Incident Details
While in cruise flight, the aircraft's engine began to run rough. The pilot initiated emergency procedures in an attempt to regain adequate power. However, power was not restored, and the aircraft could not maintain level flight.
Forced Landing
The pilot executed a forced landing to a field. During the landing roll, the aircraft collided with a ditch, traveled approximately 20 yards, and nosed over.
Post-Accident Examination
Examination of the aircraft's engine revealed that a piston ring in the number 3 cylinder was broken. This allowed blow-by within the cylinder. No evidence was found to indicate that the aircraft's engine had experienced vapor lock.
Pilot's Statements
The pilot stated that he had encountered vapor lock. He informed an FAA safety inspector that he had used automobile gasoline for the flight and that the gasoline had been transported using 'old cans' from his father's house.