MyE28.com

M70 is another kettle of fish. bmw4aaron is doing that swap right now in an E28. The motor in stock trim doesn't make tons of power and requires forced induction to make big numbers. Freight train torque, though.

That's what I'm thinking, and Paul Burke too. ~300hp/tq stock is plenty and a cruiser v12 could take this thing to unheard of levels of uniqueness. And once again, a running parts car is cheaper than a bare LS1. If I really lose my sanity, twin turbo power will be there for me. As of now consider this a V12 project.

You will have trouble with the trans, but nothing that can't be overcome. I am willing to assist in the design of an adapter plate to use a differnt trans, though. Otherwise the only manual option is an expensive 850csi trans. I recommend you check out the forums dedicated to ferraro and lambo kit cars for info on running the M70.

Thanks. I talked to my mechanic and he said 5/6 speeds from M60 equipped cars would be a direct bolt up. Is this not the case?

It is not correct as far as I know.

How soon until you get this thing driveable? I'd think you only have 8-10 weeks until your semester at school is over.

The deadline by end of school is just to have it rolling on suspension. Thats all, and I plan on continuing the work in my garage at home during summer and the following year

Just downloaded a fantastic 50 page technician service manual for the M70 engine. I think the best route to obtain the engine will be an all day visit to the pick n pull when I can take the engine and wiring harness all at once. Of course this won't happen until I have the suspension finished.


The v12 will actually sit 1-2" lower than the six because I don't need to tilt it at all. The top of the valve covers will be about 15.5" above th frame rails at th front of the car, so if a line were drawn from the top of the valve covers to me it would intersect about 3" below my shoulder.

Buy the whole car. It'll be cheaper in the long run and you can sell off parts to help pay for it (like the diff, seats, lights, etc.) You will likely want the rear arms too because they fit your setup and have bearings for the pivots. That, and you get big brakes with the car that will fit your car (not that you really need them.)

mooseheadm5 wrote:Buy the whole car. It'll be cheaper in the long run and you can sell off parts to help pay for it (like the diff, seats, lights, etc.) You will likely want the rear arms too because they fit your setup and have bearings for the pivots. That, and you get big brakes with the car that will fit your car (not that you really need them.)

I get your point with the brakes, but what rear arms are you talking about? The subframe or just the arms attached to it? Should I wait for a runner to pop up on craigslist? Cheapest I could get one is probably around 1500.

sbeckman7 wrote:

mooseheadm5 wrote:Buy the whole car. It'll be cheaper in the long run and you can sell off parts to help pay for it (like the diff, seats, lights, etc.) You will likely want the rear arms too because they fit your setup and have bearings for the pivots. That, and you get big brakes with the car that will fit your car (not that you really need them.)

I get your point with the brakes, but what rear arms are you talking about? The subframe or just the arms attached to it? Should I wait for a runner to pop up on craigslist? Cheapest I could get one is probably around 1500.

The rear trailing arms bolt right up.
You can usually pick up a runner for less than a grand, especially if the trans is leaking and there is any body damage. Blown rear self leveling also costs much to replace so people tend to give up on them. This is one such example. I know it is the wrong coast but:
http://raleigh.craigslist.org/ctd/2294894421.html

I would bet that out there any 750 that fails smog for a bad cat would pretty much be totaled as well.

Thanks for the inspirational ad! The only one near me is a runner; owner is asking 2400. Luckily I have plenty of time to sit and wait

sbeckman7 wrote:Thanks for the inspirational ad! The only one near me is a runner; owner is asking 2400. Luckily I have plenty of time to sit and wait

It sucks when a car is running, doesn't it?

especially when you're trying to buy it!

Stick with runners that don't move (or have a trans stuck in limp mode) or leak PS or trans fluid uncontrollably.

Will do. Thanks a lot for the advice. I picked up the threaded collars today from school by the way, should have them sent by Friday.

Just finished reading the Tech manual. My god did BMW pack in the electronics! It's clear to me that this will be a much more complex engine to use than an M30 or LS1. That said, I am even more excited to use this powerplant due to the fact that it will be a much greater challenge and I will have much greater rewards. Since cruise control is integrated into the throttle bodies, I will have that. The thing I'm most excited for is ASC, specifically with an "off" switch. This car just became useable in a much greater variety of conditions.


If anyone has experience with this drivetrain, I do have a few questions.

1. Since the power steering and a/c pumps are driven off of the serpentine belts, do they need to stay on even if I am not having PS or A/C or can a smaller belt be found?

2. How is throttle response with the electronically actuated butterfly valves? It seems very crisp from what I gather from videos, but after driving my dad's e39 with throttle by wire, I am still wary. The pedal has an unbelievable amount of delay; I'm surprised the make of The Ultimate Driving Machine let it go into production like that.

3. What sort of warnings will I get from not using the automatic transmission? Will it affect the car's performance or top speed in any way?

4. Will the 3.25 E28 diff work or will I need the one from the e32? Is the e28 diff considered a large case or medium case diff?

Finally ordering the Koni's and last coilover bits tonight.

How are you going to get a signal from the wheels for the ASC?

tsmall07 wrote:How are you going to get a signal from the wheels for the ASC?

If he has an entire parts car he could just steal the parts off of that.

rmiddendorf wrote:

tsmall07 wrote:How are you going to get a signal from the wheels for the ASC?

If he has an entire parts car he could just steal the parts off of that.

Yeah, I get that, but I don't think the tone rings and sensors will just bolt up in an e28 hub. I could be wrong, of course.

May have to use e32 struts. I'll already end up using the rear arms so why not the front's too? Just need to cut off the oem perches again and weld on another collar...

Here's some info
http://www.mye28.com/viewtopic.php?p=223309

The existing ABS system can provide the signal for the ASC.
You should be able to run it without the auto trans with no issues.
You can replace the PS and AC with idlers or redo the system with a shorter belt to remove them.
The 3.25 diff will be fine depending on which transmission you use (i.e. what ratios it has.) E28 is medium case, 750 is large case.
Throttle response is fine, but I'd do away with it due to the complexity. There are 4 computers on a 750- 2 ECUs, 1TCU, and a throttle computer. If you wanted to run it on Megasquirt or other standalone you could manage it with one computer and skip the traction control, electronic throttles, etc.

mooseheadm5 wrote:You will have trouble with the trans, but nothing that can't be overcome. I am willing to assist in the design of an adapter plate to use a differnt trans, though. Otherwise the only manual option is an expensive 850csi trans. I recommend you check out the forums dedicated to ferraro and lambo kit cars for info on running the M70.

Is the 850CSi transmission the same as the one in the 850i/Ci twins? I don't know and really don't know where to start researching it.

I'm going to be 'ants at a picnic' and say that you really might be better off with a turbo'd M30. Far simpler design with much less electronic complexity. Plus if you wanted to rebuild an M30 it would be much easier than rebuilding an M70.

The 850Csi was the only manual v12. The i/ci were auto.

sbeckman7 wrote:May have to use e32 struts. I'll already end up using the rear arms so why not the front's too? Just need to cut off the oem perches again and weld on another collar...

Here's some info
http://www.mye28.com/viewvtopic.php?p=223309

You won't have to.

mooseheadm5 wrote:The 850Csi was the only manual v12. The i/ci were auto.

I hate quoting Wikipedia but:

The 840Ci (V8) U.S. models were each equipped with a 5-speed automatic transmission. The 850i/850Ci (V12) models each carry either a 4-speed automatic transmission, 5-speed automatic transmission, or a 6-speed manual. The 850CSi model only came with a 6-speed manual transmission.

http://en.wikipedia.org/wiki/BMW_E31

And this one for sale:

http://www.autotrader.com/fyc/vdp.jsp?c ... 90377&ct=p

And this one:

http://www.autotrader.com/fyc/vdp.jsp?c ... 85747&ct=p

And this one:

http://www.autotrader.com/fyc/vdp.jsp?c ... 91627&ct=p

And this one:

http://www.r3vlimited.com/board/showthr ... light=850i

Ok, now I'm just being an ass. Sorry.

rmiddendorf: firstly, an M30 is not an M70 In all seriousness, I want the V12 just to say I have a V12. It's just special and unique. Im hoping that I wont have to be digging around under the valve covers fixing things too much because the engine is remaining in stock trim. And I'm actually looking forward to all the electronic stuff, hoping to come away with a bit of experience working with them. On a side note, I had no idea how many 850's had a six speed!

Paul, thanks for the info, as always. Just made my day a bit better

You are correct. The 6 speed was available for a small number of non CSi cars.
Still, the trans is super hard to come by and expensive when you find it.

Yeah I wouldn't even bother trying to find a 6-speed, they're in excess of 2.5k used... Adapter plate and the G265 for me.

Did some more cutting and welding on the struts today but didn't quite finish. I also realized I made a mistake on the first strut: I shortened it by cutting off the threaded collar instead of taking out a section and rewelding it. If anyone has a bad strut or one from a donor car that they dont need, I could pay for them to saw off a few inches and ship it. I'll do some hunting on the FS threads as well.