Piston Marking Question

Hi all,
Probably a really daft question but wanted to double check.
I have an early mk2 engine that’s has been sat in a shed for 25 years. I know it’s had some work done but not 100% sure what.

Pulled the pistons and they have a 0.030 mark on them. Can I assume the block has been bored and these are 0.030 oversize pistons?

I found a score in one of the bores so looks like a further bore out is needed and new pistons. Thinking Mahle 0.060 oversize but any advice greatly received.

Thanks all and Merry Xmas


You will need to do something about that score line. From the photo it seems like a small pit or hole in the bore near the top of that score line, can you check it.

Welcome to the forum.


Definitely over bored to +30 I would countenance against going to +60 that ultimately will require the block to be sleeved by the next custodian in 50 years time.
I must agree that the top of the line looks odd.

It looks to me like something sat in the hole at the side of the piston but agree doesn’t look good. I intend to take to an engineering shop to get checked.
I suppose another option is together all re-sleeved but not sure how practical that is.

Stage one was to confirm my suspicions a bore had taken place already.

Thanks for the advice so far and will keep post up to date but is going to be a couple of weeks till I can get it looked at.

I think maximum rebore size is +030 , advised !
but see you can get +040 .