Hudson 1938 Terraplane, Owner'S Manual

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46 H U D S O N T E R R A P L A N E
C A R B U R E T O R A N D F U E L S Y S T E M
Carburetor—De luxe Models
The carburetor on De luxe models is
of the single manual choke type, em-
ploying a vacuum-controlled metering
p i n f e a t u r e w h i c h p r o v i d e s h i g h
efficiency and economy of operation.
The position of the metering pin, being
controlled by engine vacuum, provides a
rich mixture at cranking speed when
vacuum is low, obviating the neces-
sity of excessive choking. This feature
likewise prevents the use of more than
the required amount of fuel when the
operator presses the accelerator to open
the throttle.
Manifold Heat Control
The manifold heat control valve (A),
Figure 39, is adjustable for winter and
summer driving. The winter setting is
indicated by the letter "W" on the ex-
haust manifold above the valve. For
summer driving, except in areas where extreme heat conditions are experienced,
the pointer on the valve should be directed straight upward. For extremely hot
areas the pointer should be set to letter "S" or to the front of the engine.
The control valve is adjusted by loosening nuts (B) sufficiently to relieve
pressure of bar (C). Be sure to tighten nuts securely after valve is moved to prevent
exhaust leaks developing.
Carburetor—Super Models
The carburetor, Figure 40, on your Hudson Terraplane Super car is of the
down-draft Duplex type, incorporating Climatic Control (self-controlled choke),
accelerating pump and automatic heat control.
Two metering pins are provided, each of which proportions the fuel mixture
for its respective carburetor barrel. One barrel supplies the four center cylinders
and the other barrel supplies the two cylinders at each end of the motor. By this
feature improved fuel distribution is obtained, resulting in increased efficiency.
Carburetor Choke
The automatic choke mechanism provides a cam (D), which, when the acceler-
ator is depressed before starting the engine, swings into place and holds the
throttle open the correct amount for starting. As soon as the accelerator is again
depressed after starting the engine, this cam is pulled out of place and the throttle
drops down to the "fast idle" position, which gives enough motor speed to
prevent stalling during the warm-up period.