Quote Originally Posted by winfred
the bores will not be worn unless this thing was turboed or supercharged and raced, it WILL still have hone marks on the walls from when it was built, i did a m20 that had 311k miles on it and i couldn't find a ridge with a knife and it had hone marks. the only way id screw with the bimmer short block would be if it got dammaged by rust with the head being gone and walls being exposed to moisture without being oiled, or it was overheated and the pistons started to melt and or seize (nasty up/down scoring/blue marking and aluiminum deposited on the cylinder walls) a couple of the builds i've done (last one was a m52 in a 97 528) were due to a blown headgasket allowing water into the cylinder and it sitting too long and lightly pitting the walls
If I wanted to add a turbo and intercooler to produce 350hp, could I simply change out the head for a referbed one to have a reliable car? Is there anything I should worry about in the bottom end?