Build Status: Complete
Words & Pics: Kieron
Contact Author: E30owners Profile
This all started just after Christmas last year , when a got a Call from Lenny .
He told me he was thinking of putting a s50 into his M3, of course my first question was “what happened the s14″.
He had bought the car as a none runner, with an M50 sitting in the engine bay but with no ecu.
Now I am no engine snob but a M car desirves a M power plant, and there’s none finer than a S50 B32.
I reminded Lenny that S50B32 engines all have ews2 (chipped keys) and to make sure that when buying an engine to make sure he got ecu and matching ews unit and key, to which he informed me he had a 96 m3 evo sitting at the house and it was a runner.
To any one thinking of doing this conversion take care to get the above Ecu / Ews module and matching key and transponder ring(around the ignition barrel).
If you fail to get any of the above it going to get expensive VERY EXPENSIVE, the problem is that the key has a chip with a rolling code (ews2) what happens is when you try to start the car the ews module trys to read the code from the key, this code is then compared with the one in the ecu if they match happy day the starter will fire up and away you go, but if your keys code doesnt match then ecu will shut down so no fuel and no spark and the Ews module will inhibit the starter signal,Bad news! you or I are not going to hot wire you way out of this one .
The ews module IS NOT just a passive module it is also paired to the ecu. There are ways around this by getting some one to alter the ecu software, but I havent seen it done, and think ews is a nice security feature to have.
Your only other option is custom ecu, how ever this is again no cake walk, first of all these engines have double vanos (Variable valve timing) but unlike a lot of variable valve timing its not just a two postion type like m50/52, its constantly variable with about 60 degrees of movement on both intake and exhaust.
There are only a few after market ecu,s that can run this and you have guessed it they are expensive, the motec m800 is one and thats around 4000 euro with loom etc…
Second problem is the shear number of variables this engine has, which is a hugh problem for Mapping you shiny new ecu.
Imagine a standard engine with fixed cams all you have to worry about is fuel and ignition maps at given loads, so basically get a few spots right at say 1000 rpm intervals then fill in the dots this can take a day or so of mapping may be more, how ever with the s50 you now have Double Variable Valve timing to factor in and changing the valve timing will change the fuel and ignition map, its like adding two extra numbers in the lotto, you can still win it but it will take you a lot longer and that means more CASH!.
I spoke with someone who mapped one of these on a haltec ecu and he said it took him FIVE Days of mapping, and at that he reckoned he still could have spent longer. That’s a serious amount of cash.
Now sitting in you donor cars is an ecu that some men in white coats have spent thousands of man hours mapping playing with every variable possible (temp humidity altitude) and who ever you get the map a custom ecu wont be able to simulate any of these.
The siemens ecu is a super ecu so fast that it uses the vanos to vari valve duration and also exhaust gas recirculation.
My point is Get The Ecu ! from the donor car.
Sorry went a bit off track there, so any way I drove down the lennys house and met the man him self (A Gent !).
I was very envious of his super shed, but more so once I got inside I first saw a beaut of a e36 evo (I felt a bit guilty about braking it) I started it up and it purred like a kitten no nasty vanos noise, I was happy with the donor engine, Lenny told me it idled a bit rough once hot but drove fine.
Ee then went through to the real car the E30 M3, what a nice looking motor and a lovely colour as well.
That was it I was hooked I had to get that M3 rolling again, so the following weekend the mammoth job started .
The first week end was spent removing the S50 from the donor car, they are quite a tight fit the e36 chassis legs are actually closer together than a e30s.
Once out we stripped the sump and oil pump off as the e36 sump bowl is right where the e30 sub frame is, so you have to fit a e34 sump.
You will also have to lose the S50 B32 oil pump as it has a dual oil pick up that will be in the wrong place for the e34 sump.
You can fit the pump from a s50 b30 with m50 pick up tube from a e34, or a complete e34 m50 oil pump and tube.
When fitting the oil pupm drive sprocket use a bit of locktight on the nut they can come loose.
While we had the engine out we decided to check and renew a couple of bits;
The water pump looked almost new but the thermosat was changed
We also split the engine an gearbox to check the clutch and flywheel
The clutch looked fine and pressure plate and flywheel, in fact they looked as if they had been changed recently,
the spigot bearing did not look so new and dual mass flywheels put more loads on these little feckers, they only cost a couple of euro so we replaced it.
Now for any of ye that havent had the pleasure of replaing one of these the can be a bit of a pain in the arse to get out as they are pressed into the crank shaft and you have no way of griping it to pull it out unless you have a fancy internal bearing puller.
So I have to go old school pack the center of the bearing full of grease then find a nice tight fitting bolt and drive the bolt down the center of the bearing with a large hammer the grease will get behind the bearing and push it out like a hydralic ram.
Once out its easy to tap the new one in.
Here is the S50 with it original dual pick up oil pump.
And this is with the M50 e34 oil pump. We replaced the crank oil seals and gave things a genaral clean up.
The next job on the agenda was drilling the e34 sump to accept the oil drain pipe from the plenum box, we drill and taped the sump and fitted the spud out of the s50 sump . we had to remove a baffle out of the sump to get in and fit a lock nut to the spud and to clean out the swarf from the sump , the oil drain pipe is just under the altenator in the picture.
We also had to modify the dip stick as it runs straight in to the oil pressure accumulator for the vanos.
Once all that was done, I set about removing all the excess baggage from the S50. These engines have an auxiliary air system which bascially helps to heat the cats up in the morning, this was to help emission rating and is not need for anything we care about (POWER).
The system consists of a belt driven air pump (looks like a aircon compressor) and a couple of vac lines an ecu controled solenoid vavle + the main air line that bolts onto the block beside the exhaust.
With all the pipe work removed you would be left with a hole in the block (not a great idea) but lucky enough South african model’s didnt come with the air system, so you can order a blank plate from bmw.
Part numbers for the plate and gasket are
11 72 14 02 416 = plate
11 72 13 18 467 = gasket
I disconnected the electrical connector from the air pump which operates the clutch from the ecu, and it causes no problems, I am sure if you scan the ecu it will show up as a fault but it doesnt cause the car to go into limp home mode.
Here are some pictures of the plate in place.
The next job was removing the ews system and relays from the donor car.
There is not that much to it really but its well worth having from a security point of veiw.
I first removed the X20 plug this is the plug on the bulkhead that the engine loom plugs into this carries all the connections between the car loom and ecu+ all your gauges and lights for engine. It is similar to the c101 plug beside the fuse box on the e30 but has more pins.
The e36 also has an additional plug x69( I think) this carries oil temp signal and data signal to dash for oil level.
The e36 oil level sensor works in a different way to the e30 type sensor and wont work with e30 check panel, but one from a e34 will work and fits the sump, but you will have to bring new wires from the sensor to the car, I broke these wires through the X69 connector as there was spare ways in it and none in the X20 connector.
I just cut the X20 and X69 plugs off leaving about six inches of cable so I could get a nice joint on them.
Then I removed the Ews2 module fro the donor car, this Module lives under the dash its the one with the yellow plug dont be fooled by all the wires going into this, it is tied into the locking system and the radio but doesnt need the inputs so they can be forgoten about, what you do need is the transponder module and inductive pick up, the transponder lives behide the clocks on the e36 and the inductive ring is clipped on over the ignition barrel, again I just cut six inches of cable with both of these plugs.
I wont go into the wiring unless someone wants it as its a bit boring, if any one does want it let me know and I will put it up on a separate post.
Once all of the stuff was removed we when about fitting the engine. We fitted it with the gearbox attached as the six speed is a big old beast and didnt fancy waltzing around the pit with it over my head trying to get it to spline in, I always fit my engines with gearbox attached. It was fitted using original alloy mounts and e28 m5 rubber mounts, there are probably other mounts that would work but I like these as the fit well and are very stiff so there is not much movment.
The engine went in easy enough but the six speed is too long for the rails in the e30 chassis that the gearbox mount sits into, its no major ordeal though we made up two bits of heavy steel plate about 200mm long with a lip on it to stop it bending and drilled three holes in it two to bolt it into the rails on the car and one to bolt the e30 gearbox mount to. With that done the gearbox was soild as a rock.
We used the e36 gear linkage and it fits perfect, we also fitted Z3 short shifter.
With all this fitted we could now measure the prop, and got 1350mm from back of the flex coupling on the gearbox to the front of the diff flange, we just shortened the original E30 M3 prop.