ARMY TM 9-2815-260-24
AIR FORCE TO 38G1-126-2
MARINE CORPS TM 09244A/09245A-14
c. Intake and Exhaust Valves. Intake and exhaust valves are operated by cam followers, push rods, and
rocker arm assembly. Valve seat inserts in cylinder head are used for intake and exhaust valves.
d. Crankshaft. The crankshaft is a one-piece, heat treated, steel forging which operates in replaceable two-
piece main bearings. The rear thrust bearing has a flange on each side to support crankshaft thrust and to limit
e. Cylinder Liners and Pistons. Cylinder liners are "wet" (surrounded by coolant) and are individually
replaceable. O-rings are used to seal the connection between cylinder block and liners. Pistons are made of
cast high-grade aluminum alloy with internal ribbing. The skirt is cam ground to allow for expansion when
heated during operation. The piston crown has a cut-out swivel cup with a truncated cone in the center. Two
compression rings and one oil control ring are used. The top compression ring is a keystone type ring. All
piston rings are located above the piston pin. The hardened piston pins are fully-floating and held in position
by means of retainer rings. Spray jets (piston cooling orifices) in cylinder block direct pressurized oil to
lubricate piston pins and cool pistons. Connecting rods are forged steel and have replaceable bushing and
f. Cooling System. The cooling system consists of a radiator, water pump, cooling fan, thermostat, and
connecting hoses. The fan and water pump are both belt driven from the crankshaft pulley. The thermostats
control engine temperature and are installed in top of engine. The function of the cooling system is to
maintain a specific operating temperature of 180 to 220°F (82 to 104°C) for the engine.
g. Lubrication System. The lubrication system consists of oil pan (sump), a gear type pump, full flow
spin-on oil filter with built-in bypass valve, oil cooler with built-in bypass valve, pressure regulating
valve, bypass valve, and the internal passages.
h. Fuel System. The function of the fuel system is to inject a metered quantity of clean atomized fuel
into the engine cylinders at a precise time near the end of the compression stroke of each piston. The
fuel system consists of the fuel tank, fuel filter/water separator, fuel supply pump, fuel injection pump,
and the fuel injectors. The fuel tank is not mounted on the engine. The fuel supply pump is mounted to
the block and is driven by the camshaft. The fuel injection pump is mounted on the front plate and is
driven by an intermediate gear in the timing gear train meshing with crankshaft gear.
Electrical System. The electrical system is 28VDC operation and consists of a battery charging
alternator, starter, externally mounted batteries, and other items as required. The battery charging
alternator is mounted on front of engine and is belt driven. When engine is operating, the battery
charging alternator supplies 28VDC to recharge the batteries and maintain them at a full state of charge.
The starter is mounted on the flywheel housing, and when energized, engages the ring gear of the
flywheel to rotate the engine.