M50b25 Stroker Build List

[hellrot325]

Hi all,

I'm looking to stroke my M50 from a 2.5 out to a 3.0L. First off, I have an e36, and I know this is an e30 forum, but I have seen posts about this build before so I'm hoping I can get some information. My beamer is a '95, built 11/94 if that matters. I know I need an m54 bottom end, both crank and pistons. I plan on replacing the head gasket, head studs, piston rings, and probably bearings as well unless they're still good enough for my liking. Is there anything else I'm missing? I figure I'll probably need a tune as well to make it not run like shit, and maybe injectors too. This is going to be for an n/a build, so I'm not really worried about making it boost ready. I plan on using my stock m50 head and cams as well until I decide to upgrade those down the line. Will I need anything else to finish this build and make it run? Or is it as "simple" as replacing the bottom end internals>

[Northern]

As far as crank/rods/pistons, it's easiest to mimic an existing combo, which basically means M54 unless you want to oversize the bore.
Rings/gaskets/bearings. Main bearings usually seem to be in good shape on these, but size is the other issue.

If you have a complete engine you're doing this to, it's probably relatively straightforward to reassemble using all the original stuff + new gaskets.
Probably will find some broken stuff while you're in there - knock sensors like to crack on the OBD1 stuff. Also check connectors for corrosion and pull back the boots to see if the backside of the connector (and wiring) is intact. I don't know if this is just an M52 issue, but the cam sensor wiring tends to disintegrate at the connector. The M50 sensor is different, but I wouldn't be surprised if it has the same problem.

I'd throw some pink tops (21.5lb from M52B28 or S52) in there, and they should be good enough until you throw cams at it. Might need something a bit bigger at that point.
Try to talk to whoever is doing your tune first and see if they recommend something specific.