Engine: Description and Operation

The diesel engines used on these fullsize pickup trucks are the 6.2L/V8-379 and the turbocharged 6.5L/V8-397. In the diesel engine air alone is compressed in the cylinder. After the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition occurs due to the heat of compression. Due to the increased compression and resultant increase in combustion temperatures, major differences are evident in the cylinder heads, combustion chambers, fuel distribution system, intake manifold and engine mechanical components.
The cylinder block, crankshaft, main bearings, connecting rods, pistons and wrist pins are all heavy duty designs, due to the higher compression ratios, and the main bearing caps are 4 bolt design to provide rigid crankshaft support, while minimizing stress. Roller hydraulic lifters are used to minimize wear on the forged steel camshaft, and intake and exhaust valves are of special alloy material to combat the higher internal operating temperatures. Steel alloy prechamber inserts are installed in the combustion chambers and are serviced separately from the cylinder head. Injector nozzles and glow plugs are threaded into the cylinder head to allow direct fuel delivery and to provide chamber preheating.