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Low Tech V-12

Discussion in 'E32 (1988-1994)' started by Bill Boro, Mar 6, 2010.

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    Bill Boro

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    I have the a chance to pickup a 1989 750 il engine for possible use in a 1947 Kaiser-Frazer project car.

    Does anyone know of a thread or source of info on running this motor in a "'manual mode" without the brain box via carbs and a conventional ignition system?

    I also understand that this motor will mate with a manual 6 speed transmission from a 540. Can anyone recommend a source for information on this?

    The conversion would replace a 100 hp cast iron 6 cylinder w/ a manual 3 speed, therefore I don't care if the conversion results in less hp then the factory setup.

    Thanks!
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    John in VA

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    MGarrison

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    I suppose it might be possible to use Megasquirt or umm.. Ostrich (? Ostrich-Tune?) to make a standalone fuel-injection control system...
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    bcweir

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    That 540 transmission will not bolt up to a 750...

    ..not without a whole lot of modification to the bellhousing.
    The M70 V12 in the 750 and the M60/M62 in the 540 are two completely different engines and they do not share parts (or transmissions). The bolt patterns on the engine and transmission are not going to line up to one another.

    If you're looking for a transmission that will directly bolt up to the M70, an 850CSi six-speed manual transmission is your ONLY option. Transmission and bellhousing are a direct bolt on. You're also going to need both DME's, the EML module, and you will have to adapt the wiring harnesses.

    Some other alternatives that are known to work are Audi and Porsche transaxles. The Porsche transaxles are super heavy duty but also super expensive (between $6K to $14K to start). You can make do with an Audi manual transaxle, but you're looking at an adapter plate and probably a custom bellhousing also.

    The Megasquirt and Ostrich custom ECUs are known as home-brewed brainboxes. If you don't have the technical knowledge for DIY (do it yourself electronics) or the thick wallet full of dollars to have someone else do it for you, you might be better off working with the existing BMW electronics.

    Do a search on the Bimmerboard forum and you can find some of the members that have successfully converted the M70 with work with a six speed manual transmission. One guy you want to do a search on is named Sanjeev. He has a 750iL turbocharged M70 backed up by a six speed manual transmission. He's the guy you want to talk to about running the M70 with a manual transmission.
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    mooseheadm5

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    There is no reason you can't hang carbs on it, but you may have to come up with some sort of standalone crank trigger ignition system. I say go for it, but you will need to spend money on a trans. Lots of money.
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    CRKrieger

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    I can sell you a freshly rebuilt 4.6 liter 'stroker' AMC I-6 with about twice the power of the original engine you're taking out. You'll have it installed and working long before you finally decide to gouge your eyes out over this V12 fiasco you're proposing.
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    bcweir

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    I agree with Krieger's assessment of this project

    I believe his offer would be a much simpler, much more practical, and much less expensive alternative to your six speed carb V-12 proposition for the following reasons:

    • Parts availability: AMC made various versions of the I6 for DECADES, vs. the relatively brief 15 year run of the M70/M73 before going to the complete new and different N73 direct-injection engine of the 2002-present 7-series. Nearly all of the parts available, including the transmission, bellhousing, intake manifold, heads, etc. should be quite plentiful and easy to acquire. Many American Motors and Jeep vehicles continued to use the AMC I-6 long after AMC's 1987 purchase by the Chrysler Corporation.
    • Cost: The availability of parts should dramatically lower the cost of this project, while on the other hand, parts for the M70 tend to be very expensive.
    • Fabrication - you are already looking at having to hand-fabricate a intake manifold using carbs. Unless you have specialized welding and metallurgy experience (you're going to need to know what types of alloys will give you the best combination of heat transference, compatibility with various welding processes, as well as the size, shape, and placement of the carb passages, all make this a very expensive project), you would really be getting yourself into a hugely expensive proposition. We haven't even discussed the cost of fabricating a custom bellhousing and adapters to mate the transmission to the engine, or the cost of fabricating a new engine management system from scratch.

    I am somewhat curious about one thing though. The number one reason most enthusiasts hunt up BMW V-12's is that, for the money, that option is probably the cheapest bang for buck horsepower out there when it comes to V12 power. However your statement suggests that you don't care if the end result is less power than the engine you are replacing, which is 100 hp out of your original engine. So I am a little confused by that statement considering that the project would be less expensive going with the stock fuel injection setup and the 750il's automatic transmission. If you're insistent on carbs and a manual transmission, I might suggest that a BMW M10 4-cylinder would more than meet your power needs (most non-turbo M10 engines made anywhere from 60 to 120 horsepower), lots of 4-speed and 5-speed manual transmission choices, as well as plentiful carb and fuel injection options.

    The same advantages would be available going with a Ford or GM V8.

    You're also going to need to fabricate a custom K-brace as well as possibly a custom oil pan. The BMW V12 actually has two oilpans, an upper and a lower one. A K-brace is a structural support that will be needed to mate your engine to the rest of your car's engine bay. Again, the price is going to go way up for the BMW V12.
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    Bill Boro

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    Thanks for the interesting comments.

    As for the I-6 AMC approach.......... I drove a Rambler Classic and an American when I was in college during the early "70s. I would rather put a blower on the existing engine before I would drop in another made in the USA straight 6 (like Kaiser did before they stopped making the cars). A Small Block Chevy (SBC) would be cheap and easy. I have swaped them out in other cars but in my opinion the SBC lacks the class of a BMW engine in a car with a name like Kaiser.

    I would probably be more interested in a 635 engine with a 5 speed than a SBC or another American engine.

    I am an Electrical Engineer and a certified welder (no connection between the two) Fabricating engine & transmission mounts are no problem, neither is checking sensor outputs and building an new wiring harness. However, at my age I don't care to learn a new software language to recode a brain box(es).

    The reason I was asking about the manual approach is one of the possible engines is out of the car and has a torque converter but no trans or brain box. The other is in a car that had a small fire directly in front of the driver side fire wall. I am concerned that the resulting shorts may have cooked other major components.

    I know that some of the 1970s Jaguar and Ferrari V-12s used GM automatic transmissions.Staying on the BMW theme,does any one have enough experiance to know if the earlier 750 transmission can be run without the logic similar to a paddle shifter?

    Thanks for the great comments and input.
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    bcweir

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    If you're looking for "class" you have alternatives

    The BMW E32 750iL uses a ZF HP24-EH transmission. This is an electronically controlled transmission. This transmission utilizes a electrical contact slider mechanism to tell the transmission control unit which gear to put it in.

    The ZF HP24-EH does support a simulated manual mode, by which the transmission selector can be manually engaged into one of four forward speeds and function as a clutchless manual transmission. One possible obstacle you may run into is what's known as the neutral-safety-switch. This switch prevents the car from being started if the car is in any gear except Park or Neutral. I hope this helps you also.

    Again, you're just adding more work for yourself, because in order for your "paddle shifter" mechanism to work, you're going to be doing even more fabricating to make sure the TCU isn't being told to put the transmission in more than one gear at a time. Also, unless you're trying to turn your Kaiser into a "Buick" (my criticism with the E65/E66 7-series), turning this transmission into a column shifted unit would not only be a waste of time, but would go against the character of the car.

    BMW's current line of transmissions were engineered from the ground up to be SMG transmissions, and none of them can be retrofitted to the M70 natively (ie. they won't bolt up without transmission adapters), and then you have get into fabricating custom software for both the engine and the TCU's so they play nicely with one another. It should be noted that the E31 8-series cars were discontinued in 1997, just shortly before BMW started introducing SMG paddle-shifter transmissions. Paddle shifters are pretty neat, but it's going in completely the opposite direction both technically and economically from the simplicity of a row-your-own manual transmission.

    Why not use the M30 big six engine? That engine came out in 1968, and offered manual transmissions also. Some of the early manifolds may have also supported carburetors, as this engine didn't see fuel injection with electronic controls until 1977 with the E23 (first generation 7-series). Please see the following article for more information.

    http://en.wikipedia.org/wiki/BMW_M30

    Your pursuit of "class" is likely to hit some technical as well as economic hurdles. You can certainly get "class" from BMW or Jaguar engines, but you may find yourself having to open your wallet to varying degrees to achieve it. Considering that most people won't know what kind of engine you will have under your hood while you are driving it. It should also be noted that there are a wide number of kit cars and replicas (particularly Ferrari and Lamborghini lookalikes) that use Ford, and GM powerplants. Going with an American engine won't detract from a car's "class" as most people won't know and won't care what you have under the hood while it's working.
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    Bill Boro

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    Perhaps "similar to paddle shifter" was a poor choice of words as there is no intention of mounting anything on the column or steering wheel.

    I have a 1989 Buick Reatta and have no illusions about making the Frazer in to a high performance car, 7series or a Buick. I am aware of neutral safety switches for example, my manual 5 speed 633 apears to have the remains of a safety switch on the clutch pedal that was long gone before I bought it.

    We have owned the Frazer since 1969 and would like to have some fun with it. Even though it is a clean, low mileage the car has little or no real value as a collector car.
    My wife and I were able to resist my kid's request when they were younger to paint flames on it and get moon hub caps for when we took it to cruize night at a local diner. In retrospect it would probably been more fun.

    As you know some people go to meets to sit along side their cars and show whats under the hood. Maybe we would enjoy sitting next to an oversized engine compartment that would allow the use of side draft carbs on the existing V12 intake plenum and not mind driving the 5-6 miles to the dinner while manually selecting gears. Some people consider V-12 engines to be a work of art and put a glass top on them and use them as coffee tables.

    Will have to read up on the ZF HP24-EH transmission.

    Thanks for the comments!
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    bcweir

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    You may also want to consider the unusual dimensions of the M70

    The M70 can be described as a short, tall, and wide engine. You may be having to modify your engine compartment to fit. Part of BMW's goals when designing this engine is that they wanted to be able to accomodate it within the stock E32 fenders. The 750iL uses a different hood, a different wider grille, and different headlamp pockets, but this was mainly a styling exercise to adequately distinguish it from its lower-end stable mate, the 735 which was around $20,000 cheaper. The engine will fit under either hood.

    You will almost certainly need to fabricate a custom K-member as well as a possible custom oil pan, or accomodations for the K-member to accept the stock oil pan.

    I did some additional research on the M70. The engine itself weighs approximately 529 pounds with accessories. You may wish to factor this into your plans.

    I don't need to tell you that you have your work cut out for you.

    Good luck
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    bcweir

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    Bill Boro

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    Great video!

    I would like to do some thing similar but much more stock except for the drive train. Comments in the video have me thinking about passing on the fire damaged car and starting with a better car as the transplant. A driver would give me a chance to check out all the 750 i systems to be reused and make sure they were functioning properly before swaping them!

    Will try to get a picture of the engine compartment posted this weekend. Space is definitly not an issue.
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    CRKrieger

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    This is actually the '90s Jeep 4.0 with a 258 crank that brings it up to ~4.6 liters. I have one in my '01 Grand Cherokee. They put out about 200 hp using the OEM fuel injection (stock 4.0 was ~160). Obviously, there are lots of carburetor options for them if you insist on that.
    Well, there's this. I also have a 3.5 with a 5 speed in a 535is parts car. It was one of these meticulously maintained engines that got 3K oil changes for its entire 250K life - until I parked it because of body rust. All middle '80s 3.5 M30s are the same, regardless of what body they're in, so this is an identical engine to the 635's. Depends on how far away you are. If I don't sell it, it might migrate into a Bavaria I have sitting in a barn. That also raises the possibility of carbs for your M30. I have a set off the Bav. Stock Zeniths. Want 'em?
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    mooseheadm5

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    The M70 uses an electronically controlled trans, but still has a cable shifter. The easiest way to run a 750 engine in another car is to take the engine and transmission wiring harness and move the entire thing over to the other car. It is also recommended that you move the diff over as well, as the trans/EML computers look for vehicle speed vs output shaft speed. I'd go with a big 6 for ease of installation any day, and an M70 only for the wow factor (the big 6 with a modest turbo will eat the V12 alive.) Or you can go with triple side drafts or a 4 barrel, or whatever you want for NA and still have quite a bit of power. If you want smaller and lighter, consider using an M50 based twincam engine. Plenty of power to be had there.

    Bill, where are you located?

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