Firstfives.org

Does anyone know what modifications might be needed for a M30 w/4spd to M10 w/5spd transplant?

Thank you very much for your help.

j[/b]

Am I reading this right? You're swapping out a big 6 and putting in a 4-cyl? What car is each drivetrain coming out of and going into?

Not judging, just wondering...

Thank you for your open mind.

Too late, I know you think I am mad.

The M30 is presently in a 1977 530i with 4spd manual. I would like to replace it with the lowest displacement M10 engine possible with an accompanying (hopefully) 5spd manual from, most likely, an E21 320i. They seem to be the most readily available in my area of Southern California.

Cheers,

j

You would probably need new motor mount brackets. I know that when e21 guys do m30 swaps, they need to make new mounts. You could just use euro 520i ones. You'll also need to work out a driveshaft solution. You could try an e21 driveshaft, but it may not fit without modification. Also, only the e21 5-speed has a mechanical speedo gear like the e12. Oh, and you might need a shifter assembly to fit the e12. The other things you'll need are intake and exhaust (which would be custom anyway for the turbo) and to rig-up the electrics to the e12 fusebox.

What exactly are you trying to accomplish? If you tell us your goals, we can probably help more. Sometimes it helps to "think aloud" over the interwebs.

Well, 1600's from the BMW 1600, the lower displacement brother of the 2002 is a smaller M10. 1500s existed, but finding one might be next to impossible. You should be able to legally smog it with a 1800 engine from a 320i, if you keep everything on it, including a cat. Any of the 320i 5 speeds will work, they all have mechanical speedos. A custom, longer driveshaft might be the most expensive part, though you might be able to mix and match from a E23 or something. It's going to be way overgeared with a stock diff, 3.64s aren't too terribly hard to find, but it really would need a 4.10 or so in the heavy US spec car.

I question where you're going with this, but to each his own.

I have a 3.91 rearend if you are interested.


Jeff
757-593-3478

You can use the engine support brackets and engine mounts from the euro 520i (the four cylinder one anyway). The gbox from the e21 will work but the guys are right, you'll need a custom tail shaft. The shifter will poke through in a slightly different spot, but you should be able to cut and make it fit.

The 520i came with a 3.91 diff but the original 518 came with a 4.44. I'd be super surprised if you found one. I don't think they made it to the US. The 3.91 was in the 2002, so there should be some around.

What are you doing for induction? If you go with carbies, you'll need to modify the fuel system.

There'll be some silly little things too. Your fan will be too far away from the radiator (the 4 cyliders have a special addition to push the radiator closer to the engine). The radiator hoses won't fit either. You might need to relocate the radiator overflow to because all the induction is on that side for the 4 cylinder.

I like you're thinking though. I'm assuming you're doing it for mpg reasons? You could go really crazy and get an M43 out of a 318ti. You'd need all the electronics though.

Cheers