.
Sometimes a tire may be run weeks after the fabric is broken from the
244 THE GASOLINE AUTOMOBILE
bruise before the blowout occurs. It has even happened in a garage, with
the car standing still. Sometimes the break will exist only in a few of the
plies of fabric, which will pinch the inner tube, allowing the tire to deflate
gradually.
Blowouts.— Few people realize the tremendous pressure tending to
rupture a tire and the consequent great strength that must be given any
repair that is to be effective. This is especially true in cases of blow-
outs. Figure 248 shows a tire that has blown out due to ineffective repairs.
FIG. 248.— Blow-out from ineffective repairs.
It originally had a small cut extending clear through the casing. An in-
side patch, applied by the owner, did the tire more harm than good. The
result, as shown in the picture, was that the pressure forced the patch
through the hole, the patch wedging the fabric apart and causing it to
break almost from bead to bead. The inside view shows how the patch
has been pulled away from its original position and has been forced through
the break. This condition results from the tire not receiving the proper
attention when first cut. An inside protection patch, used with an out-
side emergency band to take the strain at the weakened point, should be
used until permanent repairs can be made.
OPERATION AND CARE
245
Skidding.— Skidding, or sliding the wheels by too great a brake pres-
sure, has a disastrous effect on tires. Dragging the wheels for even a
short distance over a hard rough surface will grind off the tread and even
go through several thicknesses of fabric. There is nothing to be gained
by sliding the wheels. Learn to apply the brakes up to the point where
the wheels will just turn and no farther. The braking effect will be just
as great or even greater than if the wheels are skidded.
FIG. 249. — Rut-worn tire.
FIG. 250. — Tire injured by chains.
Running in Ruts. — No tire will stand the wear from continued running
in car tracks or ruts.
Figure 249 shows a tire worn off on the sides, commonly called "rut-
worn." The same condition will result if a tire is run on muddy roads
that have a frozen crust insufficient in thickness to support the car, so
that the tire in breaking through is bound to be gouged off in the manner
shown. This condition also results from running close to and rubbing
246 THE GASOLINE AUTOMOBILE
against curbstones. A similar condition, but nearer the tread, is caused
by running in car tracks.
One can readily see that this puts the side of the tire to a greater test
than its surface ever gets in merely passing over the road. No tire will
withstand this rough treatment.
Chain Bruises. — Figure 250 shows a
tire that has been injured by the use of
chains. Almost any chain will injure
a tire if used to excess, but some are
more injurious than others. Evidently,
the chain used on this tire was fastened
to the spokes; at least, it appears that
it was held tightly in one place, as the
cutting appears at regular intervals.
The tread is cut through the fabric
and, in fact, loosened up and torn
badly in places. The least injury re-
sults from chains that are loosely ap-
plied and have play enough to work
themselves around the tire, distributing
the strain to all points alike. The
greatest amount of injury comes from
using the chains on hard paved streets,
where they are least needed.
Poor Alignment. — Figure 251 shows
a tire that is worn to the fabric. This
is a very common condition, and is
caused by the wheels being run out of
line and usually occurs on the front
wheels, affecting both tires alike,
although sometimes one tire only is
affected. Improper adjustment of the
steering apparatus, or a bent knuckle,
cross-rod or axle is responsible. Under
either of these conditions the tread will
wear away in a remarkably short
time.
It is to be assumed that all cars are received from the manufacturer
in perfect alignment, but after being run a while, the steering gear, if not
watched very closely, is apt to become affected by wear or accident. To
aid in steering, the front wheels are permitted to "toe in" just a little,
but if allowed to do so to any marked degree, this condition is bound to
result.
FIG. 251.— The
result of poor
wheel alignment.
FIG. 252.— Re-
sult of under-in-
flation.
OPERATION AND CARE 247
Under-inflation. — Figure 252 shows the result of running a tire under-
inflated, that is, too soft. In this condition, the tire is being constantly
kneaded by the road surface and the rubber is worked loose from its bond
to the fabric. The wavy condition of the tread is due to this loosening.
Another condition which is not visible in this figure is rim-cutting. There
are probably more tires injured from this cause than any other. Proper
inflation will prevent both conditions. There is a mistaken idea among
many motorists that it is easier on tires if they are not inflated quite to
the pressure recommended. Keep the pressures up to those recom-
mended. There is little danger of over-inflation unless an air bottle is
used. The prevailing pressure for tires is 20 Ib. times the diameter of
the tire. For example, the pressure for a 4-in. tire is 20 times 4, or 80 Ib.
Of course, the pressure should vary somewhat with the weight on each
tire, but if a car is properly tired the above figures will hold. In the
absence of any better test, a good rule to follow is to inflate to a sufficient
pressure to prevent the tires from showing any depression under the
weight of the car without passengers.
Blisters. — Small cuts in the rubber, especially if they extend to the
fabric, should be given immediate attention. If these cuts are neglected,
the tread will work loose from the fabric, sand will work in and form a
sand blister. Furthermore, water reaches the fabric and quickly rots it
so that a blow-out may soon result. As soon as discovered, such cuts
should be cleaned out and the cut filled with some plastic tire compound
made for this purpose.
173. Figuring Speeds. — In order to figure the speed of any automobile,
it is necessary to know three things, namely: the speed of the engine in
revolutions per minute, the gear ratio or gear reduction, and the size of
the rear wheels. To make this figuring unnecessary the chart of Fig.
253 has been produced, from which the result can be taken without any
actual figuring.
Thus, beginning at the bottom on the left hand side, the diameter of
the wheels is 37 in.; follow vertically up the 37-in. line until it intersects
the gear ratio diagonal. In this case the gear reduction is 3^ to I. The
37-in. line intersects this diagonal at the point C.
Then follow horizontally across to the right hand side of the chart,
where such a horizontal line would intersect the diagonals representing
the speed of the engine. In this instance the engine speed is taken at
2000 r.p.m., and the line intersects it at the point D. From this point
drop a vertical to the base, which will be intersected at a point represent-
ing the car speed, in this case 67 miles per hour.
The table can also be used to find the engine speed in revolutions per
minute, knowing the car speed in miles per hour (which can be read on the
speedometer}, the size of tires and the gear reduction. In such a case
26
248
THE GASOLINE AUTOMOBILE
proceed as before, obtaining the horizontal line C-D extending across the
diagram. Then starting on the right hand base line, at a point indicating
the speed as 67 miles per hour, draw a line vertically upward until it
intersects this C-D line. This point of intersection D will come on a
diagonal, giving the speed of the motor. In this case it comes on the
2000-r.p.m. line exactly, but if the speed were followed upward from 50
miles per hour, for instance, another point would be obtained not on any
of the curves drawn. However, it would be midway between 1600 and
1400, so that 1500 r.p.m. would be taken as the motor speed.
B.P.M. of Engine
32 34
Wheel diam. in inches
100 90 80 70 60 50 40 30 20 10 0
Oar speed. Miles per hour
FIG. 253.— Speed chart.
174. Interstate Regulations. — The lighting requirements of the
different states are practically uniform and call for two white lights in
front and one red light in the rear. It is usually required that the rear
license tag be illuminated with a white ray from the rear lamp. Many
cities now require that the headlights be dimmed. This makes it desir-
able to inquire regarding such regulations before driving through a
strange city.
All states with the exception of Louisiana require the registration or
licensing of automobiles in some form, but the law in Mississippi has
been declared unconstitutional. The registrations are renewable an-
nually except in the District of Columbia, Florida, South Carolina, Ten-
OPERATION AND CARE 249
nessee, Texas, and Utah, where they are perpetual, and in Minnesota,
where they are for 3 years. Professional chauffeurs must be examined
and licensed in nearly all states, while in some states even the owner and
the members of his family must have drivers' licenses.
Non-residents of a state are permitted to drive in most of the states
for limited periods without taking out a license, providing they have
complied with the laws of their own states and providing their own states
reciprocate in this respect. These periods vary from 10 days in New
Hampshire and Rhode Island to 90 days in California and Colorado and
to unlimited periods of some others.
In Oklahoma, South Carolina, Tennessee and Texas, non-residents
are not exempt from registration, but the fee is only from 50 cents to
$3 for these states. Oklahoma also permits its cities to license and
regulate the use of automobiles. In Connecticut, non-residents are
permitted to travel on their home licenses only provided they have two
license tags, one front and one rear. In Louisiana, the entire control is
left to the municipalities.
In Alaska, there is no license required except for dealers. In Porto
Rico, non-residents must secure a license from the Commissioner of
the Interior. The fee is $2 per month.
The motorist must remember that there are local restrictions every-
where, which could not be given in the limited space available here, even
if all of them were available. For instance, Wisconsin, Pennsylvania,
New York City, Detroit, Chicago, Province of Ontario, etc., either require
a full stop or slowing to 4 or 5 miles per hour in approaching a street car
stopping to let off or take on passengers. These and local traffic police
restrictions can be found out locally, or avoided entirely by driving slowly
and carefully at all times, and in a manner consistent with the rights of
others, particularly of pedestrians.
In case of accident, the motorist should always stop, obtain the names
of witnesses, and give his own name and other information freely, as well
as evidence a willingness to assist, whether in the wrong or not.
175. Canadian Regulations. — Upon entering the Dominion, the
owner or operator must give a bond for the re-exportation of the car.
This is to prevent cars being taken in permanently duty-free. In the
majority of provinces, a Dominion license and tags are necessary.
If the tourist is not known personally to the officer at the border, he
must take out the license and give the bond as mentioned above. But if
known, he may be allowed to enter free of both duty and tax for 7 days.
The bond given must be for twice the amount of duty, if the stay is
to be for less than 6 months. This is furnished by bonding companies in
the principal cities of the United States and Canada, and usually at the
border line, the usual fee being $5. The following are among those
250 THE GASOLINE AUTOMOBILE
who will furnish such a bond: Guarantee Co. of North America, 111
Broadway, New York City; J. A. Newport & Co., Niagara Falls, Ontario;
Niagara Falls Auto Transit Co., Niagara Falls, N. Y.; J. M. Duck,
Windsor, Ontario; A. J. Chester, Sarnia, Ontario. Messrs. Newport and
Duck will also procure the license and permit in advance, if requested,
the charge being $4.30.
176. Touring Helps — Route Books. — The whole of the United States
and the tourable parts of Canada are covered by the Automobile Blue
Books. Of these there are seven volumes, as follows: Vol. 1, New York
State and Lower Canada; Vol. 2, New England and the Maritime Prov-
inces of Canada; Vol. 3 ,New Jersey, Pennsylvania, Delaware, Maryland,
and Southeastern States; Vol. 4, The Middle West to the Mississippi
River; Vol. 5, The Far West from the Mississippi to the Pacific Coast;
Vol. 6, California, Oregon, Washington, British Columbia; Vol. 7, the
Metropolitan Guide. They are published by the Automobile Blue Book
Publishing Co., 2160 Broadway, New York, and 910 S. Mich. Ave.,
Chicago, at $2.50 a volume. There are also other good route books pub-
lished in different localities, among which is Kings Guide, which covers
the north central states in great detail. This is issued by Sidney J.
King, 626 S. Clark St., Chicago.
For its members, the American Automobile Association maintains a
route bureau and sells a number of excellent maps.
For those who can use them, the topographical maps of the United
States Geological Survey are most accurate and very interesting, giving
more detailed information than any of the others, particularly with regard
to difference of elevation. Information relative to them, prices, etc.,
may be obtained from the Director of the Survey, Washington. In
some states, county highway maps may be secured from the state high-
way department.
177. Cost Records. — It is always a good plan to know just what the
operation of an automobile costs. The following forms are suggested for
keeping data on which to base figures for the annual cost statement.
These forms can be ruled on the pages of any notebook of about 5 in. by
8 in. size. The notebook should be kept in the car so that complete
records can always be made. In preparing an annual statement of the
cost, it is customary to charge an annual depreciation of 20 per cent of
the original cost of the car. The total cost for the year should include
this depreciation charge, as well as the cost of gasoline, oil, tires, fines,
and repairs. Accessories are more properly chargeable against the
capital account of the car less an annual depreciation charge, the same as
the car itself. The cost record will also give the owner a reliable record
of the service obtained from his tires and the cost per mile.
OPERATION AND CARE
251
GASOLINE
Date
No. of
Gal.
Cost
Speedometer readings
Notes on carburetor
adjustment
-
Total ga
Miles
per gal., a
LUBRICATING OIL
Date
Gal.
Cost
Speedometer readings
Brand of Oil
Total ga
Miles pe
r gal., avj
\
252
THE GASOLINE AUTOMOBILE
Make-
TIRE RECORD
Serial No. Size-
Date on
Date off
Speedometer Reading
Front or Rear
On
Off
TIRE REPAIRS
Date
Nature
Cost
Remarks
First Cost-
Repairs —
Total Cost-
SUMMARY
Total Mileage-
Cost per Mile-
NOTE: Keep a separate sheet for each casing and tube.
OPERATION AND CARE
253
REPAIRS
Date
Name
Cost
Remarks
Part
Labor
Total cost
ACCESSORIES
Date
Name and Make
Cost
Remarks
FINES
Date
Place
Amount
Remarks
INDEX
Air cooling, 122
Alcohol AS * fuel, TS
heating value, 79
xise in rs<iistor, 124
Alignment of wheels, 246
Alternating current, 127
Ampere, definition of, 127
Armature of magneto, 156
At water Kent ignition, 141
Automatic spark advance, 151
Atwater Kent, 143
Ddeo, 151
Eisemann, 163
Westinghouse, 146
Axles, dead, 12
front . 8
live, 13, 71
rear, 12, 71
B
Batteries, dry, 128
storage, 128, 182, 224
Battery charging, 185
connections, 129
ignition, 130
troubles, 224
Bearing troubles, 221
Bevel gear drive, 71
Bloc cylinder castings, 55
Blow-outs, tire, 244
Bodies, types of, 2
Bosch magneto, 167
dual system, 170
two-independent system, 173
Brakes, 16
troubles, 230
use of, 233
Buick oil pump, 108
rear axle, 73
Burton process, 76
Cadillac cooling system, 121
"wght ," engine, 60
"four" engine, M
oiling system, 111
Calcium chloride, 124
Cam angles, SO
shafts, 58
Canadian regulations, 249
Carburetor adjustments, us
principles, 79
troubles, 221
Carburetors, Carter, 97
Holley, 86, 87
Kingston, 90
Marvel, 91
Kay field, 95
Schobler, 82, 84
Stewart, 89
Stromberg, 94
Zenith, 94
Cars, electric, 1
gasoline, 2
steam, 1
types of, 2
Cells (see "Batteries")
Change gears, 66
Charging batteries, 185
Chassis, the, 2
Ford, 48
Hollier "eight," 47
Mitchell "eight," 46
Studobaker "six," 5, 45
truck, 12
Clearance and compression, 39
Clutches, 64, 228
Clutch troubles, 228
Coils, vibrating, 132
non-vibrating, 137, 156
Cold test for oils, 104
Commercial cars, 4
Compression, 39, 216
255
256
INDEX
Condensers, 132, 225
Connecticut ignition system, 139
magneto, 160
Carbon deposits, 220
Control systems, 23
Cooling the cylinders, 40, 117
solutions, 123
troubles, 227
Cost records, 250
Cranking, 231
Crank shafts, 57
Current, direct and alternating, 127
Cycles, 25
four-stroke, 26
two-stroke, 35
Cylinder cooling, 40, 117
oils, 104
Delco ignition, 147
starter, 190
Depreciation, 250
Differential gear, 13
Direct current, 127
Disc clutch, 65
Displacement, piston, 39
Distributor system, 137
Dixie magneto, 166
Drive, final, 70
-shaft, 69
Driving, 232, 234
in city, 235
Dry battery, 128
troubles, 224
Dual ignition, 160
E
Eclipse Bendix drive, 197, 203
Eisemann magneto, 161
Electrical definitions, 127
Electric cars, 1
ignition, 39, 127, 153
starters, 181
Electrolyte, 184
En bloc cylinders, 55
Engine, 25
Buda, 52
Cadillac, 51, 60
Ford, 53
Franklin, 56
Engine, Jeffrey, 54
tfnight, 33
Mitchell, 55, 63
Packard, 63
Speedwell, 34
Studebaker, 52
troubles, 214, 216
Wisconsin, 50
Engines, eight cylinder, 60
four cylinder, 50
four-stroke, 26
horse power of, 41
six cylinder, 56
twelve cylinder, 63
two-stroke, 35
Feed systems, gasoline, 99
Fire test for oils, 104
Firing order, four cylinder, 57
eight cylinder, 62
six cylinder, 58
Flash point of oils, 104
Flywheels, 38
Force feed oiling, 111
Ford chassis, 48
control, 23
cooling system, 119
engine, 53
lubrication, 106
magneto, 174
rear axle, 72
timer, 135
transmission, 69
Four-stroke engine, 26
Frames, 6
Franklin, cooling, 122
engine, 56
frame, 6
Friction, 103
Fuels, 75
Gasoline, 77
heating value of, 79
mixtures, 79
records, 251
Gear sets, sliding, 66
location of, 44
planetary, 67
Glycerine for cooling, 124
INDEX
257
Gravity feed system, 99
Gray and Davis starter, 193
Grinding valves, 217
H
Holley carburetors, 86, 87
Hollier "eight" chassis, 47
Horse power formulas, 41
Hydrometer, battery, 184
Baume", 77
Ignition, 39
systems, 127, 153
troubles, 223
Inductor magneto, 163
Jesco starter, 205
Mitchell "eight" chassis, 46
engine, 63
"six" engine, 56
Mixtures, fuel, 79
Mixture troubles, 222
Motors (see "Engines")
starting (see "Starters")
Mufflers, 40
O
Ohm, definition of, 127
Oiling (see "Lubrication")
Oil pumps, 106
records, 251
Oils, cylinder, 104
Overhauling the car, 238
Overland oiling, 109
cooling, 118
valve adjustment, 218
Kerosene, 78
heating value of, 79
Kingston carburetor, 90
Knight car, Lyons, 49
engine, 34
oiling, 113
K-W magneto, 163
master vibrator, 137
M
Magneto, Bosch, 167
Connecticut, 160
definitions, 177
Dixie, 166
Eisemann, 161
Ford, 174
K-W, 163
Remy, 157
troubles, 225
Magnetos, principles of, 155
high and low tension, 156
Magnets, 153
Manifolds, intake, 102
Marvel carburetor, 91
Master vibrators, 136
Mechanism of engines, 28
28
Packard engine, 63
Parallel battery connections, 129
Petroleum, 75
Pfanstiehl coils, 133
master vibrator, 137
Piston displacement, 39
Planetary gear set, 66
Plugs, spark, 135
Power diagrams, 43
Power, horse, 41
plant and transmission, 14, 43
troubles, 214
plants, 50
Pressure feed systems, 100
Pressures, for tires, 247
R
Rayfield carburetor, 95
Rear axles, 12, 71
Records, cost, 250
Regulations, interstate, 248
Canadian, 249
Remy battery ignition, 149
magneto, 157
Repair records, 253
Rims, 20
Rittmann process, 76
258
Rotary valves, 34
Route books, 250
INDEX
S
Schebler carburetors, 82, 84
Series battery connections, 129
Shafts, cam, 58
crank, 57
drive, 69
propeller, 69
Silent Knight engine, 34
Skidding, 236, 245
Spark advance, 151
Atwater Kent, 143
Delco, 151
Eisemann, 162
Westinghouse, 146
plugs, 135
Speedometer drives, 21
Speeds, figuring, 247
Splash oiling system, 106
Springs, 6
care of, 230
Starters, 180
Delco, 190
electric, 181
Gray and Davis, 193
Jesco, 205
U. S. L., 204
Wagner, 197
Ward-Leonard, 187
Westinghouse, 199, 200
Starting in cold weather, 222
generator troubles, 209
motor troubles, 208
on spark, 179
system, care of, 207
Steam cars, 1
Steering gear, 10
Stewart carburetor, 89
vacuum feed system, 100
•Storage batteries, 128, 181
battery, care of, 209
in winter, 209
troubles, 209, 224
Stromberg carburetor, 94
Strut rods, 16
Studebaker chassis, 5, 45
cooling, 119
engine, 55
gear set, 68
Studebaker ignition, 149
oiling, 119
starter, 199
Thermo-syphon cooling, 118
Three point motor support, 44
Time of spark, 151
Timers, 135
Timing, magneto, 176
Tires, 19, 240
pressures for, 247
records, 252
troubles, 243
Torque arm, 15
tube, 16
Torsion rods, 16
Transmission gears, 66
location of, 44
planetary, 66
troubles, 228
Troubles, 213
Trucks, 4
Two-stroke engines, 35
U
Unisparker, 142
Universal joints, 15, 69
U. S. L. starter, 204
Valves, 30
adjustment of, 217
arrangements of, 32
grinding, 217
rotary, 34
timing, 29, 219
Vaporization, principles of, 76
Viscosity of oils, 104
Volt, definition of, 127
Voltage of dry cell, 128
of spark, 132
of storage cell, 129
W
Wagner rectifier, 186
starter, 197
Ward-Leonard starter, 187
INDEX 259
Washing the car, 240 Wisconsin engines, 50
Water cooling systems, 117 oiling system, 112
Westinghouse ignition system, 144 Worm drive, 71
starters, 199, 200 steering gear, 10
Wheel alignment, 229, 246
Wheels, 18
Winter cooling solutions, 123 Zenith carburetor, 94
THE LIBRARY
UNIVERSITY OF CALIFORNIA
Santa Barbara
THIS BOOK IS DUE ON THE LAST DATE
STAMPED BELOW.
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