Pistons are oil cooled by an oil spray through a separate pump provided for this purpose. Pressure lubrication is supplied to all important points and the oil is properly conditioned by passing through filters and cooler. Connecting rods are drop forgings of fork and plain rod construction to eliminate cylinder offset and improve bearing conditions. The two-cycle principle permits a simple cap design, allowing removal through the cylinder liners of connecting rods with a large crankpin diameter. The carbon steel crankshaft is drop forged with electro-hardened journals, permitting the use of copper alloy crankpin bearings and special babbitt main bearings.
All bearings are precision made, eliminating hand fittings.
The Unit Fuel Injection System employed is a principal and patented feature of GM Diesels. Each cylinder is fitted with an individual injector unit which constitutes an independent and complete injection system operated from the overhead camshaft. Complete and accurate control of the fuel injection, timing, and atomization, combined with complete blower scavenging, result in high efficiency, clear exhaust and smooth operation.