[cadillac_al]

I agree with post #4, it probably got hydrolocked at some time. It seems to me the piston must be making pretty light contact with the crank. If it was a harder contact the piston would break. The dilemma is to go cheap or go big. I don't know if I would look at that rod very closely and replace it, or bore the block and buy a rotating assembly. Tough call, I would try the cheap way first I suppose.