E30 Zone

Posted: **Sat Mar 17, 2007 4:52 am**

Hi team,i have a question to ask?I want to overbore my m20/b25 block to 86mm,what BMW pistons will fit from another BMW model if any.I would prefer to use BMW pistons but i'm open too suggestions,thanks Kiwi Pip.

Posted: **Sat Mar 17, 2007 9:40 am**

I may be wrong here, but AFAIK anything beyond 84.5mm (standard maximum over-bore) is pushing it in a M20 block. There's very little metal left between the bores and water jackets beyond that point.

E30 Zone

m20/b25 overbore.

m20/b25 overbore.