M50 swap, who’s doing or did one?

General conversations about BMW E28s and the people who own them.
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

M50 swap, who’s doing or did one?

Post by stubble88 »

For some reason I bought some else’s abandoned project. Maybe because it was and original red paint 535is. I’m weak for red 5’s.
Anyway. It has the classic daily mounts kit already and I have a redline harness on its way.
M50b25 getrag trans.
I’m in SoCal.
I’m just wondering if anyone here has done one or is in the process. If found some info but it’s hard to get specifics like AC, adapting all the hoses and smog equipment etc..
if anyone knows of good detailed sources of info or any help of any kind with these specific issues, I’ll take anything. That would be great. Image
jc72
Posts: 710
Joined: Aug 16, 2010 11:52 AM
Location: Oakland, CA

Re: M50 swap, who’s doing or did one?

Post by jc72 »

IMO its not worth the effort to swap a m30 for a m50. Maybe if it was an m20 car....
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Well that wasn’t really my question but thanks for your input.
jc72
Posts: 710
Joined: Aug 16, 2010 11:52 AM
Location: Oakland, CA

Re: M50 swap, who’s doing or did one?

Post by jc72 »

stubble88 wrote: Sep 08, 2022 9:04 PM Well that wasn’t really my question but thanks for your input.
I meant not many people have done it because it’s a marginal improvement over the m30 so there isn’t that much info about it here. It’s very popular with the e30 crowd though. You’ll find a lot more info on r3vlimited.com
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: M50 swap, who’s doing or did one?

Post by Mike W. »

As not even all E28 M30s used the same parts, I doubt there will be much info out there on stuff like A/C and P/S. You may be using M50 as generic for M5X, but like the others, I would not go M50. At least M52, if not M52TU or preferably M54B30. Same basic platform, but all different.

Smog. I've done a swap, got it thru BAR, but it wasn't as sophisticated then as now. I did have every thing done perfectly, it went smoothly and I even got a kudos from the referee. But for a M5x you will probably need M5x cats too, along with functioning OBD etc. Call them, they were pretty straightforward from my experience. I would describe them as tight, but not chickenshit. There is a difference.
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

jc72 wrote: Sep 09, 2022 1:05 AM
stubble88 wrote: Sep 08, 2022 9:04 PM Well that wasn’t really my question but thanks for your input.
I meant not many people have done it because it’s a marginal improvement over the m30 so there isn’t that much info about it here. It’s very popular with the e30 crowd though. You’ll find a lot more info on r3vlimited.com

Ah. Gotcha. Yeah the car just came like this already so I’m thinking of just continuing. But I’m also contemplating an m30 back into it. But then Ide have to find one. Thanks
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Mike W. wrote: Sep 09, 2022 2:44 AM As not even all E28 M30s used the same parts, I doubt there will be much info out there on stuff like A/C and P/S. You may be using M50 as generic for M5X, but like the others, I would not go M50. At least M52, if not M52TU or preferably M54B30. Same basic platform, but all different.

Smog. I've done a swap, got it thru BAR, but it wasn't as sophisticated then as now. I did have every thing done perfectly, it went smoothly and I even got a kudos from the referee. But for a M5x you will probably need M5x cats too, along with functioning OBD etc. Call them, they were pretty straightforward from my experience. I would describe them as tight, but not chickenshit. There is a difference.
Here’s on question of many:

What did you do so that the e28 temp gauge would work?
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: M50 swap, who’s doing or did one?

Post by Mike W. »

I've done a swap, but didn't mean to imply an M5x swap. Actually the temp gauge should be easy, I wouldn't be surprised if the E28 sending unit screwed into the M5x. If it doesn't, there are numbers on the side which relate to the range of it and you would need to match them. The late sending unit may very well have the right output.
Panici
Posts: 217
Joined: Aug 07, 2014 2:04 AM
Location: Canada

Re: M50 swap, who’s doing or did one?

Post by Panici »

Maybe I can be of some help with specific questions.
I've installed a 1996 M52B28 into my 1987 E30 325is.

Not the same as an E28, but similarities in terms of wiring and components.

Can't help with your A/C or smog questions, as I don't have any of that.
Although I did keep the EVAP purge valve in place and control it with my standalone ECU to vent the gas tank through the charcoal canister.
stubble88 wrote: Sep 09, 2022 9:34 AMWhat did you do so that the e28 temp gauge would work?
It's common in the E30 crowd to re-thread the "brown" cluster temperature sensor and install it in the side of the head.
I added a little thread sealant to mine and it has been working perfectly.

They even make re-threaded sensors in the aftermarket if you don't want to do it yourself.
https://racegerman.com/products/rethrea ... 0-24v-swap

Quick check of RealOEM shows the same part number for the E28 temperature sensor, so this may be what you need.


Picture of my E30:
Image
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

I'm finishing up a m50 + the zf 5 speed swap into an auto 528e - I have stuff to do but the punch list is pretty small. It pulls now which is nice
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Thanks everyone.

I also want the radiator with the side hanging reservoir. But that looks like the 318i or 4cyl radiator. Is that right? Can I use that one?

@panici What exact radiator do you have?
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

I have the radiator with the built in tank, I used one from a z3 1.9
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Galahad wrote: Sep 10, 2022 10:22 AM I have the radiator with the built in tank, I used one from a z3 1.9
Perfect. I’ll prolly get the behr
Thanks
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

stubble88 wrote: Sep 10, 2022 1:27 PM
Galahad wrote: Sep 10, 2022 10:22 AM I have the radiator with the built in tank, I used one from a z3 1.9
Perfect. I’ll prolly get the behr
Thanks
I have the Behr, bought it from FCP.

Installation notes:
I would have used a e34 525i m50 radiator bc that has the tank too, but it's too wide to fit between the frame rails. The z3 1.9 rad fits.
It's a tight squeeze to fit the fan depending on which engine arms you have, I ended up going electric.
I bought two of CEL-60859 from Summit and cut them to length, the stock radiator hoses don't fit.
I'm lazy and just used zip ties to hold it in place, there's probably better options but it doesn't line up with the stock mounts.
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

So you don’t have a clutch fan?
I am able to fit the e28 rad and clutch fan. I have the classic daily mounts. But I don’t want to run a separate tank.

You know what I would love? Some pictures of your engine bay. If you can.
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

Correct, I don't have a clutch fan.
I've got the classic daily mounts as well, they work pretty well but I had to install the driver's side arm after the engine was in the bay to get the mount to line up with the subframe hole.

ImageM50 swap by Holy Grail Labs, on Flickr

ImageM50 swap by Holy Grail Labs, on Flickr
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: M50 swap, who’s doing or did one?

Post by Mike W. »

Image

Color me skeptical. You no doubt have noticed that the radiator pictured is significantly smaller than stock or M50. Will it provide adequate cooling capacity?

Having been playing with BMWs many years now and remembering what the early cooling systems were like, the last thing I'd want to do is put in a smaller radiator. :dunno:
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Awesome. Thanks

Did a leak down test on the m50 if your interested. I did three rounds. Motor was cold. I added a little oil to the pistons.
@100 psi

1-100%
2-99%
3-100%
4-93% ?
5-80%
6-100%

4 was 93% the first test but then couldn’t get it past 33%. Guessing the exhaust valves are sticking open. Probably normal for a motor that has bee sitting.
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

Mike W. wrote: Sep 11, 2022 7:52 PM ...

Color me skeptical. You no doubt have noticed that the radiator pictured is significantly smaller than stock or M50. Will it provide adequate cooling capacity?

Having been playing with BMWs many years now and remembering what the early cooling systems were like, the last thing I'd want to do is put in a smaller radiator. :dunno:
I did think of this issue when I started - short answer is I have no idea if this radiator is big enough. I installed a high flow water pump pulley and I'm working on an electric fan controller with better temperature readouts than the iffy temp needle. I haven't driven the car enough to really heat soak it.
Either way I'm going to find out!
Panici
Posts: 217
Joined: Aug 07, 2014 2:04 AM
Location: Canada

Re: M50 swap, who’s doing or did one?

Post by Panici »

stubble88 wrote: Sep 10, 2022 9:09 AM @panici What exact radiator do you have?
M42 Radiator (Mahle 376713121)
SPAL Electric Radiator Fan (16" Pusher - 30100401) controlled by standalone ECU.
No clutch fan.
No A/C condenser.


No cooling issues running the smaller rad in 2020 with the engine naturally aspirated. Was using the original thermostat, plastic housing, and unknown mileage water pump at that point in time.

Note that I do have three separate coolant sensors to keep track of things. OEM cluster sensor (rethreaded), VDO water temp gauge, and standalone ECU temperature sensor (reused the M52 sensor).
Also programmed the ECU to light up the "check engine" bulb on the dash if the coolant gets too hot.

I've since switched to an Febi 176F/80C thermostat with an aluminum housing. I've also installed a new OEM water pump.
No issues thus far while turbocharged this past month, although it does run the electric SPAL fan more often with the reduced cooling through the massive front mount intercooler.

Note that I've only street driven the car with this radiator, the true test will be at the track running open lapping.


Image
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Your car is insanely amazing. :shock:

What is the wire harness holder/container against the firewall called? where can one get that?
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

You're talking about the box with the clear blue cover in Panici's car? That's the fuse box (in what I believe is the stock location for e30s).
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

No
The black long box that holds the main harness up against the firewall. Above the rear of motor.

Sorry. I explained that poorly the first time.
stubble88
Posts: 76
Joined: Aug 08, 2022 8:40 AM
Location: Agua Dulce SoCal

Re: M50 swap, who’s doing or did one?

Post by stubble88 »

Image
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: M50 swap, who’s doing or did one?

Post by Galahad »

stubble88 wrote: Sep 14, 2022 9:11 PM No
The black long box that holds the main harness up against the firewall. Above the rear of motor.

Sorry. I explained that poorly the first time.
Ooooh that thing.
The black wire box doesn't have a name that I know of, it's built into the stock harness for e34 m50 cars. I don't know if e36 harnesses have the same thing, they have the ECU in a different spot so possibly not. I'm actually trying to figure out how to take it off, it doesn't fit between the intake manifold and the firewall and is rubbing against the hood liner a bit. I may end up doing a custom tucked harness to clean things up a bit and get better fitment, the ECU plug doesn't have much slack to play with behind the glove box and there isn't another place to stick the ECU that I'm happy with.
Post Reply