Cadillac
To install, reverse the operations under "Removal."
In installing, care should be taken to see that the surface which
comes in contact with the intake header is smooth and free from
dirt.
Carburetor Thermostats
Throttle pump and vent control thermostats: When the accelerator
pedal is pushed down quickly the plunger of the throttle pump
forces compressed air into the carburetor bowl above the gasoline,
momentarily forcing additional gasoline through the spraying
nozzle.
As good acceleration is obtained with a somewhat leaner mixture
after the carburetor has become warm, a thermostat is provided
to open a vent hole when the temperature of the carburetor reaches
a predetermined point, thus providing a release for a portion of
the air compressed by the pump. The result is that less gasoline
is forced through the spraying nozzle.
A second thermostat is also provided, the purpose of which is to
open a large vent from the carburetor bowl during hot weather,
this being desirable when very high test gasoline is used.
The vent control thermostat does not open until a much higher temperature
is reached than that at which the throttle pump control thermostat
operates.
Both thermostats are attached to the same block, the throttle pump
thermostat being the inner one and the vent-control thermostat
the outer one.
Both thermostats are properly adjusted when the carburetor is assembled
at the factory and re-quire no further attention unless tampered
with.
If tampered with, thermostats may be readjusted in the following
manner:
Adjustment of throttle-pump control thermostat: Remove the thermostat
with block from the carburetor body, being careful not to injure
the gasket. This may be done after removing the left-hand screw
in the face of the thermostat block.
The thermostat adjustment is made by turning the screw (E) (Fig.
4) which should be so adjusted that the vent hole is just closed
at a temperature of 74 degrees F. and just open at a temperature
of 78 degrees F.
To test this, provide two dishes of water, one at a temperature
of 74 degrees F. and the other at a temperature of 78 degrees F.
First immerse the thermostat with block in the water at 74 degrees.
A hen removed, the vent hole should just be closed. If it is not,
readjust the screw (E) controlling the thermostat.
Then immerse it in the water at 78 degrees. The vent hole should
then be opened. If it is not, re-adjust the screw.
When the vent hole is just closed at a temperature of 74 degrees
and just open at a temperature of 78 degrees, the adjustment is
correct and should be locked by tightening the lock nut.
Adjustment of vent control thermostat: The vent control thermostat
should he adjusted in exactly the same manner as the throttle pump
control thermostat, but to different temperatures.
The vent control thermostat should be so adjusted that the vent
hole is closed at a temperature of 125 degrees F. and open at a
temperature of 130 degrees F.
If very high test gasoline is used (luring extremely hot summer
weather it may be found desirable to change this setting to have
the vent closed at 115 degrees F. and open at 120 degrees F.
In making these adjustments, care must be exercised to make certain
that the water used is exactly at the temperature given. This work
must be done carefully and should be entrusted only to a careful
workman.
The efficient operation of the carburetor depends considerably
upon the skill used in making these adjustments.
If the gasket between the block and the carburetor is damaged in
removal, replace it with a new one.
There should he no possible chance for a leak around the vent passages.
Previous page 1927
Supplement Home Next page 
|