The only thing I didn't check, I've never checked and didn't know I needed to, was the crank counter weight to piston clearance.

This was a K1 Hemi 4.15 stroke crank and in the first motor I used it in we cut the counter weights down besause it needed so much weight taken off of it to balance it.

And then when I hurt the motor last fall I had it offset ground to 4.25 and Chevy journals. So with the 7.100 rod and shorter pistons there must have not been enough clearance. It would turn over by hand just fine but at speed it must have been making clearance on the pin boss on the piston as they stretched and the piston let go.

That's my theory right now and until I tear the motor down and hopefully verify what happened.

Pistons are off the shelf diamond 4.25 flat top but with 4.440 bore.

So depending on what the damage is I may put Frankenstein aside and focus on the KB motor but I'm hoping it just got a piston or two and maybe a rod. But I think it also bent a valve on each side.... To be continued.