Engine-Lubricant Compatibility Tests on MIL-L-21040 Oil Using Engine Model 6V53T.

A high-output two-cycle diesel engine model 6V53T was subjected to a targeted 210-hour laboratory-dynamometer endurance test cycle using three different MIL-L2104C SAE grade 30 engine lubricants. The significance of this test procedure is such that it was shown to relate to vehicle performance during the early 1960s. Current laboratory engine test results show that this engine may not be compatible with all MIL-L-2104C lubricants when operating with reference Number 2 diesel fuel 0.42 percent natural sulfur. This is based on the observation of severe piston, ring, and liner scuffing and scoring with one lubricant, and borderline acceptable performance with a second lubricant. Only one lubricant tested demonstrated desirable high-level engine compatibility. Recommendations for additional testing are made. Author