S54 Block Question

Is the S54 block the same block as a M54 just with different guts??

Not even close. To start the M54 block is aluminum, the S54 block is cast iron.

Tim

Besides material, is the stamping differnet?

I believe so. The bores are different (M54 - 84mm, S54- 87mm) and I remember reading that the S54 oil pump will not bolt up to an M54 so that part of the block is different as well.

Tim

ok let me explain alittle of what I am debating on doing. I want to put a s54 into a xi. I am curious if the xi oil pan will bolt up to the s54. Since I have never seen a s54 or taking one apart I am hoping someone else has. Plus is there anything on the bottom end of these motors that would hinder the passage way for the drive shaft?

Oil pan and transmission will bolt to the S54 block so you're good there. Question is will the crank clear the xi oil pan as the front driver shaft goes through the oil pan. You'll have to re-do the oil pump pickups but that is minor in the scope of this project. The big other problem is going to be electronics. You'll need to merge the M3 electronics with the xi harness and hope the DSC doesn't freak out with all 4 wheels powered. I guess if that does happen you could just have your ECU flashed to removed the DSC. I know Bimmerworld can do that for you.

These threads should help -

http://forum.e46fanatics.com/showthr...ht=s54+xi+swap
http://forum.e46fanatics.com/showthr...ht=s54+xi+swap