FUEL SYSTEM. - TM-10-3930-622-140027

d. Oil filter. A replaceable-element oil filter is

pulley. The water pump draws coolant from the radiator

mounted on the right-hand side of the crankcase. The

and pumps it into water jackets which extend the full

oil filter is of the by-pass type, a constant flow of

length of the cylinders.

pressure oil being directed to and from the oil filter body

d. Water outlet pipe, thermostat and by-pass line.

assembly through flexible inlet and outlet hoses.

The water outlet pipe is mounted on the rear end of the

1-9.

FUEL SYSTEM.

cylinder head. A bellows-type thermostat internally

mounted in the water outlet pipe contains a restriction

a. The fuel system consists of an air cleaner, fuel

valve which prevents free return of the coolant to the

tank, fuel pump, governor and carburetor, together with

radiator upper area at temperatures below 177 deg F.

control linkages, interconnecting lines and fittings.

With the thermostat valve closed, coolant is returned

directly to the water pump inlet through a bypass line.

b. Air cleaner assembly. An oil-bath type air

This bypass line enables the coolant to circulate through

cleaner is mounted above the left-hand side of the

the engine assembly until the coolant temperature

engine on the engine cowl. The air cleaner provides

exceeds 177 deg F. The thermostat valve starts to open

filtered air for the carburetor assembly.

at this temperature and is fully open at 182 deg F.

c. Fuel tank assembly. A 10.4 gallon, welded steel

permitting free circulation of the coolant to the radiator.

tank, provided with a tank unit float assembly and shut-

e. Fan assembly. A fan assembly and pulley

off cock is mounted on the right side of the truck frame.

adapter are attached to the water pump pulley. With the

The fuel tank is connected with tubing directly to the fuel

engine in operation, the fan assembly pushes cooling air

pump.

through the radiator core.

d. Fuel pump assembly. A diaphragm-type fuel

1-11.

IGNITION SYSTEM.

pump is mounted on the left side of the engine assembly

and is actuated by a rocker arm that contacts an

a. General. The ignition system is a conventional

eccentric on the engine camshaft to deliver fuel to the

12 volt battery supplied system and consists of a

updraft carburetor assembly.

distributor assembly, ignition coil, spark plugs and cable

assemblies and radio interference components.

e. Carburetor assembly. An updraft carburetor is

mounted on the left center side of the engine. The

b. Distributor assembly. The distributor assembly

carburetor consists of a die cast main body assembly

is mounted on the rear of the engine cylinder block and

containing fuel metering parts such as the idle tubes,

gear-driven by the engine camshaft. The distributor is

main well tubes, main jets, floats and fuel inlet valve.

fully automatic for control of the timing. A radio noise

suppression bypass capacitor is connected between the

f. Governor assembly. The governor assembly,

ignition coil positive terminal and ground. The only

located at the fan end of the engine, is of the mechanical

internal adjustment provided is the point opening. Proper

type and operates in conjunction with the carburetor

engine timing is obtained by rotating the distributor in its

assembly. The purpose of the governor assembly is to

mounting.

regulate engine speed under variable loads to protect the

engine against inadvertent overspeeding. The governor

c. Spark plugs and cables. Six spark plugs are

does not limit the power output of the engine: when

installed along the centerline of the cylinder head

loaded, the engine receives as much fuel as needed for

assembly. Each spark plug is shielded with a rubber

the load. When unloaded, the engine is protected

cover. Six cables connect the spark plugs to the high-

against overspeed damage.

tension outlets of the distributor.

1-10.

COOLING SYSTEM.

1-12.

STARTING AND CHARGING SYSTEM.

a. General. The engine assembly uses a pressure-

a. General. The starting and charging system

type liquid cooling system consisting of a rear mounted

consists of a starting motor, generator and pulley

radiator, water pump, thermostat, water manifold, bypass

assembly, generator regulator, radio interference

lines, drive belt and fan assembly.

components and a 12-volt battery.

b. Radiator assembly. The radiator assembly is

b. Starting motor assembly. The starting motor is

composed of a fin-and-tube type core with internal torque

located on the lower right side of the engine assembly.

converter heat exchanger, pressure-type cap, overflow

The starting motor is a 12-volt, 4-pole, 4-brush unit. The

tube and drain cock.

motor drive assembly, mounted on the armature shaft, is

provided with a pinion which is shifted by screw action to

c. Water pump assembly. A centrifugal-type water

engage the starter with the flywheel ring gear. When

pump and pulley assembly is mounted on the rear of the

engine assembly and driven by belt from the crankshaft