Morris Minor Owners Club

I'm preparing a 1098 Midget engine for a rebore and can only find a B stamped on the pistons. What size would this indicate, thanks, John

'B' doesn't mean anything regarding size. You need to be looking for '010', '020', '030' etc. Sometimes standard ones say 'STD', but don't always say anything. If you've got them perfectly clean and can't find anything, then they're most likely standard size. But best to get the bores measured to be dead sure.

Its just a 'grade' mark -means nothing now.

If you're going to have the block rebored it doesn't matter what size pistons are in it now. The shop thats going to do the rebore for you can measure the cylinders and tell you what size they are now and what size it will be rebored to.