The comprehensive DOHC engine swap thread.

[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?

[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 (??)

[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.

[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!

[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

[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.

[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.

[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.

[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

[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?

[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.

[focoe28]

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

[rightcoastbias]

M42 318is radiator
+ 14" pusher fan
+ Dayco 71901 (This hose can be cut in the center and trimmed to provide both upper and lower radiator hoses)
+ 80deg tstat (I drilled a 1/8 inch hole at 12' o'clock)
M52B28 block + M50B25 Head + M50B25 413 Red label ECU
eBay knock off supersprint longtube headers
M52B28 Dual Mass Flywheel (the suck.)
M42 G240, stock Throw Out Bearing, stock slave cylinder
E36 M50 manual drive shaft + E30 CSB mounted backwards
E36 M50 manual shift linkage and bracket
Small Case S4.10
Slotted factory E30 brake booster 1/2" + modified brake pedal
One stupid grin.

[amcink]

This thread is a great idea Ryan. It seems more and more people are becoming serious with the DOHC(M50/S50) engine swaps rather than just throwing a whim of a dream they had onto the forums. This is some very helpfull info that I saved a few months ago from Chuck Waits. Hope this can help.

E30 M50 ENGINE CONV PARTS LIST

"1. E30 88' radiator, I used the e36 unit with the lower mounts raised
2. E30 88' radiator over flow tank
3. E30 M20 fan, poss. w/clutch
4. E28 533i motor mounts w/ 5mm spacers or e28 m5 mounts with out spacers
5. E34 throttle cable
6. E21 brake booster w/ modified shaft, to 15mm or 325IX/e32 735 without mod to the shaft
7. E34 M5 or 25mm brake master cylinder w/ additional brake line used for the 325ix booster
or a e32 735i with the modified 320i booster
8. E30 325 trans X-member
9. E28 m5 or two 320i trans mounts/ which are cheaper
10. E30 M3 driveshaft or i used the front of the e36 mated to the rear of my e30 M3 have it rebalanced
11. E30 diff. w/ 3:25 ratio or E28 533i w/ 3:25 LSD
12. E30 318 ECU mount
13. E34 oil pan
14. E34 oil pickup
ect. ect.
15. E36 m3 exhaust manifold
16. M50 radiator hoses
17. E36 M3 Motronic
18. OBDI intake manifold
19. OBDI throttle body boot
20. E36 alloy mounting arms
21. OBDI wiring harness DO NOT BUY silver label ?413? motronic, it has EWS (security),
it can only put into original chassis
22. the engine harness and the ECU are all E36 M3.
On the standard E30 with M20 engine fitted, you have the large round plug (C101) up on the firewall next to the brake booster.
This plug has 2 parts. One half is connected to the car wiring, and the other is connected to the engine harness.
When the M20 was removed, the engine side of the plug was removed with the engine. Now I have the S50 half of the plug in its place. Although similar in appearance, it will not plug directly into the E30 half of the plug.
I removed the E36 engine half of the plug, and replaced it with an E30 one. This then allows the 2 parts to screw back together. All you need to make sure is that you have the correct wires connected to each other. Its not just pin 1 to pin 1 and pin 2 to pin 2 etc (although some of the wires do actually connect this way).
This plug connection is the only point where the E30 & E36 wiring interface with each other. The rest of the E36 M3 engine harness is totally self contained.

23. the exhaust from the downpipe to the muffler is all custom made

This is not a complete list but damn close if you need any additional info feel free to email or call me at
INTERNATIONAL AUTO
770-745-0501
my name is Chuck Waits, and we are open from 8 to 5pm EST"
________
Yamaha XV750

Is this list up to date? Since I just got a 1993 M50 (do not know it is a tu or nv) that will go into a 1985 and I want to gather the rest of the items.
Please, let me know

[MaxBell]

Yep, the 1 pin E30 (brown top) temp sensor uses the same E36 plug.

QUESTION: I read that there is a wire (Pin 2) that has to be hooked up from the C103 plug in the glovebox to prevent a 3500 rpm cut out.

Where do I wire this to? I have a 3500 rpm cut out.