TOPIC 1. DESCRIPTION AND SPECIFICATIONS

TM 10-3930-644-14&P

TOPIC 1. DESCRIPTION AND SPECIFICATIONS

A. DESCRIPTION

drive is provided by the crankshaft timing gear. A gear

The engine (Figure 1-1) is a four-stroke-cycle and L-type

located on the camshaft drives the oil pump shaft and its

head design, with the valves arranged in the engine

coupled distributor drive shaft.

The fuel pump is

block. The main body consists of a single unit cylinder

actuated by an eccentric cam located towards the rear of

block and crankcase with integrally cast cylinders.

the shaft.

The aluminum pistons have four rings: The top two for

The main and connecting rod bearings are of precision

compression, the third for scraping and the three-piece

construction.

bottom ring for oil control. The full floating piston pins

are retained by snaprings.

The entire length of the heat treated, steel forged

connecting rods is rifle drilled for pressure lubrication of

The front drive gear is keyed and pressed in place, and

the piston pins.

is sealed to the crankcase by a die cast filler block. The

rear shaft extension is sealed to the crankcase by a die

The cylinder head is constructed of special alloy iron

cast oil guard and a filler block.

with carefully engineered water passages to ensure

optimum cooling.

The camshaft rotates in bearings located in the three

main crankcase bulkheads. Camshaft

The intake manifold has individual porting (Figure 1-2)

whereby each cylinder is fed with the fuel-air mixture

individually and not influenced by other cylinders of the

engine.

Figure 1-1. Cylinder Block Disassembled

M-104-1

2-1B