The comprehensive DOHC engine swap thread.

[gills]

Amazing thread!!

Hey everyone,

Just want to say that this thread is extremely comprehensive and informative. I'm very glad that i read almost all of it. Thanks to everyone who has went through the blood, sweat, anger of performing these swaps because they truely are such an awesome project! Which is why i am here because i'm salivating at the mouth to do this project. Let me give you some history.

I basically have the bait dangling right in front of my face to perform an E30 M52 swap from a 96 328i and i'm going to go through with it.

My brother and i swapped in a '98 E36 M3 front clip onto his(everything; engine, tranny, brakes, steering..etc.. except body panels) '96 318ti about 3 years ago. Such a sweet car. Unfortunately at our last track day at Limerock park, CT he spun the ///Mti into the tirewall coming out of turn 1. Fortunately, all the mechanicals are in perfect shape.

What does this mean? well, he's already purchased a transplantee; a 96 328i. If i were to buy an '88 E30(which is going to be done within the next week) he will give(yes, give!) me all the parts taken out of his 328 to perform the swap at my disposal. He also has many extra parts from his 318ti as well but that's a whole other story. So basically i have a plethora of good stuff at my fingertips at no cost which brings me here.

My biggest concern is converting the M52 to OBD1. It seems there's a lot of little things and parts that are involved that seem difficult to source out. Although, from what i'm reading it is well worth the cost and work for the power gain. I've already read this link: http://homepage.mac.com/aceves/OBDI/OBD_ONE3.htm

Now is it 100% necessary to convert or could i just bring everything over from the 328 M52 to the E30 in OBD2 form? Or would that just be a waste? Or am i smoking something special?:pimp:

According to that link it says it is possible to modify the OBD2 harness for OBD1 but they don't go over it. Is it just easier to source out a pre 96 harness? Are there companies that sell complete OBD1 conversion packages?

Next is that i will also be using the 328 tranny. I'm understanding that i would need an E30 M3 driveshaft from reading here on r3v but http://www.theeurodepot.com/e30m50.html just says E30 driveshaft. Is that the only modification needed to be done to bolt the ZF tranny in or is there fabricating involved with the tranny mounts?

Would i be able to use the steering rack off of the 328? Is it possible to transfer the front hubs for a 5 lug conversion and the rears off the 318ti?

On top of those things other parts that i would need that i don't have:
E28 535 engine mounts
E34 525i M50 oil pan
E34 525i oil sump
E34 525i oil dipstick and tube
And if i need to go OBD1: 93-95 DME (color? i guess it doesn't matter anymore?), harness, M50 manifold and a whole bunch of other various sensors and parts...
I can't remember anything else right now, shit!
Any help would be excellent.

I would also eventually like to have A/C on the car and this seems to be something almost non-existent in most swaps that i've seen. I'm assuming because custom lines are needed to be fabricated. I do remember reading something about using E30 318is lines mated with the M52 or 20? I will have some extra A/C stuff from the 318ti and the 328i as well. The Ti has a mix of Ti and E36 M3 A/C lines if i'm not mistaken.

As far as wiring, i will worry about that once i have started.

Thanks in advance for any help,
Tom

[erik325i]

Would i be able to use the steering rack off of the 328?

Yes, you can use the e36 steering rack.

And if i need to go OBD1: 93-95 DME (color? i guess it doesn't matter anymore?).

As far as I know, you can use:
413 red label
413 silver label (requires EWS disabling chip)
506

I would also eventually like to have A/C on the car and this seems to be something almost non-existent in most swaps that i've seen. I'm assuming because custom lines are needed to be fabricated. I do remember reading something about using E30 318is lines mated with the M52 or 20? I will have some extra A/C stuff from the 318ti and the 328i as well. The Ti has a mix of Ti and E36 M3 A/C lines if i'm not mistaken.

It is possable to have AC. I think you need to get some custom lines though. If you have Zionsville's "Project Orca" CD, they explain what is needed to install AC.

-Erik

[gills]

Oh, i forgot one thing that i need as well, the 320i brake booster modified. One of the E30s that i will possibly be buying has an upgraded brake MC. He installed a E38 525i MC. I'm assuming there wouldn't be a problem since i bolted right up?

Good to know that the steering rack will work.

In the meantime i emailed a couple of places about OBD1 conversion packages and got a quote from one of about $650 but they were including the valve cover with that which i was under the impression is not needed? I told them to email me a complete list what they are including with the package.

I did find that zionsville A/C cd but for some reason i'm not a big fan of only giving information out for monetary purposes just to satisfy there thirst for greed. But if worse comes to worse that will be my last resort.

If anyone else can throw their $.02 in i'd appreciate it.

Thanks,
Tom

[Q is pluged in D]

Im doing a m50 engine swap soon. I was wondering if anyone knew if the multi-throttle intake body that BMP design sells and the Active Autowerks Twin screw supercharger would fit onto the m50. Im getting a 1996 m50. And whats advantages would having a multi throttle intake body and twin screw supercharger give me compared to a big bore throttle body and the twin screw supercharger? Im a noob here so dont bash me

kyle

[permit]

From what I can see (and assume), it looks like the SC would ram right into the brake booster (we're talking about the AA SC that replaces the entire intake manifold, right?)

Gills, the M52 valve cover is fine, you can use it. You just need to cut away slots on the side for the coil wires to pass through so the cover can sit flush.

[permit]

Oh, and I have A/C with my 24v motor. I just took it to an A/C shop and told them what to do and they did it. Cost a good amount though.

[Brew]

Im doing a m50 engine swap soon. I was wondering if anyone knew if the multi-throttle intake body that BMP design sells and the Active Autowerks Twin screw supercharger would fit onto the m50. Im getting a 1996 m50. And whats advantages would having a multi throttle intake body and twin screw supercharger give me compared to a big bore throttle body and the twin screw supercharger? Im a noob here so dont bash me

kyle

AFAIK, the twin screw will not work with a multi throttle setup. As Permit said, you might run into clearance issues with the brake booster. I say, if you have the means, buy AA's or Eurosport's kit and use a remote booster setup if you have to.

And your 1996 M52 is OBD2, keep that in mind.

[Q is pluged in D]

Are the performance parts for the M50 engine the same as parts for the M52, S50, and S52 engines. What I mean is would a cylinder head for example for M50 fit on a M52. Does that make sense.

[permit]

Not sure if this is right, but I think all the M5x/S5x motors had the same head, and it was just the block that was different (the cams were different too).

The general rule is to use S50 cams for an M50, and S52 cams for an M52. I think that is mainly due to companies not having a chip for an M50 motor with S52 cams, because it isn't a normal mod.

[Court M3]

has anyone know of a source of prefabricated mounts needed to use the e30 tranny with the M50?

[Addissimo]

I've heard that Tree House may make them, but i havent actually called to find out.

After I realized what a PITA (delicious, i know) it was going to be to get the group buy going for a custom brace, I was going to make some aluminum mounts. That'd be easy as hell. If you cant find them, go to the junk yard, get some big blocks of aluminum. start measuring, then start sawing. Tap some holes, sink some bolts, and you're set.

[m3needer]

hey new to the thread but i always used to browse anyway can some one post the exact wiring connections i need to make to my 89 m3 to s50
i know some like( green to green) and thats really it PLEASE HELP

[Drew325is]

Sorted...PDF is here:

http://www.amiles.com.au/Twin_Cam_Swap_FAQs_V0305.pdf

[deansbimmer]

Ok I've been lurking here for a year and made a couple of posts, but I'm ready to jump in here. I'm currently in the early stages of my swap. I've got two e30's an IS and an E, and some M50 parts. I'm holding off on the engine itself because I keep thinking I can find the right deal on an S50. ($1500 would be perfect- cheap I know) However, an M50 will probably be the end result. So after soaking up all this information, I have a couple specific questions (perhaps addressed at one point in time already).

-Does the S50 ECU have any advantages over the ECU for the M50? (or are they the same)? The computers seem to be an area of confusion for me, but at this point I know I dont want a silver label.

-Lightweight flywheel for the m/s50: It seems to me that the best bang for the buck is getting an M20 unit and shaving it down. Am I correct or is there a better way? (I'm using the Getrag 260 and stock sachs clutch)

-S52 cams into an M50: Good idea or no? I heard hardly anyone programs chips for these?

-Would I see a Decent power gain by putting a complete S50 head onto an M50? (or is this not possible without other modifications)?

Thats enough for now. Thanks everyone for their valuable input into this subject.

[Jarvis]

First of all, thank you for actually reading all of this and THEN asking specific questions. Very few people take the time to research all of this correctly on their own.

-Lightweight flywheel for the m/s50: It seems to me that the best bang for the buck is getting an M20 unit and shaving it down. Am I correct or is there a better way? (I'm using the Getrag 260 and stock sachs clutch)

-S52 cams into an M50: Good idea or no? I heard hardly anyone programs chips for these?

-Would I see a Decent power gain by putting a complete S50 head onto an M50? (or is this not possible without other modifications)?

Thats enough for now. Thanks everyone for their valuable input into this subject.

Yes, since you have a 325i you can use the single mass flywheel from that with the Getrag 260 behind the M/S50. A good machine shop should be able to take the stock flywheel down to about 13lbs, for less than $100 in labor. If you're on a budget and think paying $450 for a brand new lightweight flywheel to put behind a $500 used motor is ridiculous, then I'd recommend this as your best option. An M50 with just a lightened M20 flywheel will still rev pretty quickly.

I am not 100% positive, but I have always been under the impression that M/S50 and M/S52 camshafts are not interchangeable. S50 to M50 Yes, but as far as I know, S52 to M50 No.

If you're keeping the stock 2.5L displacement/bottom end and just adding an S50 head, you'll see the biggest gains up top mainly. [This should not be considered an average/easily attainable goal, but] one guy on bimmerforums made 212whp on a 2.5L M50 with S50 cams and good tuning.

You seem to really want more power than a stock M50 can provide. I suggest waiting longer and trying to find an entire S50 to start off with. In the end you'll have less headaches by just plopping in a stock engine instead of building some sort of hybrid motor. Good luck with your swap, whatever you decide on.