SECTION III: PRINCIPLES OF OPERATION
TM 9-2350-256-20
NOTE
The following callouts are found in Figure 16.
The engine features a fuel injection system and a turbosupercharged, air induction system. The fuel injection system
utilizes a fuel injection metering pump which supplies metered fuel to individual cylinders through fuel injector nozzles.
The fuel pump assembly (22), located at the front of the engine, delivers fuel to the injector pump. A turbosupercharger
(7 and 29) is located on each side of the engine at the rear. The turbosuperchargers are exhaust-gas driven and
increase the airflow pressure entering the air intake manifolds. The engine is equipped with a 28V, 300-A, dc generator
(9) and a 24-V, solenoid-operated starter (34).
The engine is lubricated by a forced-feed system. The system consists of three circuits: the scavenge circuit, the main or
pressure oil circuit, and the piston cooling circuit. These circuits are operated independently by one oil pump, which
consists of four separate pump sections.
The engine is equipped with two intake manifold heaters (15 and 33) which are installed in the air intake system between
the intake manifold elbows and the turbosuperchargers (7 and 29). The heaters, when operated, preheat the air entering
the cylinders to facilitate cold-weather starting and cold-weather idle operation.
The engine crankcase is vented by the crankcase breather system which exhausts through the crankcase breather
tube at the left turbosupercharger exhaust outlet.
The engine primary fuel filter (2) and fuel/water separator-type secondary fuel filter (26) both have top-mounted bleeder
valves to assist in the removal of air from the fuel system. Water is removed automatically by a constant-bleed orifice in
the primary fuel filter and an automatic water drain in the fuel/water separator fuel filter.
1
Oil filter bypass valve
3
Engine oil cooler thermostatic bypass valve
5
Oil pressure warning switch
2
Primary fuel filter
4
Oil pressure gage transmitter
6
Oil pressure regulator valve
Figure 1-6. Engine (1 of 4)
1-17