Clutch question

[evangreen]

Im swapping over to a zf trans and i figured I'd change the clutch when im in there. Found a good deal on a slightly used southbend stage 3 clutch.

I called southbend but they werent sure if it would work

came from an m50 with a 250 getrag, stock fly

going into m52 with zf320, with m20 lightweight fly

I was under the impression that the m20 and m50 flyywheels were the same size and that this would work, but i just wanted to check here first

thanks
Evan

[balooshinakus]

Pretty sure your flywheel/clutch need to be from the same motor, 24v clutches are bigger.

[evangreen]

ok cause the sachs clutch is the same for pre 87 e30's as m50 clutches.

I know that in 96 the changed but i thought that the m20 and m50 flys were the same, can anyone confirm or deny this?

[MR 325]

M20 single mass flywheel and M50 flywheel are definitely not the same.

[nando]

you can use an M20 FW with the M50 engines. You just have to match the clutch/PP to the flywheel.

[Wh33lhop]

Here's the skinny.

M20B25 flywheel is single mass, M20 clutch is a sprung-hub.

the DOHC flywheel is a dual mass (sprung mass is part of the flywheel) and the M50 clutch is an unsprung-hub.

Even if it did fit, you would have no sprung mass in your bellhousing and that would probably make the clutch action very harsh and cause a good bit of chattering. But I don't think M20 and M50 flywheels are interchangeable. Some etas had dual-mass flywheels but I don't believe they are interchangeable either. Keep the M20 flywheel, it's a lot better than the DOHC dual mass waffleswaffleswaffleswaffleswaffleswafflesry. I'd just stick with an OEM clutch (IIRC the M20 clutch holds fine for S5x torque so it'll probably be good with the M52) unless you're hell-bent on chirping third.