Initial Symptoms
The pilot reported that while cruising at an altitude of 4,000 feet MSL, the engine power began to fluctuate. This was soon followed by a banging noise, rough engine operation, and a decline in power output.
Pilot Actions
The pilot turned to land into the wind. At that point, the engine power increased and stabilized. Believing he could reach a highway, the pilot turned downwind. However, a short time later, the engine stopped completely.
Landing
With the engine inoperative, the pilot was committed to landing downwind and downhill. During the landing, the aircraft nosed over.
Post-Event Examination
An engine teardown was conducted. The examination revealed that the number four exhaust pushrod, part number 630393, had failed.
Weather Conditions
The wind at the time of the event was reported to be gusting to 35 knots.