Figure 1-11. Circulation of coolant in engine water jacket.

c. Temperature Sensing Unit The temperature

1-16.

Engine Temperature Gage

sensing unit is mounted in direct contact with the engine

coolant and is usually located at the rear of the engine.

a. General. The engine temperature gage provides

1-17.

Water Distribution Tube

a convenient means for checking engine-operating

temperatures.

There are two principal parts in the

a. General. Some engines, particularly L-head

assembly, the gage unit and the temperature sensing unit.

types, have a water distribution tube in the water jacket

b. Gage Unit The gage unit mounted on the

extending from the water pump to rear end of engine.

instrument panel and connected to the temperature

This long, flat, thin-walled tube has an opening at one end

sensing unit registers the temperature of coolant

facing the pump outlet and a number of outlet openings

surrounding the engine unit.

along one side facing the water passages around the

exhaust valves.

b. Function (fig 1-13) The water distribution tube

receives coolant from the pump and delivers it through

spaced outlet openings directly to the hottest parts of the

engine, such as the exhaust valve seats. The tube is

removable, but the water pump must first be taken off

before the tube can be reached In order to draw the tube

completely out of the water jacket, the radiator must also

be taken out.

Figure 1-12. Engine temperature gage.

1-9