Originally Posted by boy-racer-1

i built my engine to a completely standard spec and the pistons were above the blocks deck height and at the time i was told this was normal, dont know if having your pistons 1mm lower then the height of the deck will cause you any troubles but will surely give you a really low compression?

Originally Posted by J1mbo

It's not good practise to stop pistons down the bore but it will be fine. Now yove removed 1mm from the top the bowls in the piston will have lost capacity so make sure you measure the compression ratio and not just guess.