Page 135 - Vauxhall 20-60 H.P. (R Type) Chassis Shop Manual

VAUXHALL 20-60 SHOP MANUAL

ADJUSTMENT OF INDUCTION

MANIFOLD HEATING VALVES

SECTION The adjustment of induction manifold heating valves greatly assists
582 carburation, and on all cars the adjustment of the valves should be re-set

for summer and winter conditions. The following is an approximate setting
for the valves:—
For winter conditions: – ( From November to April inclusive ) approximately
three turns open.
For summer conditions: — ( From May to October inclusive ) approximately
one turn open.

It is necessary to use discretion in the adjustment of these valves for
summer conditions as excessive pinking and lack of power will result if they
are opened too much during warm weather.

HOBSON K-S TELEGAGE

( See Figure 40 )

SECTION Description: —The Telegage consists of three units the head, tank unit
583 and air line. In operating condition, the air tube and top bell of the tank
unit, and air line connecting the tank unit to the head are filled with air
( ‘C’ and ‘D’. ) The petrol tries to rise to the same level in the tank unit as
it is in the tank. This is not possible because of the air trapped between the
bottom of the tank unit and the liquid in the head. However, the efforts of
the petrol to get into the top bell presses on the trapped air.

This pressure is communicated through the air tube and air line to the head
on the instrument board where it is recorded by the rise of the red liquid in
the glass tube. The tank unit ( ‘A’ ) shows the air tube and top bell, which
must always be filled with air. The petrol tries to enter through holes ‘B’
and( ‘C’ ) and this presses on the trapped air. This is the only part of the tank
unit that has anything to do with the reading of the gauge. The vent tube,
open at the top, is merely a safety device, which protects the gauge against
high pressure. It does not enter into the operation of the gauge in any way.
The remainder of the tank unit, that is, the air cup, air dome, air delivery
tube and bottom bell act only as a means of supplying fresh air to the top
bell. This is to overcome the loss of air due to a sudden drop in temperature.

The air supply mentioned above is obtained by utilizing the movement and
slop of petrol in the tank. Whenever the petrol is below the level of the
air cup, the air cup and air dome are of course filled with air. As the petrol
surges and slops into the air cup it traps the air in the air dome and drives
it down the air delivery tube. At the bottom of the tube the air bubbles out
and rises under the bell. It enters the top bell through the hole ( ‘C’ ) and
replaces any petrol which may be there. When the top bell is full of air these
bubbles pass off through hole ( ‘B’ ) and are not used.
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