M10 Flywheel on an M42

[ash00]

Anybody try this? I know the popular thing to swap is an m20 flywheel- but whats the difference in the M20 and M10? Im having a hard time locating an m20 single mass, but someone suggested an m10....

[skipsfcr]

Ash, that was my suggestion and I just tried it. I happen to have an M42 short block in the back of the shop. I hung an M10 flywheel on it and the locating dowell and bolt holes line up perfectly. Looks like it'll work to me.

[ash00]

Yeah, I was referring to your post-- THANKS!

I'm checking out a M10 flywheel today and if it works then SWEET!

What do we do for the clutch? Stock M10 or M42?

How about the ring gear for the starter? Same as the M10, or use an M10 starter?

[Tommy]

Ring gear is different for m10 and m20. Maybe m10 starter will work, don't know about that though.

Tommy

[jose3523]

Skip I'm looking for struts for my 1967, 1600 and was wondering if you might have some around that you're not using? You helped me on a transmission when someone wouldn't send it to me after I sent him the money.

jose3523@juno.com

[antiaem]

anyone follow up on the ring gear question? im in the process of an m42 swap and this would be very useful. ive heard a single mass makes a world of difference in the m42.

[ash00]

im going to look at a m10 flywheel today hopefully so I'll let you know

[antiaem]

that would be awesome thanks

[Harland]

BUMP!

So has anyone succesfully used the M10 flywheel in an M42?

[skipsfcr]

Wow...blast from the past. I did try to use an 1984 M10 E30 318i 215mm flywheel. Very light. Lighter than a 2002 215mm flywheel. Bear in mind it's been awhile. If I remember correctly the issue I had with that particular flywheel was that the back spacing made it barely touch the rear main oil seal holder...barely is too much... It locked the motor up! In the interest of getting the car on the road I went ahead and used the dual mass from the M42. She's a tire spinner! Since an M20 228mm flywheel is known to fit an M42 I'm sure a 228mm M10 flywheel will work also.

[ash00]

Yah really...good updates though.

[TobyB]

Problem- M10 starter has different pitch gear teeth.

I tried using an M20 flexplate, and between the different diameter

of the ring AND the different teeth, it got messy.

You might be able to put an M20 ring gear onto the M10 flywheel-

I didn't have that option.

t

[4x2]

You might be able to put an M20 ring gear onto the M10 flywheel-

I didn't have that option.

Or put the M42 ring gear on the M10 flywheel.

I did just that with a M50 ring gear (same as M42) on a M10 flywheel.

The M50 ring gear is a bit smaller, but nothing a lot of heat can't fix.

[Harv]

What about switching the starter gear?

John

[vpilarry]

What about switching the starter gear?

Don't think that's possible w/o a lot of work. The M20 323i flywheel (FW) is only a half lb or so heavier than the M10 FW (which is ~13 lb). They come up for sale periodically in the E30 forums for $125-$150. I've got one on my E30 M42 and can definitely tell a difference from the M20 325i FW I had before. Of course the M20 325i FW can be shaved/machined down to the 13 lb range but that adds cost. Be aware that any swap from the M42 dual mass FW requires the use of the M20 323i TOB and M20 325i FW bolts as well as a late model M20 325i starter or a swap of the M20 starter bendix into the M42 starter.