m20 flywheel surfacing?

[drken]

That is helpful to know. Although I didn't measure mine, 11 thousandths isn't much, so I think as long as I can feel it, it must be close.

Ken

[smooth]

There needs to be a proper step on the flywheel.

I have read that BMW does not list a specification but when I dropped mine off at the local machinist's last week I found the spec of 11 thousands of an inch in his book for him.

[drken]

Whew... false alarm. I yanked the trans back out, and the mating surface is still "proud" of the rest of the flywheel..:D I guess the old memory isn't what it used to be...
Thanks for the help, though!

Ken

[justin_l_]

http://www.e30tech.com/forum/showthread.php?t=113958

[drken]

That's what I'm thinking so far. I'm afraid it might reduce the clamping force, and the s52 is pretty torquey. I think I'll pull it back out tonight unless somebody has had experience to the contrary.
Ken

[justin_l_]

There needs to be a proper step on the flywheel. I don't remember what it is off the top of my head. If he only machined the clamping surface and not the pressure plate locating surface as well I'd have it redone.

[drken]

Hey all,

I recently had my M20 flywheel shaved 3/16" on the back to clear the m50 oil pan. The machinist also "freshened up" the clutch mating surface of the flywheel "just enough to break the glaze". I didn't ask him to do that, so now I worry if clamping force will be lost. Anybody experience this? This is for a stock OBD2 s52 with a G260 in a track car.

Also, I don't recall whether that clutch surface used to be slightly recessed into the flywheel, or did it used to stand above the rest of the flywheel?

The tranny is already bolted back on to the motor, but I'm hesitant to finish everything else up until I get a better feel for if this is going to cause a problem.

Thanks for answers!

Ken