Flywheel / Transmission questions

[Oakman]

I've read the wiki, searched, etc.. and I still have a few questions before I start this swap into my 91 318is w/ M42.

I will be picking up an M50B25 on Saturday from an E34, and I will be using my G240 that's currently in my car, and for the time being my open 4.10 diff. So from what I understand I don't need to do anything with the engine, but I do need a brake booster from a Porsche 944 (seems to be the cheapest and easiest to find on eBay), E28 535i mounts from eBay, and E36 motor mount arms. I already have a brand new rad w/ electric fan in my car to make that part easier.

So that being said what I'm not 100% sure on is whether I can use the M50 or M42 flywheel. I've read people doing it and saying not to do it, but I can't find any explanation why I wouldn't want to. Seeing as I'm pulling an M42 out and not an M20 I don't want to buy an M20 flywheel and starter, and bearing, etc... if I don't have to.

The other question is on mounting the transmission, the wiki says I can use the stock transmission crossmember & mounts, yet I need a different drive shaft? Maybe I missed something, but I don't quite understand how I need a different drive shaft if the transmission is in the same place.

I think that should be it, I'm going to a bunch of pick and pulls on Saturday so if I could get some help in verifying what I do actually need and create a proper list I'd be hugely appreciative.

[Oakman]

So I picked up the M50 and an E36 manual driveshaft on the weekend, also found an M50 flywheel and nearly new clutch for $10.

My question still is, will the M50 flywheel and clutch fit with my Getrag 240 transmission? I realize it's heavy and that most people use the M20 flywheel and starter, but I already have these parts.

Any help here would be appreciated.

[brian90]

to my understanding correct me if I'm wrong but you can use the 240 but you might want to change out your diff. You might not like the high rmps on the highway. For the drive shaft you need one out of a e36 because the position of the engine is going to move due to the new mounting places. People say on here that the 240 is a close ratio for a e36 . the whole flywheel thing and clutch and starter is the m42 clutch will burn up fast due to the m50 and the e36 is a dual mass flywheel so its really heavy. the starter from a m42 wont have enough power to turn the m50. sorry if any of this is off i have been trying to read up for my swap.

[Oakman]

Yeah, I want to get a 3.37 LSD, hence why I'm trying to save money other places for the time being. The 318is driveshaft is 5.2cm shorter than the E36 325i, so I'm assuming the transmission is that much farther back. Don't quite understand how the same mounts can be used with it that much further back but I haven't really looked at how the mounts work, they may move to accommdate that.

As far as the flywheel, that's what I seem to be finding, that it is possible but everyone runs the M20 to have less rotating mass. Call me cheap but to buy a different flywheel, clutch, starter and tob is money I'd rather spend on a different diff, which will make a much larger difference to every day driving than a lighter flywheel.

[xwill112x]

4.10 gears are fun with a m50. just bite the bullet and buy a single mass m20 flywheel, clutch, starter, pressure plate, and euro 323 tob.

[brian90]

I haven't looked it up so sorry for a dumb question but why a euro 323tob? (size,material,etc.) what's the advantage? Where the transmission mounts it is on like two rails that you can change the location of it. Cool but simple design.

[xwill112x]

you need that to convert to a single mass m20 setup for a dual mass m42 setup.

[brian90]

okay sweet i am going to start collecting stuff for my swap going to do it when i get money

[ethrty]

4.10 gears are fun with a m50. just bite the bullet and buy a single mass m20 flywheel, clutch, starter, pressure plate, and euro 323 tob.

maybe if you weld the diff. youd never get the power down with an open diff. OP follow the above game plan. if you cant afford this sort of thing then you cant afford do do this swap. you WILL have stuffups/errors hat cost money to be corrected. take your proposed budget and double it and thats what youll end up spending. have 1 or 2k (after buying engine/gearbox) in the bank to be on the safe side imo

[Oakman]

maybe if you weld the diff. youd never get the power down with an open diff. OP follow the above game plan. if you cant afford this sort of thing then you cant afford do do this swap. you WILL have stuffups/errors hat cost money to be corrected. take your proposed budget and double it and thats what youll end up spending. have 1 or 2k (after buying engine/gearbox) in the bank to be on the safe side imo

I'm sorry but I don't follow that thinking, just because I don't want to spend extra money for a performance upgrade opinion in a daily driver, I can't afford the swap? I've driven/owned a few cars with the M50 in it and I have no problem with the way it is stock, it's not like I'm doing any competitive driving with it where a lighter flywheel would give me an edge. As I mentioned I'd rather spend the money on a diff or suspension, because those are the upgrades that are important to me.

I have to say it's a little frustrating when the opinion of what should be upgraded is stated as fact, and there is no mention of other options. This is exactly why I wanted to ask this question, in all the faq's, guides, and I believe the wiki, they say that the M20 flywheel should be used but never why. IMO, I'd like to see that changed to mention that the getrag 240 (and/or whatever other transmissions work) can be used with the stock M50 flywheel and clutch and that the M20 parts are a great upgrade to do while the engine is out. Not all of us are going from M20's that have the majority of the parts needed, just an idea.

At the worst this post should come up if/when people search for this same question in the future.

[ethrty]

M20 flywheels is used for for not other reason than the M50 one is not compatable with the 240 box, and the M42 one needs to be ground down so much to work (needs the back side ground down to the ring gear) that its not safe to use. Meanwhile the M20 one needs a small amount shaved off the back and you are laughing all the way to the bank. thats why people use it. The fact it just so happens to be lighter than the M50 and M42 is a bonus

[Oakman]

You're saying the M50 flywheel does NOT work with the 240 gearbox?

[ethrty]

as far as i know no, but i think that is due to the fact you would need to use the M50 starter which doesnt work with the G240, rather than the reason of the flywheel/gearbox itself.

[Oakman]

Is there someone that can verify whether the starter is the issue for this combination?

I've tried searching and can't find anything about the M50 starter not working with the Getrag 240.

[xwill112x]

for real. just bite the bullet and get the m20 setup. your going to regret doing a halfassed 28lb flywheel setup.