Found a BMW M73 v12 engine with ZF 5HP automatic transmission and turn-key wiring for sale locally, that's from a 1998 750iL. This is exactly what rusEfi needs as the next test mule, right?
The guy is asking $1500 and I can justify paying half of that. Would anyone be interested to pitch in $1, $20 or $50 for the other half?
The plan would be to get rusEfi control all the bells and whistles of this engine properly - that's two electrons throttle bodies and dual VANOS and etc.
Probably drop it into some old American Iron once it does not require 50 lbs of German wiring.
By the way, block length about 31 inches, block width about 30 inches, block with trans total about 65 inches.
Re: rusEfi needs v12
Posted: Sun Feb 03, 2019 1:50 am
by AndreyB
Wow, there are actually some donations already and this starts to become a reality?!
Re: rusEfi needs v12
Posted: Sun Feb 03, 2019 2:07 am
by Simon@FutureProof
Is it a single Siemens ECU or a pair of Bosch ECUs?
Earlier versions of this engine had a pair of motronic 1.7 ECUs, basically one running each bank, the later ones had it all moved into one siemens MS ecu.
The earlier version may be easier to work with as there is both a lot more known about the sensors, I have all the resistance curves and the stock voltage divider info for the IAT and CLT and it would be pretty trivial for me to get the MAF transfer function from the ECU for you.
If you are willing to get some Bosch sensors into the place of some of the siemens ones then it would probably be ok but good luck with the siemens MAF sensors as I don't think the transfer function is out there.
One other thing to watch may be that first generation of siemens crank/cam sensor. Some of them are not true VR or Hall effect sensors but some kind of weird hybrid, the Z3 2.8 is a classic example and the early cars have these weird sensors. http://forums.linkecu.com/topic/6953-does-not-work-with-crankcam-sensors-m52/
The simple solution to that one is to use a proper hall effect sensor from an M54 engine (Cheapest).
On either version of the engine the TPS should be ok and at heart they are pretty simple v12 engines so over all not a bad choice for a test mule. They are not far off a pair of M20 engines on the same crankshaft.
Edit to add - Also there are conversion kits to put manual boxes onto these from a few places. a cheap ZF box from a E36 328/ E39 528 or 5 speed M3 is a good option, as are the later manual 3l diesel gearboxes.
Yep, July 1998 would have been the cross over build dates for the two versions, so could be either
I am not seeing the electrically heated catalysts so looks to be an M73 (non TU/N version) which is the early engine and uses the dual ECUs.
I just did a bit of digging and it seem that the single ECU version is actually a Bosch Motronic 5.x unit not a siemens unit, but both version are a weird hybrid of sensor generations.
That means you would be in for a weird combo of E36 318i and later M5x engine sensors. Not the end of the world but a little more complex. At least the info is available for them.
Either way still a good unit and I can probably find you a lot of the info you would need.
I know that feeling but your now $25 closer. Its also not worth the $1500, more like $1000 at best cause there really just isn't a market for them.
Even here in the UK you can pick up whole cars running for £1500.
Putting the last 7 digits of the vin number into this link will tell you exactly what was in/on the car, will even tell you the colour and options the car was ordered with. http://bmwfans.info/vin/
Also these lumps are not VANOS engines, even if they were the early VANOS is simply on/off based on calculated load.
Re: rusEfi needs v12
Posted: Sun Feb 03, 2019 12:34 pm
by kb1gtt
You can probably sell the extra copper as scrap and get some money out of it that's allot of copper. The below page notes bare wire is $2.42 per lbs. However other pages seem to show the harness wire or insulation wire is closer to $0.50 per lbs. https://rockawayrecycling.com/scrap-metal-prices/
Unfortunately to get VANOS on a V12 you need to go 2003 -> with the N73 and that also comes with the variable valve lift "Valvetronic" system.
It also is 4 valve per cylinder, coil on plug and an alu-sil block so its 450hp and a claimed 240kg with accesories.
The iron v12 short engine is 150kg on its own according to BMW so built its going to be more like 210+. BMW engine weights online are super unreliable.
That's a funny engine. Two ECUs, individual injector wiring but two distributors - one on each bank. Two distributors and two electronic throttles And SOHC and I wonder how tight is it between the banks inside the V. Any more weirdness like water-cooled alternator or something like that?
That's a funny engine. Two ECUs, individual injector wiring but two distributors - one on each bank. Two distributors and two electronic throttles And SOHC and I wonder how tight is it between the banks inside the V. Any more weirdness like water-cooled alternator or something like that?
The ferraris were the same way. Even the V8s were dual distributor and dual Ignition controller in the 80s and early 90s, then dual ECU in the late 90s early 2000s. I kind of lost touch after that....but the issue was processor speed as I understand it.
Re: rusEfi needs v12
Posted: Mon Feb 04, 2019 6:32 am
by puff
two distributors - easier for the coils. btw, what's its idle speed and max rpm?
I have all the resistance curves and the stock voltage divider info for the IAT and CLT and it would be pretty trivial for me to get the MAF transfer function from the ECU for you.
You seem to know a lot about these Do you know if this epic round throttle body connector is used on anything other than M73? Thinking to get a bench setup at least for the ETB.
Re: rusEfi needs v12
Posted: Tue Feb 05, 2019 7:36 pm
by Simon@FutureProof
The throttle is unique to the V12 as far as I am aware but that does not mean the plug is.
There should be a part number on the plug (BMW put a 7 or 11 digit part number on everything) and from that you should be able to either cross reference the plug with something more common and cheaper or get one direct from the dealer by part number.
Pretty much all of the plugs for the BMWs are available on their own as dealer repair parts if you can give them the part number you need and often it is not as expensive as you would think.
Perfect example is the belt tensioner for the M52 engines, £65 if you ask for an M52 tensioner or using the part number £14 for just the pulley part that screws into the sprung arm as its used on all 4 cylinder cars.
The M52TU engine has a round plug on its electronic throttle body
1433414 throttle body actuator for example, looks like the same 2.5mm pins
Loads of information here, thank you VERY much!
"Each throttle valve is now controlled by two separate stepper motors driving one rotor and shaft (redundancy operation)"
"The pedal position sensor (PWG) now contains three inductive coils for the pedal position input (redundancy operation)"
this EML IIIs is a monster
Re: rusEfi needs v12
Posted: Thu Feb 07, 2019 5:30 pm
by AndreyB
Just paid for a cheap v12 throttle body with a pigtail - but that's in Russia so it could be either 2 or 6 weeks before I get it in my hands.
Re: rusEfi needs v12
Posted: Sun Feb 10, 2019 5:48 am
by AndreyB
Plan B: "I couldn’t get the engine running. I can not guarantee it’s good it cranks but doesn’t turn over. As is $200
we picked it up From Behind someone’s house they couldn’t tell
Is anything about it the car is in pretty good shape for the year selling it as is cause we can’t warranty something we didn’t hear run."
Do not own any v12 yet. I did collect some but not yet enough donations.
Re: rusEfi needs v12
Posted: Mon Feb 11, 2019 6:19 pm
by Simon@FutureProof
Very unlikely that red 750i cannot be made to run. For sensible money maybe not with the stock ECU but it will run.
I know of similar age BMW engines that have sat for 10+ years and still ran with minimal work, even one that sat outside on a pallet for 4 years (under a cover) and then fired right up.
For £200 its a steal.
Re: rusEfi needs v12
Posted: Mon Feb 11, 2019 6:58 pm
by puff
it'd say it's a dream)
Re: rusEfi needs v12
Posted: Mon Feb 11, 2019 8:51 pm
by mk e
I saw the $200 price and figured it was a done deal
Re: rusEfi needs v12
Posted: Mon Feb 11, 2019 9:04 pm
by AndreyB
$50 more for starter.
Bigger issue they are 3 hours away one way considering traffic, I would have to cross New York City to go all the way to eastern tip of Long Island. I am not sure if I can put a v12 in the back of my SUV so would probably have to rent a truck? That would all be quite a hassle and for a not running engine Damn.
Re: rusEfi needs v12
Posted: Mon Feb 11, 2019 10:25 pm
by kb1gtt
Can you rent a Tow Dolly AKA does your SUV have a ball hitch? I've also seen bumper to bumper tow bars. I don't know where to buy or rent them but I've seen them, so I know they exist.
Re: rusEfi needs v12
Posted: Tue Feb 12, 2019 10:57 am
by XXLO
Hallo.
I have a BMW V12. E31 850i with 5.0L M70 300PS auto transmission.
The BMW M70 started in 1987 with the BMW 750i E32. It was the frist german V12 afer World war 2. Mercedes Benz relaesed in 1991 a 6L 48V 408PS V12.
The early M70 has 2* Motonic 1.2 and a EML. The EML controls the electronic gas pedal and electonic trottle bodys. All DME (ECU) Sensors are twice on the engine. Also two fuel pumps, two preassure regulators. (but one pipe back to gasoline tank)
You can disconnect one DME - the cars runs in limp home mode.
The E31 850i M70 cames with the Motronic 1.7, i think this was also the time, when E32 changed to M1.7.
The M1.2 has bigger ECU and 55Pin connector. The M1.7 has smaler ECU with 88 Pin Connector. I think the EML are working wirh both Motronic versions.
The engine with M1.2 has the oil fill in, in the back at the firewall, the M1.7 on the front.
There is a high performace version of the M70, the S70 850CSi with 5,6L and 381PS. Alpina has a 5,7L version with 416PS.
The sucsessor of the M70 ist 5.4L M73. The M73 is available in the 750i E38 and in the E31 850Ci. (the were also 850Ci with M70)
I am not an M73 expert. I think theese has also two DME and one EML. Motronic 5.2.
The M73 has knock sensors, the M70 not.
To identify M70/M73 its good to look at the black cover between the inlet mannifold. M70 is straigt, M73 looks at the firewall like a "V". Also you can look at the electronc throttle bodys.
M70/M73 has not VANOS. M70/M73 are both aluminum engines.
The is a late M73 version with heated catalysator - if there was other changes, i dont know.
Re: rusEfi needs v12
Posted: Tue Feb 12, 2019 5:11 pm
by mk e
Not yet mentioned yet but it seems pretty important., these engines will fit in a Z3
that's allot of copper. The below page notes bare wire is $2.42 per lbs. However other pages seem to show the harness wire or insulation wire is closer to $0.50 per lbs. 
V12 SOHC 24V Single VANOS. 1995-2001. Pre 98 engines were non-VANOS. 150kg/330lbs according to 
