1935 Cadillac - GM Heritage Center

129
GASOLINE SYSTEM
during the warming-up period. As the engine
becomes warm, the tension of the thermostat
gradually lessens and the inrushing air becomes
the dominant force, thus moving the choke valve
to the wide open position for normal operating
temperatures.
INTAKE
SILENCER
An intake silencer is used on all models. The
silencer silences the intake noises at all engine
speeds under various throttle openings. There are
no moving parts or baffle plates on these silencers.
A feature of the air silencer is the copper gauge
air cleaner which is designed to catch any dust or
lint in the air before it is drawn into the carburetor.
It is automatic in operation and requires no attention
other than periodic cleaning and oiling.
The intake silencers on the Cadillac cars are
connected to the radiator in such a way as to
secure fresh, cool air through a passage between
the radiator core and casing instead of using the
warm air from under the hood. This arrangement
permits the use of higher compression and greater
spark advance and results in increased power and
engine performance.
Fig. 9. Diagram showing fuel distribution in LaSalle
engine. Each carburetor barrel supplies fuel to four
engine cylinders
diaphragm down against the pressure of the diaphragm
spring, and keeps it in this position until
more fuel is needed in the carburetor and the
needle valve open.
The rocker arm in the Cadillac pump is in two
pieces, operating together when the diaphragm is
working up and down. When fuel is not required
and the link or lower part of the operating lever
is held down at one end by the diaphragm pullrod,
the upper part operates in the usual way.
This is made possible by the fact that the lever
operates against the link only in the downward
direction, the upward movement of both parts
being accomplished by spring pressure. A second
spring is provided for keeping the lever in contact
with the driving rod at all times.
FUEL
PUMP
The fuel feed on all cars is by a fuel pump. This
pump on the Cadillac models is operated by a
push (driving) rod riding against a cam on the
distributor shaft and is located at the front of the
engine on the left, in the coolest position under
the hood. The fuel pump on the LaSalle, which
is combined into a single unit with the vacuum
pump for operating the windshield wiper, is operated
by the camshaft. It is located at the front
of the engine on the right side.
GASOLINE TANK FILLER
The gasoline tank filler on the Cadillac Series
10 and 20 cars is located in the left-hand side at
the rear of the body. On all other Cadillac models
and the LaSalle the filler is located on the top of
the left rear fender.
The principal moving element of the fuel pump
is a diaphragm actuated through a series of levers
and rods. When the diaphragm assembly is
pulled down, it creates a vacuum in the pump
chamber which allows the atmospheric pressure
in the rear tank to force gasoline into the sediment
bowl and through the strainer and inlet valve into
the pump chamber.
The diaphragm is moved upward on the return
stroke by pressure of the diaphragm spring. On
this stroke the gasoline is forced from the pump
chamber through the outlet valve, into the vapor
dome and thence to the carburetor.
When the carburetor bowl is filled and the inlet
needle valve closes, a back pressure is created in
the fuel pump chamber. This pressure holds the
Fig. 10. View showing arrangement of gasoline tank
filler on Series 30, 40, 60 and LaSalle cars. The rear
fender is removed in this illustration. The filler on the
Series 10 and 20 cars is at the rear of the body.