ENGINE
A. FLOW OF COOLING WAT E R
(1) Water Return Pipe
(2) Thermostat
(3) Cylinder Head Water Jacket
(4) Cylinder Block Water Jacket
(5) Radiator
(6) Cooling Fan
(7) Water Pump
The cooling system consists of a radiator (5), a centrifual water pump (7), a fan (6) and a thermostat (2). The
water is cooled as it flows through the radiator core, and the fan behind the radiator pulls the cooling air
through the radiator core. The water pump receives water from the radiator or from the cylinder head and
forces it into cylinder block. The thermostat open or closes according to the water temperature. When the
water temperature is high, the thermostat opens to allow the water to flow from the cylinder block to the
r a d i a t o r. When the water temperature is low, the themostat closes and the flow stays within the block. The
opening temperature of the thermostat is approx. 70
o
C( 1 6 0
o
F) .
B. WATER PUMP
The water pump is driven with the fan drive pulley,
which is on the water pump shaft and driven by the
crankshaft with a belt. The water pump sucks the
cooled water, forces into the cylinder block and
draws out the hot water to the radiator repeatedly.
The mechanical seal (3) prevents the water from
entering the bearing (1).
(a) From the Thermostat
(b) To the Cylinder Block
(c) From the Radiator
(1) Bearing
(3) Mechanical Seal
(2) Pump Body
(4) Pump Impeller
2.3 COOLING SYSTEM
