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1.5L REVOTORQ ENGINE
74
COMPONENTS
A. Radiator
The radiator is a heat exchanger that is used to
dissipate the coolant heat. A radiator fan is used to
create forced air circulation.
Radiator consists of radiator core, inlet tank and an
outlet tank.
Cores are usually made of aluminum. The core has
two sets of passages, a set of tubes and a set of
fins attached to the tubes. The tubes run from inlet
tank to outlet tank. Coolant flows through the tubes
and air flows between the fins. The atmospheric air
passing between the fins carries away the heat,
which lowers the temperature of the coolant.
B. No Loss Tank
As the engine cools down the system pressure falls
down and vacuum is formed. The vacuum valve in
radiator cap opens and allows the water from the
No Loss tank to return into the radiator. Thus the
system does not have any coolant loss during
normal operation.
C. Thermostat
The thermostat controls the flow of coolant as
follows.
1. During a cold start, thermostat does not allow
coolant to flow to radiator since it is closed;
instead the coolant flows through bypass outlet
back to the engine .Thus short circuiting of
radiator which helps in attaining engine working
temperature in a very short period.
2. As soon as the coolant temperature reaches the
opening temperature of the thermostat, the
thermostat valve starts opening gradually and
coolant starts flowing to the radiator. At the
same time the thermostat by-pass starts closing
gradually.
3. As the engine working temperature reaches
thermostat full open temperature, the thermostat
valve opens fully. In this condition maximum
quantity of engine coolant flows from radiator to
water pump.
Testing Parameters
Thermostat start open temperature is 86º to
90ºC at 0.1mm travel.
Full open travel of 8 mm (Min.) at temperature
is 100º C
Leakage through main valve at room
temperature and 0.3 kg/cm
2
is 1500cc/min
MAX.