Flywheel question...

[TDE30]

325i flywheel and 325e flywheel, are they the same?

Help is appreciated.

[justin_l_]

Depends. Some were dual mass and some were singal mass.

[Aptyp]

Simple answer. No.

[rThor432]

Semi in-depth answer--

Early eta's had a heavy single mass flywheel that was essentially the same as the later B25 flywheel, although it weighed about 4-5 lbs. more. The early eta flywheel is 23 lbs iirc. The B25 flywheel weighs about 19 lbs.

The late eta had a dual mass flywheel, that weighs a ton and just sucks. It weighs around 27 lbs.

[TDE30]

Ah, okay. Thanks for the information.

[Rob]

Ryan, so a supereta would have the heavy dual mass? Meaning even a stock 'i' fly would be an upgrade...

good info!

[DCColegrove]

The I flywheel wont have a TDC ref mark for the old 25 pin DME sensor.

[Flash]

The early 528e flywheels were 13 pounds AND had a TDC pin!
You can duplicate that by shaving the engine side of the flywheel down to the level of the ring gear but then leave about .010 of a lip, no TDC pin however unless you put one on.

[rThor432]

The early 528e flywheels were 13 pounds AND had a TDC pin!

I've got one of these in the command center.

Yeah Rob, all 9/85 and later etas have the giant flywheel. Even the earlier eta single mass flywheel is an upgrade (that's what I had in my eS). Mine was used with a B25i clutch and pressure plate. Worked good.

I weighed all of the flywheels one night at Mitch M's shop on a postal scale. The early 528e/320i/323i flywheel weighs 13lbs., the early eta flywheel weighs 23lbs., the late eta weighs 27lbs., and the B25i flywheel weighs 17 or 19lbs (pretty sure it was 19lbs).

[E30SPDFRK]

Will a late eta clutch bolt up to a early 528e flywheel?

[Flash]

All the bolt patterns are the same for the m20 flywheels, the question is will the stack height be the same.
The pressure plate is a lot thicker for the 325i to make up for the shorter flywheel, realoem would tell you if the part numbers are the same anyhow. Dual mass does not use a sprung hub since the flywheel is spring, and single mass....vice versa.

[Mike]

interesting, how about those 323 ones?

[cobraken]

Uh, can someone help me out on this? I am getting ready to install a 325i engine in my 86 325e and dont fully understand the flywheel issue.

Assistance is needed.

[cobraken]

Here is my VIN if this helps WBAAB5407G9634771.

[jlevie]

You need a single mass flywheel from a 325i/is, matching clutch, pilot bearing and throw out bearing.