M42 into my E21, some engine questions.

[Damatheus]

Hey everyone,

I am getting ready to  put an M42 out of a 1996 318i into my 1977 E21 320i. The engine swap is a fairly straight forward swap, but it is almost always done with the M42 out of an E30 due to simplicity.

A have a few questions:

1) Putting the later M42 into the E21 causes oil pan clearance issues, but I've been told putting the oil pan from a 91 M42 onto a 96 M42 is a direct swap. Is this true? If it is, what are all the pieces that need swapping.

2) I plan on running a supercharger on the engine and want to make close to 300hp if possible. What size exhaust is best for this setup? I was thinking 2.5" pipe should be enough?

That's it for now, thanks!

[Damatheus]

Nothing? I figured these would be simple questions.

Or am I getting ignored for not using the search function 

[cadence]

yes e30 and e36 oil pans are interchangable. 2.5" would probably be minimum piping size.

[DesktopDave]

The E30 pan should be a direct swap, but it's a two-piece design.  Be sure you loctite the bolts in the upper pan - especially the front ones near the chain case - they have a tendency to loosen up over time.  Since those bolts secure the pan gasket for the oil pickup passage, the engine starves for oil.

I've never seen an E30 that didn't have a few bolt stampings in the lower pan... 

Don't know how much flow you'd get off a supercharger, never done anything like that myself.

[Damatheus]

Alright, those are perfect answers!

I will order the oil pan right away.

I will run 2.5" pipe for now, and if it ends up not being enough I'll just replace it with a bigger size.

Thanks!

[romkasponka]

You will need some other parts also, like oil pickup pipe and oil level dipstick. check realoem.com to be sure that you have everything you need.

[Damatheus]

pickup pipe and dipstick, got it, thanks again.

Looking forward to getting this engine into my E21.

[jolle21]

That's awesome man. Good to hear you're doing this swap. I'm doing an e30 M42 swap into my 1980 e21. Freshening up the M42 before I throw her in.



Curious...since your using an e36 M42, what driveshaft will you be using for the swap?

[colin86325]

Are those Kellners wheels on the E21?

[Damatheus]

That's awesome man. Good to hear you're doing this swap. I'm doing an e30 M42 swap into my 1980 e21. Freshening up the M42 before I throw her in.



Curious...since your using an e36 M42, what driveshaft will you be using for the swap?

The driveshaft question is one I need to bring up to the E21 guys at Bimmerforums. (I am over there as Damatheus as well) I have the E36 driveshaft and transmission, but I'm not sure those will work. It may just need to be shortened which would be nice.

I think I am the first person on the boards to attempt the E36 M42 into the E21, because the E30 M42 is so much more simple. But, I always did like to be different!