The comprehensive DOHC engine swap thread.

[focoe28]

reading this thread is pretty inspirational for anyone wanting to do a m5x/s5x swap into an e30.

[Thujalvi]

I've been trying to find out if the oil pan from an m51 fits into the m52 without causing trouble. A quick look around didn't yield anything, so any info on the matter is much appreciated. At least in this corner of the world, the diesel's pan is a fair bit cheaper.

[NotColtonOrr]

Didn't think this was worth a separate thread so figured I'd ask here.

Im starting out with basically a bare m52 (no ECU, wiring harness, accessories, nothing). Since I'm going to have to source all these parts, Which would be more cost efficient. OBD1 or OBD2?

[ZekeTheSneak]

probably obd1 but alot of people just throw out there obd2 stuff so you could score it for free ya see? I bought a m50 vanos complete with every sensor harness and ecu for 500 from a e34, Then sold the block for 250 and kept the swap parts. Then I bought an s52

[MikeDE]

Looking at an M52B25 over here in Germany. It's out of an E36 323i. The original engine harness has been cutoff completely, but this doesn't concern me. What does concern me is EWS?? Since it's a later motor, will the DME/all DME's for this motor have EWS?? I understand that this motor/DME has a later operating system...true?

Sorry for the q's, but it's the first time I REALLY am serious about an M5x swap. I like the M42, but after only 14mos, i've grown tired of the noise.

[nokincy]

If given the option would you guys run m52 exhaust manifold or the ebay long headers? Both coupled to a custom exhaust from their respective end point back.

[etxxz]

long tube headers! Make sure you get GOOD exhaust flanges that won't leak or loosen with time.

Y to a single 3", flex coupler (welded) and put your muffler of choice all the way at the back. A good one, like a Borla Pro XS.. a $200 muffler that'll sound like Gods are fighting inside. Overall cheap and light. This was my setup, none sounded better, years of track.

[bimmer630]

I thought about a flex coupler.. But forgot to order one. The stock E30 system didnt use one so shouldnt it be ok without one? Im Using a long tube header, y pipe to 2-1/2", full stainless piping, to magnaflow muffler and PYPES twin outlet stainless tip. should be nice

[JRKOUPE]

I thought about a flex coupler.. But forgot to order one. The stock E30 system didnt use one so shouldnt it be ok without one? Im Using a long tube header, y pipe to 2-1/2", full stainless piping, to magnaflow muffler and PYPES twin outlet stainless tip. should be nice

the stock system was engineered to fit rather well...no flex coupler needed to allow for fit /vibration issues..

you may not need one if your system fits well......

I live in NY..who is doing your fab./install?>..... you can e me or pm if u wish.......thanks


Ive used KOOKS on LI....one of the best...but they are now in NC.

thnx!

[etxxz]

yeah that should be nice. are you sticking with 2.5" piping then? 3" is what you want, but i found it hard to fit in my s52 swap so stuck with 2.5". I regretted doing that. Area wise 2x2" = 6.3in2, 2.5" = 4.9in2, but 3" has an area of 7in2. No brainer.

Anyways, a flex coupler the closer it is to the engine it will get rid of raspyness, that is my experience. I never do a system without one. Same thing with the Y or Xs, the closer to the engine, the smoother things turn out.

[bimmer630]

Ive read through the forum here and most guys say a 3" is far too large for a stock S50.. 2.5 should be fine regardless.

Im doing the work myself.
I work here http://bhautosport.com/
The website is still a work in progress

Our MAC tools guy was just telling us hes good friends with the guy who worked at Kooks. I guess they moved down south and a bunch of guys from there stayed on LI and started a new Exhaust shop (??)

[nokincy]

I'm using an m20 single mass flywheel and clutch on my m52 with a g240. Will I need to use the m20 throwout bearing or get the euro 323i throwout bearing?

[drummerchubbs]

I'm sure this is covered, but I've searched for a long time with no definitive answer. I have a m50nv that used to be an auto. Im swapping into a 318i with a zf320.
1)Does auto have a flywheel?
2)What is the preferred DD (some drift sessions too) flywheel and clutch set-up. Thanks

[nokincy]

I'm sure this is covered, but I've searched for a long time with no definitive answer. I have a m50nv that used to be an auto. Im swapping into a 318i with a zf320.
1)Does auto have a flywheel?
2)What is the preferred DD (some drift sessions too) flywheel and clutch set-up. Thanks

1. No.
2. M20 or e36 m3

[drummerchubbs]

Thanks nokincy