
102 LIGHT AND HEAVY VEHICLE TECHNOLOGY
System hot
System cold
V\
Fan or
impeller
Variable
throttle
valve
posit ion
Figure 5.4 Air-cooling fan and throttle value
valve, so that adequate movement is transmitted to the
ring within the available working stroke of the unit.
The thermostat is generally installed in the hot air duct
leading from the lower part of the plenum chamber
(Figure 5.5).
5.3 ENGINE WATER-COOLING SYSTEM
Circulation of cooling water
A very simple form of engine water-cooling system,
known as natural or thermosyphonic circulation (Figure
5.6), was used in many early motor vehicles up to the
late 1930s and provides a useful introductio ...