jacketed full length to prevent distortion of the cylinder walls. The cylinder head gasket has large water holes through
which the water flows past the valve seats and carries heat away from the valves, providing positive cooling of valves and
valve seats. The waterflow around the combustion chambers, cylinders, and valve seats prevents the formation of hot
spots and steam pockets. The hot water is directed to the radiator where it is cooled by the slipstream of air from the
ventilator fan. This engine does not have a thermostat regulating the water temperature. To prevent overcooling of the
engine and the formation of sludge, always cover the radiator when operating in freezing temperatures. Use canvas, cloth,
or cardboard to cover the front bottom part of the radiator. The covering will reduce the cooling surface of the radiator and
raise the operating temperature of the engine. Refer to table VII for the amount of surface to be covered at various
temperatures. After the radiator has been covered, run the engine for 10 minutes and observe readings on the water
temperature gage. If the water temperature rises above 180F., reduce the amount of the covered area. If the water
temperature remains below 160F., increase the amount of the covered area. The proper operating temperature of the
engine is 160 to 180F.
184. Water Pump Assembly (fig. 96)
a. Removal. Refer to paragraph 130b.
b. Disassembly.
(1) Remove the four screws and lockwashers attaching the fan to the water pump pulley (1) and remove the
fan.
Table VII. Radiator Surface Covering Chart.
Temp. F.
Temp. F.
Surface to
Surface to
be covered
be covered
+25 --------------------------
1/4
0 ------------------------------------
1/2
+20 --------------------------
1/4
-10 ---------------------------------
3/4
+10 --------------------------
3/8
-20 an below---------------------
7/8
(2) Remove the pulley (1) from the water pump shaft (9).
(3) Remove the cover screws (13) attaching the cover (12) to the water pump body (4). Tap the cover (12)
lightly with a plastic hammer and remove it from the body.
(4) Remove and discard the gasket (11).
(5) Pull the impeller (10) off the shaft (9).
(6) Use an arbor press and press the shaft (9) and bearing (8) assembly from the body (4). Be careful not to
damage the water pump body when pressing out the shaft and bearing. Make sure that the water pump body
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