E30 Zone

Just completely tore down my M42 to reseal it and swap it in place of the M40 in my car. Came to find out there is far too much endplay and the crankshaft is ruined

According to realoem they have different part numbers but if I could use the M40 one it would save me from sourcing a new one or being tempted to build some kind of unnecessary stroker build.

I knew I should have just threw in the M50 I had for my other car.

They are very similar, but different at the front end. I can't remember what the difference was but I compared them side by side a couple of years back, the pulley end is a bit longer/shorter/machined to a different diameter or something. The actual crank looked identical apart from that.

The nose is slightly different, plus the M40 is iron and not steel.