Engine Failure and High Speed Knock

High speed knock is one of the major obstacles to higher compression ratios and, consequently, lower fuel consumption.

The relationship between engine failure and knock intensity was studied by testing a European engine at 4,000 and 5,000 rpm, on full throttle. Endurance test results show that the knock intensity which causes damage decreases as speed or combustion chamber temperature is increased.

Other information obtained through analysis of the type of engine failure has suggested a way to increase compression ratio without changing octane requirement.