E30 Zone

i saw a post on here quite a while back about how the older 325i m20 had high compression ratio than the newer m20 and it said hw you could tell which m20 had the high compression, i cnt find the thread does anyone know what it was called ?

Cant remember what the thread was called but if you look above the distributor end of the exhaust manifold there is a small raised round section.

If this says 2.5 it is a high comp engine, If it says 2.5 2.7 it is low comp.

This is to the best of my knowledge anyway.

Have a look at the engine number
84B25E is the 9.75:1 CR variant 84B25K for 8.8:1

Here's the thread: http://www.e30zone.net/modules.php?name ... 97&start=0

thanks for that mate