As I mentioned in the other thread I have had a few split Cleveland cylinder walls over the years. What I forgot to mention was the very first split cylinder I had was a cast piston combo in my very first Cleveland build (that is IIRC lol). And if I do actually remember correctly the split cylinder on that engine did have a busted piston skirt too (did I mention I really hate cast pistons lol). So I guess that is another possible cause for a split cylinder wall (Cleveland an others) from either piston rock after the skirt broke off, or the piston/skirt somehow getting wedged for a split second as it broke off.
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