First ever M50B30 + 4L30E A4S310R into e30

[EduardoGomez]

How to make your M50tu better than S52 for less than $1000? Read on…
How many posts do we see people posting about their E30 project without even starting a project? I do see a lot, then you see the guy barely bought the swap engine two months later. I decided not to do that, and decided to document everything as I go along and then when I am done, I post. Sounds fair enough. And because I am doing something that hasn’t been done before, it is better to post a project thread once final results are here.
I am proud to say that I am the first person to do a M50(budget better than S50) with GM 4L30E swap into E30. I searched the internet and I could not find any information about a person that swapped 92-95 E36/E34 automatic 4 speed transmission into E30 chassis, some say that member Jahnaboi did it but I could not find any evidence of that. I did sent him a PM but he never responded so he probably never did this.
Reason why I went with this A/T swap is because Van Diesel in the brand new Fast And Furious movie Fast Five drives an automatic so I know automatics are better for speed. Yeah baby. You know when you see the movie you are like “yea automatics rule”. Power of Hollywood baby. Lol, I know some people will take this too seriously.
In reality automatic can be faster in ¼ mile, you can load the power off line and don’t worry about missing shifts. 4L30E GM transmission is nice responsive tranny with locking torq converter that came in the heavy SUV Isuzu Rodeo and well as super heavy E34 so I know they will handle light weight E30.




After owning my (march of 1991 production) 325i coupe A/t for 10 years , I can say that there is no car like it, I realy like how the car feels, much better than my 2002 330ci. I imagined that with better engine and transmission it would be even more fun, and man I can tell you I was not wrong. M5X/S5X swap is the way to go.



After searching to buy me a M50 engine will little money, I’ve found out that is cheaper to buy the whole donor car than to be buying parts seperatly. And best M50 donor would be 93-95 E34 because you don’t have to then look for oil pan, easier to get E36 mounting arms than E34 oil pan. I managed to find running 1995 525i with auto transmission for $700, it was wrecked in the front then the person try to fix the front end then end up just selling it. 220 000 miles on the odometer, but it does not matter, it all depends how was maintained. And E34 engines will show less abuse than for example M3 engine with 80k miles but redline miles.


I’ve found out later in the progress of the project that E34 is the way to go for donor car. Harness cover sits just perfectly on the E30 firewall. Intake boot bigger angle, better flow. A/T transmission selector sits at same spot as E30 and will bolt right on, and stock E30 shifting cover fits fine.

Removing everything from E34 was easy, just take off the radiator support and engine comes out easy.


Notice the area where A/T selector is and two holes in the front. To remove the A/T electrical harness, whole carpet needs to come out.

After the M50tu engine was taken apart I noticed that is indeed very good engine that did not see any abuse. Head gasket was in very good condition indicating that engine was not overheated.

Cylinder bores were in mint condition despite the very high mileage, again mileage is just for the resale blue book value it doesn’t mean much to me. A S50 with 50k miles shows more wear than my 220k mile core engine, lol.

I decided to build a stroker M50 engine and bought M54B30 short block from local BMW salvage yard(sport car recycler, Dwuane and Pike) that they thought is junk motor. I payed a maximum price of $500 in my opinion a rip-off, but what can you do all german car salvage yard people are bunch of arrogant sociopaths. I just bought it and they asked my why do I need it, and when I told them that this engine parts can be used in M50 engine to stroke it to 3.0L, the salvage yard guy quickly went to look if he has more.

When I brought the block to my house, I cleaned the block and checked it for warpage and wear, I found out that is a very good block with no damage what so ever. And later that I went to that same salvage yard, the guy(dwane) asked me what did I do with the block and I told him, I pulled the parts that I need and sold the block for $150, and he was not happy to hear that. A arrogant sociopath thought that he knew everything about BMWs but I showed him he is not a match for me.

As you can see comparison, M50 crankshaft vs. M54B30 crankshaft, and I was told S52 crank is the same.
I weighted them M50 weights 18.96 kilograms, and M54B30 crank weights 23.50 kilograms.


Comparison of M50tu piston with rod and M54B30 piston with rod. Notice the better design of the M54 piston? Thinner piston rings(less drag more power), top edge of the piston is machined to prevent edge glowing hot edge that causes detonation. Despite the smaller size M54B30 piston with rod is 8grams heavier, that may be do to denser material.


M54B30 pistons installed into M50tu block. I reused the piston rings, they were fine, no need to waste money. I did ran a cylinder hone up and down trough the M50 block just to clean it up a bit.

I decided to reuse the 220k miles rod and main bearings, they show no major wear and there is no need to spend money on new ones. Besides this is a “budget 3.0L stroker”

I did however used the old school method of checking for correct clearance , the plastiguage , just be shure. Very easy to use and cheap.

Some of you who are arrogant BMW mechanics are probably thinking that I am an idiot and that stroker engine would have crazy high compression because piston head is flat. But compression will be an actual 10.5:1 ratio, same as S50/S52 and you can run cheap 91 octane safely. How can that be? Because in M54b30 piston will sit 2mm below the deck at top dead center.

[EduardoGomez]

From the deck to the bottom dead center of the piston head, is 92.2mm, this would make this stroker configuration an actual 3.1L by atmospheric volume. 92.2mm stroke and 84mm bore would make it slightly over 3050cc by volume. But by the actual stroke it is still 3.0L. In my opinion this is better configuration than S50 engine. You got a strong thick wall M50 iron block with modern design rotating assembly and detonation fighting piston design with thinner piston rings. Noticed how I cleaned the surface of the block with 400 grit sand paper and water, all the way down to factory machining marks, that’s the way to go. If your core block is warped and you need to spend ton of money at the machine shop, then you are doing it wrong. If parts require machining then you got thrash engine that is not worth your project.

A M50tu E34 oil baffle has to be modded for the rods to clear as you can see in the photo, also the circled red needs a slight tap of a hammer to clear rod of piston six.

I cleaned the surface of the head with sandpaper and water, all the way down to original factory machining marks, if your cylinder head needs resurfacing then you are working with thrashed engine, not worth of building for your project. Get a known good running engine. Better yet buy a running car, like I did.

Only a true BMW enthusiast will do his valve job on the kitchen table. All the valves and guides were in perfect condition even the valve seals, I did not have to do this but I did it anyway, it is just fun to do it. Some people do drugs, get drunk, and I do valve stem job replacement on a weekend. The way you can check if valve stem seals are still good just poke one lightly with small flat screwdriver trough side of the valve spring, if its soft and has some give, then it is good, no need to be doing valve jobs.

It is like a new head, ready to go. No money invested.

I don’t like paper gaskets, they will just leak at some point. I do like to use Permatex ultra gray silicone, once its dry it is like hard rubber, I never had problems with leaks when I used this silicone. Trick is to use light coats. Some people don’t know how to use silicone and just put too much and it clogs oil pickup tube. If you are stupid then use gaskets and waste money.

Notice when all is torq you can see a nice even squeezed beam of silicone, that’s when you know you got it right.

This is a 8/1995 improvement for M5x series single vanos adjusting spring plate, it makes the adjustment tighter and eliminates vanos noise. I went to the same salvage yard to buy this and the arrogant salvage yard guy(Duane at Sport Car Recycler) did not know what I am talking about and argued with me that if BMW wanted it there in earlier models it would have had it. Dealer wants $150 for these parts, but I managed to find them locally for free when I bought me some S52 cams with trays and lifters for $250 that I needed for this project anyway.

No need to waste money on special timing setting tools, I did it without any special tools, it is just a matter of using common sense and understanding how parts work, I am willing to explain how to do it without tools another time.

Reused old gasket, cleaned it, then put some light coat of same silicone, I don’t have to worry about this oil filter housing leaking ever.

I decided to refresh my A4S310R(THM-R1), better known as 4L30E automatic transmission with some new internal seals and clutches. For the clutches that required special tools I did not bother to take them apart, I just replaced what ever was easy and left other things alone, anyway I tested the tranny prior from removal and it shifted fine. All old clutches were still good despite high mileage. Rebuilt kit is $150. And I don’t have to worry about expensive clutch disc and pressure plates.

Rebuilding the transmission on my kitchen floor. Yeah Vin Diesel style baby.

Time for my E30 to get that old bust still good M20 out. I sold the engine prior to removal. Got $400 out of it and that will help my project budget.


Pulled the M20 out and sold it the same day. Thanks to local BMW forum www.azbmw.org

[EduardoGomez]

Brake booster out of the 1992 320i, $20 from local you pull it junk yard, in my case it was easier to cut the rod and then reweld it then to thread it. Green E21 mounts, later I made some aluminum adapters that I put on top to correct the angle and lift the engine few millimeters.

Engine with 4L30E will go in just as easy as M20, as long as it is all stripped, longer trans cooler line has to be installed prior to installation. Also the ebay supersprint knockoff headers won’t clear, they have to be installed later. I eliminated the heater system.


I overdid it, but the driver side channel has to be slightly kicked in for the selector cable to clear properly.

Stock E30 cross member will fit fine, sense I used E21 manual tranny mounts, I had to re-drill the transmission holes and cross member holes. You can see it in the picture.

I had to get the drive flange from 1995 318i as well as the whole driveshaft, the front section will have to be shorten to about 5mm, and you can’t use the dust cover. This is because E36 318i driveshaft is still one inch too long, and stock E30 driveshaft two inches too long. Anyway driveshaft works great.

This transmission uses different system of control, so two holes will have to be cut out, the same ones that you see in the E34 interior.

Harness and selector cable installed.

E34 selector installed, I machined the rod so that E46 selector knob can be used. As for the wiring, very easy, looking at wiring diagrams, E34 selector has an internal reverse light switch, and has to be wired differently. Maybe I will write up later what goes to where but only about 6 wires need to be configured out.

Trans computer, the black box named Getriebesteuerung sends a “fault” signal trough pin 29 a gra/brown wire, a negative signal, and I installed a switch and a LED, so that I can read codes if there is a limp mode fault. These transmissions have very sensitive computer, and they do go into safe mode often. BMW later had less sensitive chip eprom programs made to reduce the fail safe sensitivity.


A dual brake light switch has to be installed from E34 or some other model. Just follow wiring diagram on how to wire it to the ECU.

As you can see all finished. I installed LED , A to M indicators, that get grounded by the ECU pin 10 and 31.


I made a transmission oil cooler out of the stock E30 oil cooler, I reversed the metal lines, cut, and then welded on them lines from E34. Cooler is big enough and gets plenty of air. I bought some 12mm bulk oil cooler lines from www.autohausaz.com

I manufactured some support using metal pipe and E30 tranny mount, to prevent engine moving forward in case of engine mount failure. Kind of works the same way as stock E30 with automatic tranny.


Used stock E30 exhaust keeper, reused stock E30 exhaust, into supersprint headers. It will do the job.

I used E34 A/C hose section, cut it, then welded on E30 A/C hoses. I used two cans of real R-12 and A/c blows very cold. Notice the lower radiator hose? Looks like it is made just for the swap. If you buy Gates brand hose part number #21900, you cut in half and you will get a upper and lower hose for your swap that look like its made for the swap application, if you cut the hose at the wrong spot you will have to buy another one. Cost of hose, only $18 and you get upper and lower, can’t beat that.

Very cheap and effective high flowing cold air intake. I cut the front section of stock E30 air filter box bracket, then used the rear section plus welded on some E34 P/s reservoir bracket to the section and made a support for the air mass meter, and then drilled the front of K&N filter and manufactured the mount so that the whole filter is secured and does not touch other parts and get worn.
1. Home depot gutter flashing, easy to cut and fold, good enough to steer away hot air from the radiator
2. Home depot two hole pipe strap
3. K&N filter RC-4690 $60
4. Stock E34 air box adapter and velocity stack cut and filter put on.
5. Welded on custom C-shape support bracket for the maf


Both the 413 ecu and tranny ecu will sit in the glove box, I still need to manufacture bracket for that. The 3 relays are held but cut stock E34 holder plus cover.

For the ECU use the performance chip for early 1995 M3, gray sticker 506 ecu. Or invest about $100 and burn your own chips. www.moates.net under ”chip programming”, I already posted the proper files at www.ecuproject.com, free registration required, and instructions how to tune your own Motronic ecu is there under Motronic section. Once you get into it , its not that hard and you will love it.

I know I am providing lots of good information so that people can enjoy their E30 for cheaper, but some moderators don’t like that. So I might be banned from the forums after I posted all of this. So if you don’t see me here, don’t be surprised.

And the results? All I can say is WOW, I should of done this swap before. I still need to get LSD differential with better gearing than 4.10. But still, car moves like a V8 muscle car off the line, I know at ¼ mile I could have very impressive 60 footers. I have a 2002 330ci and my now swap E30 is much faster. This 4L30E transmission shifts smoothly, and when that kickdown switch gets nailed, tranny shifts to low gear and rear tires brake traction,
Poor man’s S50 how to do list:
Get good M50tu equipped car for less than $1000, very doable, sell off the smaller stuff on ebay, and bigger stuff localy. -$500 at least, scrap yard will give you $300 for the engineless car. Sell your M20 engine like I did.
Get an overheated or good M54B30 block, these are not hard to find, they got aluminum blocks that crap out under heat, and shops and salvage yards don’t know about the stroker thing so you maybe able to get it for cheap. I payed $500 and sold the bare block for $150 and still got the oil pump and main pulley. Reuse the piston rings they are better then new aftermarket ones.
Get S50 or S50 camshafts, I payed $250 for mine and got trays and lifters with it. You can machine down the M50 trays for S52 cams to fit. Cams run from $200 to $350 used.
Gasket for the head, for M50tu, $120 plus silicone, get the older version front and main seal they have the spring and work better than springless lip new design seals. $20
Buy a ebay chip for 506 ecu, they are usually just copies of dinan and will work well $40, or spend $100 in eprom burner and few SST27SF512 chips and burn yourself free programs that I posted on www.ecuproject.com
You can easily build your self a nice S50 equivalent M50 engine for under a $1000 on basis of buy the whole thing and sell the stuff you won’t need. If you are stupid loser then even the best instructions can’t help you then just buy a thrashed S50/s52 block for $2k and spend more money machining it all.
I hope that I provided enough of great information, and I hope you like my post. Thanks. Take care. I will go ahead and enjoy my on a budget S51 swapped e30 now.

[e30s50dan]

Well......DAMN!!

[nando]

used rings, used bearings, sillicone "gaskets" everywhere, auto trans.. :(

[CorvallisBMW]

Well isn't that interesting... I like the idea of a 3.0 m50. Props to you for doing something different :up:

[sticksdaman]

Subscribed!

Interested to see videos/ Dyno results. Curious to see what the Powerband/Torque curve is in comparison to an s50.

[xwill112x]

nicely done. good to see the community expanding the 24v section :)

[Adrian_Visser]

+1 on doing something different with the auto trans.

-10 on re-using bearings and rings, I think you will be sorry about that in the very near future.

[trackjunkie21]

I love the ingenuity, I really do. But if you are going through all that work, I would have put real gaskets and new main bearings and rings. Do they really cost that much? Better do it right the first time then having to pull the motor because it loses compression or starts knocking. Everything else is top notch.

[Jalves619]

so MarkD tune?

All kidding aside It's nice to see people still finding some new ways to go about the swap.
Do you have any videos of it running?

For those that know turbo setups better than I, Do the M54 pistons look like an upgrade if you were planning FI? It seems the smaller ringlands wouldn't be able to hold nearly the same boost as the M50 pistons.

[nando]

no, for FI you want that space between the top of the piston and ringlands. the M52B28 piston crowns are quite beefy, which can be good for that purpose.

[Danny]

I mean... I GUESS.

[moatilliatta]

compression numbers? ;)

[sleepingbeauty]

compression numbers?

+1

if I have a s52, can I put m54 pistons in and get some extra juice?

and you stuck with the m50 crankshaft correct?