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E30 Alternator on E21?
Posted: Mon Aug 31, 2026 4:23 pm
by ryanwnixon8
I have a bum alternator and would like to get a little more amperage than the 55 bosch reman.
I have seen some say that an E30 alternator will fit with the '84-'85 adjusting bracket and some tweaking. Does anyone know if this is true?
(I have a '78 320i and this is my first project car. If you think It'd be too much of a hassle and should just get an e21 alternator then let me know)
Re: E30 Alternator on E21?
Posted: Tue Sep 01, 2026 9:42 am
by Jeroen
Welcome here!
I've seen some different versions and fitments over the years, but it is most likely that the alternator from another M10 engined car will fit, especially if E28 or E30. Perhaps try the local scrapyard so you can compare before you buy, you can always have it overhauled later, or just fit it with a fresh set of brushes.
Feel free to share some more info on yourself and your car in the owner's gallery, and enjoy the forum!
Re: E30 Alternator on E21?
Posted: Tue Sep 01, 2026 2:55 pm
by nic65
Io ho usato quello della E30 da 90A ma ho sostituito il supporto sul motore perchè il fissaggio dell'alternatore è più grande
Re: E30 Alternator on E21?
Posted: Tue Sep 01, 2026 5:34 pm
by ryanwnixon8
Jeroen wrote: Tue Sep 01, 2026 9:42 am
Welcome here!
I've seen some different versions and fitments over the years, but it is most likely that the alternator from another M10 engined car will fit, especially if E28 or E30. Perhaps try the local scrapyard so you can compare before you buy, you can always have it overhauled later, or just fit it with a fresh set of brushes.
Feel free to share some more info on yourself and your car in the owner's gallery, and enjoy the forum!
Thanks, Joroen. I have been amazed at how responsive you are within the forum while I've been looking through it. You should be very proud of the community you have amassed.