[Ron61]

Toby,

It would be rare, but any part can fail no matter what it is or who made it. Not saying it was a piston failure for sure, but from all the evidence it sure seems to point in that direction. Trularin gave some good reasons this could have happened but if it was the rod hitting the edge of the cylinder wall, then all of them should have did it and there should be marks. The fact that only that cylinder showed any sign of problems would sure make one think it was a piston or valve problem. But the valve could have been stuck from the piston hitting it and bending the push rod. Most likely you will never be able to pin point exactly what happened as you don't have the piston or it's pieces.

Ron