M52 swap Shaved Flywheel starter question

[Bmrlvr4lfe]

Hello everyone

87 325is
Getrag 240 manual
325i flywheel shaved approximately 5/8 inch
m20 starter

So I put it all together, dropped engine and transmission in. I installed the starter and the m50 intake.

I put the oil in and went to turn the crank shaft and it was frozen, it did not move. I made sure it was out of gear and tried again nothing.

The engine was running when I pulled it. I’m looking for any thoughts from the group. My thought is that the starter is hung up on the flywheel because of the shaved flywheel.

Any thoughts would be greatly appreciated!

Ben

[jbontke]

Starter must match fly wheel: m52 starter with M52 flywheel, or m20 starter with m20 flywheel. Remove the starter and see if the engine will spin. My guess is the flywheel is touching the back of the engine block.

[e30austin]

the flywheel must be shaved down to the ring gear. any less and it's too close to the oil pan and will touch. as above, make sure your starter and flywheel are a matching pair.

[mtech325]

On this topic, does using an m20 single mass flywheel with a transmission originally equipped with a dual mass flywheel (g240, ZF320, etc) require a different throwout bearing like the e21 323 unit? Or are there any downsides in terms of clutch release/engagement to using the stock m20 325i throwout bearing that usually comes with the clutch kits?

[e30austin]

On this topic, does using an m20 single mass flywheel with a transmission originally equipped with a dual mass flywheel (g240, ZF320, etc) require a different throwout bearing like the e21 323 unit? Or are there any downsides in terms of clutch release/engagement to using the stock m20 325i throwout bearing that usually comes with the clutch kits?

generally speaking, yes. the 323i unit is ~5mm taller, allowing for proper engagement/disengagement, in single mass conversion situations. not *every* type of flywheel conversion utilizes the tall release bearing, but a lot do.

to boil it down, if you buy an e36m3 single mass flywheel conversion, you've got two styles - the thick (twin mass replacement) single mass unit, and the skinny (conversion) unit.
the thick unit uses the e36 m3 pressure plate (slim) and an e34 m5 clutch disc (sprung), and is effectively not much different than the twin mass setup.
the thin unit uses the e34 m5 pressure plate (large) and clutch disc. the thin style would use the tall release bearing to compensate.

[Bmrlvr4lfe]

Starter must match fly wheel: m52 starter with M52 flywheel, or m20 starter with m20 flywheel. Remove the starter and see if the engine will spin. My guess is the flywheel is touching the back of the engine block.

Thanks jbontke&e30austin. it’s a m20 flywheel. So your saying I may have had the flywheel shaved down too far? I’m not sure what the ring gear is or what it looks like? Anyone have a picture of it? Thanks again!

[e30austin]

Thanks jbontke&e30austin. it’s a m20 flywheel. So your saying I may have had the flywheel shaved down too far? I’m not sure what the ring gear is or what it looks like? Anyone have a picture of it? Thanks again!

what i mean by that is, you need to shave the back of the flywheel down completely... if there's any more than 1/8" material, it'll contact the oil pan. don't remember exactly how thick they are from stock, but that's what you need to know.