M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: bflan2001 on May 12, 2010, 12:19:27 AM

Title: M42 into E21 swap advise needed
Post by: bflan2001 on May 12, 2010, 12:19:27 AM
I'm trying to figure out which year to get my engine & transmission from. I want to keep the wiring as simple as possible so I know I want a pre-96 donor car. What I can't figure out is which year (89-95) would be best for a swap. Looking for some advise there. I'll be doing an EDIS conversion at the same time if that makes any difference.
Title: M42 into E21 swap advise needed
Post by: bmwman91 on May 12, 2010, 04:27:35 PM
I would probably go with an E30 M42 (1990 or 1991 318i, 1991 318iS) since it has slightly simpler wiring. The E36 ones had the DISA intake manifold& knock sensors which are just more things to wire in. I haven't swapped an M42, so I cannot really give too many tips. I think that there are 2-3 guys here who have put them in E21's though.

You probably don't need to mess with the EDIS conversion. The M42 uses solid-state, coil-per-cylinder ignition.  There is no need to do an ignition conversion since it never had a distributor.
Title: M42 into E21 swap advise needed
Post by: DesktopDave on May 12, 2010, 08:18:55 PM
You're planning on a megasquirt?  Let me know how that turns out...I agree with bmwman91...he always gives great advice.

Definitely look for the e30 for the better intake manifold.  You could also buy an e36 motor and swap the manifold...they're on here all the time.  As for donors, keep an eye out for the 318i sedan too, like mine.  It was a one year budget special so it'll likely be cheaper...and it's mechanically identical to the iS...they all had five speeds too.