Event Narrative
The pilot reported that shortly after takeoff, a loud bang was heard, followed by a rattling sound and a loss of engine power. The takeoff had been conducted over water, and the pilot elected to execute a 180-degree turn to land downwind on the airport. The aircraft touched down at approximately the midpoint of runway 32R. Unable to stop, the pilot applied whatever power was available and became airborne again, clearing cars on a highway that crossed the departure end of runway 32. However, insufficient power remained to stay airborne. The aircraft subsequently touched down in a recently plowed field, where the right main landing gear was torn off and the aircraft nosed over.
Examination Findings
An examination of the engine revealed that the #6 rocker pin bosses were broken. A deep ridge had been worn into the interior face of a boss by a previous thrust washer, and an improper oversized washer had been installed that spanned the wear area. Additionally, a large quantity of water containing rust flakes was found in the carburetor bowl, fuel strainer, and right fuel line.