QUESTION about M52 engine building

Moderator: martauto

Post Reply
linsChaho
E30 Zone Newbie
E30 Zone Newbie
Posts: 2
Joined: Wed Aug 18, 2021 7:19 am

Wed Aug 18, 2021 7:45 am

Hey, Currently I have an M52B20 and whilst it'd be THAT much easier to simply swap it for an M50/52/54 B25/28/30, I am advised to not do so. They take modifications pretty strictly over here so I'm trying to see other ways of upgrading which are virtually invisible.

I'd like to to increase bore and stroke too. Stroke is obviously doable but I have my doubts about boring it. So currently it has an 800mm bore and all the bigger engines have 84mm. Question is whether you can bore it up to that size AND maintain a safe / same as stock cylinder wall width.

So if I were to bore it to 84mm, would I end up with the same cylinder wall thickness as if it was a stock B25? ( That follows that the B20 actually has thicker walls just because of using the same casting ) Kind of same as asking if they used the same casting for B20 as B25?

Otherwise the plan would be to bore it, make it a stroker and use M54 sleevings (iron instead of nikasil), M50/52 oil rings etc.. Use the best of all 3 worlds.

Thanks!showbox speed test
Last edited by linsChaho on Sun Aug 22, 2021 2:06 pm, edited 1 time in total.
DanThe
E30 Zone Team Member
E30 Zone Team Member
Posts: 28640
Joined: Sat Sep 10, 2005 11:00 pm
Location: Staffs
Contact:

Wed Aug 18, 2021 9:26 pm

If its a nikasil block to start with it will be a lot easier than using a block that has liners in. The heads are different too so you would need a 2.5 or 2.8 head
Post Reply