1928 Cadillac - GM Heritage Center

10 CADILLAC OPERATORS MANUAL
OPERATION 11
Gasoline Gauge
The gasoline gauge is the lower dial, marked "Fuel," in the center of the
instrument board. It indicates in gallons the quantity of fuel in the tank
at the rear of the car, and is op-
1 ^ : - ^
erated electrically. To read from the
gauge the quantity of fuel in the
tank, the ignition must be switched
on. When the ignition is switched
off, the gauge does not indicate the
amount of fuel in the tank.
As filling station rules forbid
running the engine while the gasoline
tank is being filled, the ignition
should be snitched off until the
Figure 2. The gasoline gauge is operated engine stops and then switched on
electrically by current from the ignition circuit.
again and left on while the tank is
being filled.
If the fuel supply should give out on the road, so that the vacuum tankon
the dash becomes empty, it. will be necessary after refilling the gasoline
tank to prime the vacuum tank. To do this, close the throttle and hold
the starter down for 20 to 30 seconds. The throttle must be closed while
this is done.
Temperature Indicator
The gauge at the extreme right of the instrument panel (Fig. 3) is a
thermometer for indicating the temperature of the engine and takes the
place of a temperature indicator on the
radiator. The bulb end of the thermometer
is inserted in the water-jacket at the rear
end of the right-hand cylinder head, and is
connected by a small tube to the dial on the
instrument board.
The normal engine temperature after the
engine becomes warm is 150 to ISO .
Throttle Control
Fipir- 3. The temperature of
the water in the cylinders should
rar.ge from 150° to 180'.
The power and speed of the engine are controlled by opening and closing
a throttle valve in the carburetor. This throttle is operated both by a hand
lever and a foot pedal.
The foot pedal, or accelerator, is at the right of the brake pedal (Fig. 1).
The hand control is the upper lever above the steering wheel. Both controls
operate the same throttle; the hand lever, however, remains in the position
to which it is moved, whereas the accelerator must be held down to keep
the throttle open.
The normal position of the throttle hand lever for driving the car is all
the way up (at "Close"). In this position the throttle of the carburetor
is open just enough to permit the engine to run at idling speed after it is
warm. For starting, however, the lever should be moved approximately
one-fourth the way down, and should be left in this position until the engine
is warm enough to permit the lever to be returned to the idling position
without stalling the engine.
In cold weather, the accelerator should not be pushed down suddenly
before the engine is warm. Sudden opening of the throttle before the engine
is warm causes "popping-back" in the carburetor. This should be avoided
as much as possible by judicious opening of the throttle during the warmingup
period. (See page 45 under "Use of Accelerator Before Engine Is Warm.")
Spark Control Lever
Correct timing of the ignition in relation to the positions of the pistons
is accomplished automatically by the timer-distributor, which provides for
all ordinary advancing and retarding of the spark. (See page 87 under
"Timer-Distributor.") A hand control is also provided for retarding the
spark on certain occasions as hereafter described.
The hand control is the right-hand of the two levers on the instrument
board directly in front of the steering column (Fig. 1). For average driving,
the correct position of this lever is all the way toward "Advance."
The lever should be left in this position except on the following occasions:
1. If the engine is being cranked by hand, the spark should be fully
retarded by moving the lever all the way toward "Retard."
2. In pulling at low speeds with the throttle well open, the spark should
be retarded.
3- If, because of the accumulation of carbon in the combustion chambers,
the engine knocks or "pings" on acceleration, the spark may be retarded
slightly. As soon as possible, the carbon should be removed so that the
spark can be fully advanced.
Carburetor Enriching Button
The button at the lower left of the instrument board (Fig. 4) controls a
device on the carburetor for temporarily enriching the fuel mixture supplied
to the engine. When starting the engine, it is necessary to have the proportion
of liquid gasoline in the fuel mixture greater than at other times,
because in a cold mixture only a part of the gasoline is vaporized. Pulling
out the enriching button increases the proportion of liquid gasoline to air,