Clutch question E to I swap

[E30Gus]

I am looking at the different Sachs clutches for my 2/86 325es. I should have the single mass flywheel and ordering the replacement clutch and pressure plate is a no brainer. I am installing my newer 91 i engine into my car and curiosity hit me when I started looking a the differences between the i and e clutch disc and pressure plate part numbers. My understanding is the the tranny (Getrag 260) and m20 engine block are pretty much the same in most e30's so why would there be a different clutch disc and plate for a 91 325i and an 86 325es? I think both have the 228mm disc. Is the 91 i clutch have more holding power or is it a spline/input shaft size difference between years/models of car? If they are all the same then would it be an "upgrade" to put in the 91 i clutch parts instead of getting the e parts?

Thanks
G

[jlevie]

The clutch to use on an M20 is determined by what flywheel you are using.If you use the flywheel from your M2oB27, you need to use that clutch. But when swapping in an M20B25, you should use the flywheel & clutch for that engine.

[E30Gus]

Ah thanks Jlevie! That makes sense. Besides the welded tab for the engine timing on the b27, I'm curious to know what is the difference between the two flywheels are.
On my way to the WTB section for a flywheel.
Rock ON!
G

[jlevie]

The flywheel for an M20B25 is lighter than the single mass M20B27 flywheel.

[E30Gus]

I'm getting confused after a looking for more info on these. I read that the single mass flywheel was lighter and more sought after because you can have it shaved/lightened unlike the dual mass. So is there 2 different kinds of single mass flywheels?

[jlevie]

Yes there are two types of single mass flywheels. The heavier one with timing pins was used of certain M20B27 engines. The other (with no timing pins) was used only on M20B25 engines, to the best of my knowledge.

[imwhyteyo]

if you have a dual mass, i have a brand new clutch in the box for sale.. much cheaper than what the stores asking. hell i could even give you the flywheel to mate with it if youd like to go that route. pm me if your interested.

[E30Gus]

My swap is complete as of yesterday! (-: I bought new Sachs disc and PP for the 325i fly wheel. I loved my eta but Dang this engine is sooooo much better being able to pull all the way up to 6k. And it sounds like a car with balls now! For any of you that have an eta and like it but looking for a little bit more, DO this and you won't be disapointed!
Thanks to JLevie and everyone else who has helped me along the way.
Best advise I can give is plan on a lot of time to do the swap and do your homework. Everything will go smooth if you have planned for it ahead of time.
G

[imwhyteyo]

are the throw out bearings between these two clutch systems the same size/ spec etc?... im curious because i have swapped from the dual mass, and only have a dual mass throw out bearing.