ginge you dont need much engine building experience to know that a huge lip on a top of a bore is not a fresh engine when it should have a new oil pump etc? and the only reason why that engine was slapped together was so he could drive as he had no money after that "rebuild". my idea of a rebuild would be rebored, balances, wit new pistons, rings, pumps etc, but when you let a car warm up ragging it shouldnt matter to much within reason, he only had the odd tear up, not constant, which id thought the gearbox would let go first?