Effect of Progressive Ring Failure on Piston Destruction

Two endurance runs were conducted on an Allison single-cylinder engine at high power output until destruction of the pistons occurred. Conclusions drawn are that complete failure of compression rings may require a long period of operation after initial failure, that complete failure of compression rings does not necessarily bring about destruction of the piston unless operation of the engine is continued for a considerable length of time, and that power loss accompanying high blow-by rates cannot be entirely accounted for on basis of gas leakage.