M20 flywheel conversion

[gundy318]

I've bought a m20 flywheel that i had resurfaced and a 325i clutch kit that comes with a T/O bearing. Can i use that T/O bearing or do i need the one from the 323?

[asubimmer]

you will need the 323 tob

[gundy318]

alright thanks

[Vladi]

I used my M40 TOB and it works. :confused:

[D. Clay]

I used my M40 TOB and it works. :confused:
In realoem.com, the part numbers are the same for an E30 318is and and a 323i. From that it appears that the 1991 E30 318is TOB should work with the M20 Flywheel and clutch.

[nickmpower]

noooo

[D. Clay]

What is the part number of the TOB for M20 flywheel and clutch swap?
realoem shows
21517521471
as the part number
for 90-91 318is, 323i, anfd the Euro M40.

[2002maniac]

seems like the M20 flywheel swap can be alot simpler than we all though! I'm stoked!

[2002maniac]

What is the part number of the TOB for M20 flywheel and clutch swap?
realoem shows
21517521471
as the part number
for 90-91 318is, 323i, anfd the Euro M40.

no, I just checked realoem and it's the e21 323i TOB we need (or do we?)

21511204525

The one you found is for the e30 323. it is also the same as the e30 325i and many others.

[nobrakese36]

The clutch we use is out of the 325I not the 325e right?

[gearheadE30]

its out of the 325i/is

edit:
yes, it is the E21 part that is needed

[stuartgallafant]

i have this mod to do on my iS too. why do you need the E21 323i T/O bearing? will the M20 one not work? i was under the impression that all M20 clutches and release bearings were the same

[odbod]

I have just put my engine and gearbox together using an lightened M20 Flywheel, 325 Clucth, 323 TO Bearing (which is actually used on 320's as well, but the dealer told me it was only on really early cars) and the engine has gone in to the car today, can't wait to get it running it's only done 37K Miles!:)

I have piccies comparing the IS, 325 and 323 T/O bearings if someone can host them I will post them up, they are quite different, you can see why you need the 323 bearing as it's quite a lot longer and the tabs are in different places.

[m44power]

I used my M40 TOB and it works. :confused:

i used my TOB e36 318is too it works great

[kramerica5000]

Does anyone know if you can re-use the bolts from the m42 assembly to attach the M20 pressure plate to the M20 flywheel?

[gearheadE30]

I would assume that you could, although bolts aren't super pricey and it may be a good idea to just replace them while you're in there.

[odbod]

They are the same, M8 x 16mm.

[1991 E30 M42]

They're 12x1.5


No. Description Supplement Qty From Up To Part Number Price Notes
01 TWIN MASS FLYWHEEL 1 21211223550 $859.32
NOT SUITABLE FOR
TWIN MASS FLYWHEEL
02 DOWEL PIN 10X23 3 11221709069 $3.24
03 DOWEL D=14,5MM 1 11111743118 $1.67
04 COLLAR SCREW M12X1,5X25 8 11221717841 $1.67
ONLY APPLIES TO
TWIN MASS FLYWHEEL
04 HEX BOLT M12X1,5X50 8 11222243051 $2.34
05 GROOVED BALL BEARING 15X32X10 1 09/1990 11211720310 $20.76

Notes:

[1991 E30 M42]

Never mind, I was thinking about the wrong bolts.

[m44power]

Does anyone know if you can re-use the bolts from the m42 assembly to attach the M20 pressure plate to the M20 flywheel?
do your self a favor and change the presure plate bolts what would be good for the next time you want to remove your pressure plate as for the flywheel bolts (M20 bolts or machined m42 bolts 20mm long for 325i flywheel or 25mm long for Euro 320i flywheel) keep the same just use some Loctite

[Vladi]

I have piccies comparing the IS, 325 and 323 T/O bearings if someone can host them I will post them up, they are quite different, you can see why you need the 323 bearing as it's quite a lot longer and the tabs are in different places.

How can we see the pics? I'm very curious!

[odbod]

Throw out / Clutch release bearings from left to right

E21 etc 323 E30 318IS E30 325i

http://img143.imageshack.us/img143/5696/dsc00030jf4.jpg

[m44power]

thats why my clutch release to high? :(

[romkasponka]

thats why my clutch release to high? :(

You can increase rod lenght on clutch cilinder...

[jpod999]

Ok so someone that has done this needs to put together a list of all the parts they used to make it work.

[odbod]

Right here goes then...

Required:

1 off M20 325 Flywheel (the thin one) - Modified as below
1 off Starter motor to match the above (or pinion assy)
1 off clutch kit to suit the above
1 off Clutch release bearing (21511204525)
6 off Flywheel bolts - If you are being absolutely complete (11222243051)
6 off Clucth Bolts - M8x16mm long (07119919939) grade 8.8 (I Think) but you might as well fit 12.9 or 14.9 (as with the flywheel bolts you can re-use the originals)

Optional: - Might as well as they leak eventually...
1 off Clutch slave Cylinder
Brake/Clutch fluid

The flywheel has a lip on the engine side that may foul the engine and most have it machined off, it also gives the added bonus of lightening the flywheel!

I have included some piccies below for reference

M20 Engine side
http://img516.imageshack.us/img516/7430/dsc00296nt4.jpg

M42 engine side
http://img526.imageshack.us/img526/1033/dsc00297nm0.jpg

Flywheel on engine, not very clear but does show the lip has been machined back to the edge of the ring gear (and some extra has been taken out of the face)
http://img526.imageshack.us/img526/9831/dsc00034uq1.jpg

[m44power]

You can increase rod lenght on clutch cilinder...
how ? :D

[romkasponka]

how ? :D

you can cut and weld it, or cut thread rod and make threaded sleeve..

[AL GReeNeRy]

has anyone used a lightened flywheel with the m20 coversion? i like the fact that m20 lightweights are only 8 lbs compared to the m42s 9. and the m20s is cheaper by about a hundred bucks!!!

[m44power]

you can cut and weld it, or cut thread rod and make threaded sleeve..

can anyone mesure the different of 2 TOB for me ? how much longer is the E21 TOB ? just to know how much i have to add in my clutch cylinder

[kramerica5000]

...
The flywheel has a lip on the engine side that may foul the engine and most have it machined off, it also gives the added bonus of lightening the flywheel!
...



Did you (or can you) just have this done at a regular machine shop or is this something that you have to take to a performance shop that specializes in lightening & balancing flywheels?

[odbod]

You should be able to take it to a regular machine shop, but check they are good and make sure that the wheel is clocked up and runs true before you start machining. Whether you also have it balanced is up to you, i didn't because I trust the guy who did it and the wheel ran perefectly true before machining.

Runs great with no vibrations so must be ok!

At the same time I had som more removed from the back face to get rid of some more weight!