m42 siongle mass flywheel

[3bvert]

dont remeber where I read it, cant find it now, cant find in search unless I did it wrong

I read that pre 3/91 build date that the m42 came with a single mass flywheel

is this true ?

I have a 11/90 m42ic and a 7/90 m42is parts car

this winter I will need to do a clutch, and thought of doing the m20 stuff, but if I have a single mass I can shave down, then I prob wont start looking for a m20 and conversion parts needed

[KenC]

Both of yours have a dual mass.

[cepa318is]

i think the single mass was a euro only option. there was discussion on m42 club

[dvmotorsports]

No. Dual mass came equipped on all M42 motors world wide. Get the 323 Euro FW and clutch kit. As well as the starter pinion. The FW is 11.9lbs. You will get some noise out of it (which is why BMW went dual mass from the get-go) but it is well worth it.

[FredK]

Non-AC M42 engines received a single mass flywheel. It weighs 22lb, in comparison to 27 lb.

PN 11221739315, clutch PN 21211223570.

More info here:

http://www.e30tech.com/forum/showthread.php?t=55835

[3bvert]

thanks
thats exactly the write up that I had read and could not find again

now to find a euro flywheel

[tjts1]

You can also use an M40 non AC flywheel if you are looking in Europe.

[dvmotorsports]

The weight would explain the attempt to dampen, but I just have a hard time believing that after everything I have looked at. I have never seen a SMFW on a stock M42. I'm not buying it without more proof.

[M42Technik]

An excerpt from Stu's old article:

"Flywheel - A major problem with the M42 was that it had BMW’s 'dual-mass’ flywheel; yes, it weighs almost twice as much as a 325i flywheel (as the name would suggest), at 28.5 pounds. This is a big problem and absolutely kills 1st and 2nd gear acceleration. Ever wondered why your 318iS’s 0-60 was so slow? Well, the flywheel is one of the reasons.

There are 3 options to fix this: 1) use a 325i flywheel/clutch or 2) buy an aluminum flywheel for your M42's clutch, and 3) an aluminum flywheel for using the 325i clutch. Buying an aluminum flywheel for the M42 runs about $500-700 but is very light, and requires no modification to be fitted. M42 aluminum flywheels are about 12 pounds, and 325i aluminum fly's are about 8 pounds. The 325i flywheel requires a few other modifications to be fitted in the 318iS.

Here’s what you need: 325i flywheel, 325i clutch, 325i pressure plate, 325i drive-pinion for the starter motor, and a ‘78-’83 323 throw-out bearing. Replace all these with the 318iS parts and it bolts right together. After all is said and done, your 318iS will have a LOT better acceleration in the first few gears, and deceleration will take place much quicker, which helps on the street and in the auto-x. "

Hope that helps.