I would welcome ideas on what caused my engine to break. I pulled the plugs first and #2 was smashed. Pulled the valve cover and everything looked ok at first but one rocker on #2 was a little loose. pulled the intake and that pushrod was severely bent. Pulled the head and found the exhaust valve head sitting on the top of the piston which was very broke and pretty well jammed in the bore at TDC. The valve stem and spring and keeper are all still in the proper place on the head.
When I drained the oil I got about two gallons of water first. When the pan was off the #2 rod is bent and jammed into the bottom of the bore but still in one piece with the wrist pin still in place, The piston is obviously not connected.
I am thinking that the valve let go but what would cause this? Or is it possible I some how pulled the piston apart and it took out the valve? I had just gotten on the throttle when this thing let go. I didn't even get to 4000 rpm so I know I didn't over rev it.