The comprehensive DOHC engine swap thread.

[deansbimmer]

Thanks for the reply. I'd be happy to start off with around 200 whp. This will be a daily driver of sorts. I would certainly love to have an S50, but I dont think i will ever get myself to drop $3k+ on a used engine, so my wallet keeps talking me into the M50. Lets keep this thread going, anyone else still in the build process? I'm sure I'll have more questions later, but what about the M/S50 ECU differences and compatibility? Thanks again.

[Addissimo]

As far as the s50/s52 cams thing goes:

You can put s50 cams into an m50 with no problem

You can put s52 cams into an m52 with no problem

You can put s52 cams into an m50 with the s52 cam trays (stu may correct me, I know the schrick cams for the s50/s52 are the exact same thing, that makes me think you should be able to just swap them out, but if not- use the OBD-2 cam trays for the OBD-2 cams)

Ecu compatibility:

The 413 is used on the m50, I've heard of 413 ecus coming in 95 m3s, but haven't actually seen it to verify. The 506 silver label is the only 95 m3 specific ecu. If you try to use it with an m50, you'll fail emissions tests, and run very rich (ask how I know.)

If you're going to go for an m50 with cams- I say do exactly that, and get a chip from TMS. They have one for that specific setup costing around $250.

The main benefit of using an s50 head is you get the valve train. The head castings are exactly the same, but you get conical valve springs, lightweight retainers, and lightweight lifters in the s50 head- that all allows for a slightly higher redline (7200 rpm or so.)

I have a friend with a stock m52 (aside from the headgasket) running 14psi with an SDSEFI system who seems to think its okay to redline at 7600rpm. Hes been doing it for a long while now, but I wouldn't recommend it to anybody unless you have deep pockets.

If you're at all interested, I have a complete swap for sale including everything you need minus the transmission bracket.

Its an m52 with SDS standalone fuel management, the wiring harness is made up, and it includes a wideband o2 sensor for tuning. Its a pretty mean setup. The same friend mentioned above had this setup before he turbocharged, easily the fastest NA car i've ever ridden in- thats saying something.

I would be willing to just sell the swap kit minus the SDS if anybody is interested.

-Addis

[325Projectz]

Ecu compatibility:

The 413 is used on the m50, I've heard of 413 ecus coming in 95 m3s, but haven't actually seen it to verify. The 506 silver label is the only 95 m3 specific ecu.

My S50 came with a 413. They are very common with S50's. 506's are worth more money, m3 only, and no ews.

[raimo]

Has anyone put a M50/S50 engine to an iX ?

[325Projectz]

Has anyone put a M50/S50 engine to an iX ?

Rumor has it, some guy did it over in europe where they have e34ix m50's to get parts from. But then again, thats just what I heard.

Either way, if your in the states forget about it unless you have jesse james fabrication skills.

[raimo]

Rumor has it, some guy did it over in europe where they have e34ix m50's to get parts from. But then again, thats just what I heard.

Either way, if your in the states forget about it unless you have jesse james fabrication skills.

well, im not :) and 525ix parts can be found ;) im more intrested in how to fit the engines with tranny, rather than the problems with fwd. fdw with an m50/s50 is practically bolt-on job using the 525ix parts. i know that the iX blocks are different, so i guess some adapters should be used.
moreover, how would the stock Getrag 260/5 hold up with over 300hp ?

i could go and ask a guy who has an S54 in his iX bodyshell, but these are really busy guys and im only considering what engine to go with

[nando]

well, im not :) and 525ix parts can be found ;) im more intrested in how to fit the engines with tranny, rather than the problems with fwd. fdw with an m50/s50 is practically bolt-on job using the 525ix parts. i know that the iX blocks are different, so i guess some adapters should be used.
moreover, how would the stock Getrag 260/5 hold up with over 300hp ?

i could go and ask a guy who has an S54 in his iX bodyshell, but these are really busy guys and im only considering what engine to go with

it's been done, there are pics buried in E30.de. I believe he used the getrag 260 (bolts right up), and I see no reason why it couldn't handle the power of an S50. basically you need a customized oil pan, probably motor mounts, exhaust, etc.. I considered this option heavily, but personally I don't think it's worth it. It would be easier to build a stroker M20 or turbo the stock motor, and focus your custom R&D $$ on beefing up the ix drivetrain.

as far as 525ix parts, I don't think it would neccesarily be bolt on. you would for sure have to use the entire 525ix tranny/trasnfercase/front diff/oilpan/halfshafts (customized to mate to the ix front hubs), and have a custom gearset made for the front diff (they are not the same ratio and the ix diff will not work with the 525ix oilpan or driveshafts). plus a custom rear driveshaft to mate to the 525ix tranny, etc. etc. Any way you go at it you are looking at a lot of custom work and a lot of money.

[raimo]

well, i didnt think that everything would be bolt on. i though of a S50 because it seems the best bang for buck solution. a stroker output is somewhat limited beyond 200hp and going turbo means buying stuff that are worth the same as a S50 in good condition (last S50 for sale here was about ~4700$). 6 turbo pistons and an EMS would cost about half of that alone. but i more and more attracted to a M50 swap ...

EDIT: ok, i've read this tread from the beginning "a bit". seems that the getrag 260 tranny bolts right up to a M50 and i can use the same m20 flywheel and clutch (i also have a spare m20 flywheel and clutch if necessary). the wiring should be a problem, cause i know a mechanic who is specialised on bmw electrical systems.
but im a little confused about the engine mounts and that transmission bracket. i understand that the bracket can be self made ? (i have all the welding equipment etc). i also think that im going to make my own engine mounts, since it not so hard.
the thing im not sure in is if my diff ratios will suit. i have 3.64 diff which are the fastest for e30 iX's.

thanks for the input and greetings to other iX owners from a little place called Estonia

[echothreezero]

The 240 Getrag from the m10 is not able to be used for this swap. I however, have a 240 getrag currently on my 1989 320 6-cyl m20 that I took off a South African 320is pre f/l e30.

Can I safely assume that since the 'box bolts straight up to my m20 I can use it for my m50 swap? The 'box is obviously not the same as the one built for the m10.

[DanGillan]

alright, i just read that entire shit, good thread.

long story short, the reason im here is my m20 threw a connecting rod and blew a half dollar size hole in block at cylinder 1 last sunday. So im quickly going m50. I have a 92 non vanos complete motor from a 525i automatic wagon. new head 10k ago, 90k on motor, solid everything. m20 is ready to come out and the car goes to BPG where i worked before i went to school for some after hours shop time.

tomorrow the m20 comes out, and the car gets a ton of maintenance items like tie rods, power steering hoses, guibo, CSB, etc... and the motor gets items like water pump, tstat and housing, plugs, belt, oil change, etc...

im using my trans (getrag 260) my flywheel, new sachs e30 clutch kit and hopefully keeping my built 4.10lsd

i have e36 mount arms on order along with the proper mounts, i will make the trans bracket at the shop. I have a 320i booster on order, i will be waiting the longest for that. I have the e36 throttle cable and various coolant lines on order as well, i will more than likely be replacing many more coolant and vacum lines as i go.

So i basically have everything figured out, except I have a few questions.

1) The harness that came with the car is from an auto 525, so it will be too short and a few of the wires are dry rotted. So im thinking just getting an e36 harness and rewiring the engine with that harness, and doing all my wiring before i even put the harness on the engine. good idea or should i stick with the e34 harness and just fix the few rotted wires?

2) I have no DME. car is a non vanos from a 92' 525i. which DME can i run and can i run stock software for now or must I go aftermarket?

3) Once everything is done and motor is running, i will bring it to the exhaust shop for custom downpipes. I'm keeping my supersprint cat-back. I'm thinking about just telling them to run 2 or 2.5 inch piping from the manifolds, to 1 or 2 high flow cats, then attach to my cat back. will this be too loud? should i toss in a resonator? what have people done exhaust wise? how do you like your set up?

4) I hate to be a jackass and ask this kind of question again, but does anyone have an EXACT wiring diagram for a non vanos engine wiring harness to a late model e30 body plug?



The knowlege in this thread is unbelieveable, i think this is the only thread left on r3v that can teach me anything. good shit. thanks for any help and support. I hope to have this finished within two more weeks, and i have and will have plenty more pictures to document the process. thanks

-Dan

[kylebes1]

Good to see this swap is still alive.

First, find yourself a proper e36 harness. As you said the e34 is too short, and you don't want the bad wires...

I had a big chart with all the wire uses. The e30 side is easy... I will make a good chart and post it, asap.

[Low Level E30]

The E34 non-Vanos harness is too short?

So an E36 non-Vanos harness is absolutely required...?

[permit]

Uhhhhh, I've had, and have (again) an e34 harness in my car, and it gets through the firewall and into the glovebox just fine. The wires just become tight once you get them 1-2 inches into the glovebox.

You can run the stock non-vanos e34 DME. I believe the number you're looking for is 405.

[DanGillan]

i knew the e34 harness would work, but the rotted wires combined with the "too short" factor just makes it easier to buy another harness. car is heading to the shop in the next couple hours for a sunday on a lift. i cant wait. ill have pictures and hopefully a mini writeup done when i finish all this.

[bam2002]

New Twist E 21

Well since My 1st attempt to post blanked out the page.. And I dont feel like typing it all back in again.. here is the short version.

Has any one done a M 50 into a E21. I have a E30 also but thinking the E21 is ligher. And I happen to have a Rust free 320 IS laying around with 104K miles that is starting to but oil. Plus it has Strut/ spring and Sway bar upgrades.
I have seen a Aplina E21 with a Bug 3 3.5L stuffed in it. SO I am thinking a M50 will fit. But the M50 is a wider engine thant he Big 6.. Guess Ill have to go out and measure engine bays.

I also found some weights on the Web. The 4cyl is 180Lbs vs the M50 at 306lbs.
The only other concern would be the tranmission tunnel size.

Thoughts??

Barry