M42 to M20 Swap?

[bmwpower]

I know, I know, but I have all the M20 donor parts which I have a bunch of money into. Has anyone attempted this swap besides that guy from Europe (I searched here)?

[Lair]

I'm doing this also. Nobody has any advice for me.

[BrandC]

I'm sure the hardest part is going to be transferring the wiring, which isn't going to be that crazy if you have the donor car already.

The only advice I can give is just get your hands dirty. If ppl can swap M/S50/52's into E30's, you shouldn't have a problem transferring E30 to E30 engines.

[Hick]

I did m20 to m42. wiring is plug and play, one wire on the chassis side is a ground, where as the other is a power. look into it by finding a schematic showing what pin goes to what.

nothing hard about it, you need to remove and replace the air box and coolant tank brackets, but the rest is the same.

[bmwpower]

I did m20 to m42. wiring is plug and play, one wire on the chassis side is a ground, where as the other is a power. look into it by finding a schematic showing what pin goes to what.

nothing hard about it, you need to remove and replace the air box and coolant tank brackets, but the rest is the same.

He's talking about M42 to M20, which is potentially different.

[bmwpower]

I'm doing this also. Nobody has any advice for me.

Yea, don't say I didn't warn you....:)

[Lair]

I have a complete M20 harness and ECU. The wiring will be the easy part.

I'm more concerned about the driveshaft, shifter, & cooling than anything else.

[bimmer_adam69]

i dont mean to shite on your thread but why not post this thread in m20 or the m42 section....i know this is m30 and other swaps but.....its m20/m42talk:p

[Hick]

He's talking about M42 to M20, which is potentially different.

Yeah, i know.

If everything from my M42 car bolted into an M20 car wouldnt you think it would be the same thing if it were the other way around?

And advice is given: Check the pin orientation of the C101 plug and your golden, much like any other common swap discussed on this forum.

[EKramer]

Did you ever find out if you can use the m42 drive shaft with a m20? I am getting ready to do the swap.

How did it all work out for you?

[lukeADE335i]

have a look at the lengths on RealOEM. That will tell you.

[SmokeE30]

I pretty sure you need an m20 shaft but it depends on what trans your using anyway, but the swap is pretty much plug and play, we have replaced a couple dead m42s with m20s. C101 and everything works fine. theres only a couple minor differences in the engine bay like ground location and relay mounting location but if you've ever worked on an m20 car before its a simple swap just not much documentation out there because there's only a handful of m42 powered e30s and only a handful of them ever get an engine swap, and out of them only a handful get m20s.