[Ron61]

Toby,

The water theory is ok except for one thing. Just a lot of pressure wouldn't have smashed the end of the sparkplug. The white smoke sounded almost like water, but if the gaskets were good and there was no crack anywhere, then that most likely came from water pouring in after the big bang. Also something stuck the valve and that sounds as if it had been hit. With the piston gone there is no way to look at the wrist pin and see if it broke or gave way. From all that you have seen, it sounds as if you may have just had a bad bit of luck with that one piston. And the fact that it ran good for a while tells us that everything was clear and the pistons weren't hitting. If there had been any clearance problem, all of them would have had it and you would have known it immediately after starting the engine. This part from experience of watching a guy I knew when we were younger starting his 1958 Chevy after putting in a big cam and not checking his clearances. It ran almost 30 seconds and broke everything. Are you going to try to sleeve that block or get a new one?

Ron