New-York tribune., 1922-11-19
Mastering of Details of Pow
err Which Drives Machine
VIII Add a Great Deal
TO Pleasures of Motoring
Mechanism Is Described
Process of Consuming Fuel
and Effect ON All Parts of
Car Shows Need of Care
BY Fl. Clifford Brokaw
Technical Director, West Side Y. M.
C.. A. Automobile School


It has an engine which is Of great i'm
pcrtance TO the cars efficiency. One of
the last things many motorists learn is
the general principles by which an en-
gine operates, although this is funda-
rnental knowledge that every owner
ought TO possess.
When the driver of car lifts up the
hood and gazes at the mechanical de-
vices before his eyes they appear to be
tremendous mystery. It appears to
AS matter OF fact 1t is not difficult to
become familiar and even friendly with
an automobile engine. To do this ought
TO be in the program of every car
owner, and the quicker he gets to it
the greater will be his enjoyment in
motoring.
The automobile engine is known as
an internal combustion engine; that is,
the fuel which gives the power is
burned in the engine itself. The fuel
used In the auto engine Is gasoline.
This fluid is put into tank from which
it either flows By gravity or IL forced
by air pressure to the carburetor or is
drawn into a small auxiliary tank by
suction, from which it flows by gravity
to the carburetor.
In order to secure a rapid burning OF
this fuel it ia necessary to mix it with
a large quantity Of oxygen, whicn is
most readily secured from the air. The
carburetor measures out small guam
tity OF gasoline, just the right amount
TO charge each cylinder each time, and |
mixes it with the right amount of air
to supply the desired amount of oxygen. |
During this mixing process the gasoline |
is changed from liquid to vapor, so |
that the fuel which goes into the engine |
is in the form of gas.
Arrangement of Piston
The simple engine of one cylinder is |
arranged SO that piston may move up
ard down throughout its length and at
the same time keep an air-tight con-
tact with the sides of the cylinder
This piston is connected with crank
shaft through a connecting rod so that
the reciprocating, or up and down mo-
ton, OF the piston is transformed into
rotary motion In the crank shaft, This
rotary motion is maintained throughout
all tho gearing and other driving mech
Rnism of the car to and including the
rear wheels.
The cylinder OF the engine is
equipped with two valves, one for ad-
mitting the charge of gas and the other
for permitting the burned or used gas
to escape. These are called the inlet
cylinder Is this-with the piston all
the way UP in the cylinder there is
only small space in which the gas
can be contained at the top Of the
cylinder. When the crank shaft is ro-
tated the piston will travel down the
cylinder, greatly enlarging the space at
the top. When this upper space is
thus enlarged q vacuum is created. A
vacuum causes suction.
The inlet valve is open at this time
and this suction Is communicated to
the carburetor by means of an inlet
pipe. A charge Of the mixture of gaso-
line and air is drawn in by the suction
which entirely fils the upper part Of
the cylinder. The inlet valve is then
closed and as the crank shaft continues
TO rotate the piston ID forced back to
the top of the cylinder, COMPRISING the
entire cylinderful 0f gas into the small
space at the top. spark then occurs
which ignites the gas and causes it to
explode or burn very rapidly.
AS this gas burns the temperature
rises greatly, causing the pressure to
increase in the same proportion. This
1 pressure forces the piston down TO the
4 lower end of the cylinder, turning the
q crank shaft and developing the power
that is impaired to the rear wheels and
makes it possible for the auto to go
ahead or back up.
lower end Of the cylinder the exhaust
valve opens and as the crank shaft
continues to rotate the piston moves
back to the top of the cylinder, clean
ing the burned gas out of it in the
process. This UP and down movement
Of the piston is repeated by the engine,
and consequently the car moves.
Process Stops Noise
The burned gas as it goes out of the
cylinder is still under considerable
pressure and if 1t were exhausted di-
rectly into the air would make loud
report. Therefore it is conducted by
suitable pipe to the muller, where
is is allowed to cool and is broken up
into streams so that it makes very
little noise when reaching the air.
It will be observed that in simple
engine OF only one cylinder power is
applied only one-fourth of the time.
And during that time Its force varies
greatly. Consequently, q minimum of
four cylinders is usually used in an
automobile engine to give more
steady application of power, and often
six, eight and twelve cylinder engines
are found in cars TO provide an even
zteadier application of power.
1t is necessary TO have q cooling
system, either air or water. which
will keep the engine from becoming
ovcrheated, Otherwise the explosion
IN the chamber would occur too soon to
be most effective. II is essential that
the cylinder be fabricated. The oil
should have sufficient body to mais~
tain positive film between the piston
and the cylinder walls and yet it must
not be too heavy or it will consume
q great deal OF the power generated.
Ii should have high-power test
that is it should not decompose rap
idly by heat. The cooling system also
helps keep the oil from becoming toe
hot
Having absorbed these facts about
the engine fhs owner can supplement
them by reading carefully the instruc-
zion book furnished by the manufac-
turcr of his machine. Perhaps he may
want to GO still further into the stady
Of the motor by reading one Of the
several good books on the subject or
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