The forgotten V12

[smokum]

Is there a want to upgrade your M70 or M73 V12 engine if it didnt cost an arm and 2 legs?
Bigger valves ,Roller cam, intake manifold ,exhaust manifold and thin headgaskets?
This is a serious servey please post your thoughts.

[ProStreetDriver]

if i had a v12 then yes! but the big question is how much will it cost...

[paulmer]

I think building up the M70 is just cost ineffective..If you're wanting to build up an E31 you probably shoulda gone with the M60 as there are a lot more aftermarket parts for it (I've done lots and lotsss of searched for parts, etc, for both of them)

[mojocoggo]

Restoring the upper powerband of the forgotton M70. That's imPOSSible!

[ProStreetDriver]

nothing is impossible, you just have to put your mind to it.

[RIboater]

nothing is impossible, you just have to put your mind to it.

And your money....

[JimmyBones]

I think building up the M70 is just cost ineffective..If you're wanting to build up an E31 you probably shoulda gone with the M60 as there are a lot more aftermarket parts for it (I've done lots and lotsss of searched for parts, etc, for both of them)

Building any motor is not cost effective and the best I have seen is a dollar per horsepower for a mod on the M60, at least BMW related.

Honestly, I would make headers for the M70 because you can buy a ratcheting pipe bender for a few hundred bucks and welders don't cost much now a days either. Then once you have the measurements written down you can then make headers for other performance minded V12 owners at a good price to earn back what it cost in tools and hopefully make a profit.

[TxDarth]

Building any motor is not cost effective and the best I have seen is a dollar per horsepower for a mod on the M60, at least BMW related.

Honestly, I would make headers for the M70 because you can buy a ratcheting pipe bender for a few hundred bucks and welders don't cost much now a days either. Then once you have the measurements written down you can then make headers for other performance minded V12 owners at a good price to earn back what it cost in tools and hopefully make a profit.

Do you like the color of the emperor's new clothes???

[mudd46738]

What makes the 850CSi faster than the 750? Would it be the heads? They are both SOHC and neither have turbo's. Thats what I have been pondering for the last couple of weeks. I have a client that has one and the 850 has alot more torque. It slaps you into the seat. I would figure the 750 is a little heavier but not by much. Thats what I am going to try. If the wallet permits!!!!!

[Sasa Ivanovic]

rear diff maybe?

[mudd46738]

Maybe..... the 850CSi has 350hp. I would think that they would have at least a DOHC. But they don't. If the heads are diffrent I wonder if they would firt on my 91?? That would just be to easy. Has anyone heard or has seen a twin turbo or supercharger for the V12?

[paulmer]

What makes the 850CSi faster than the 750? Would it be the heads? They are both SOHC and neither have turbo's. Thats what I have been pondering for the last couple of weeks. I have a client that has one and the 850 has alot more torque. It slaps you into the seat. I would figure the 750 is a little heavier but not by much. Thats what I am going to try. If the wallet permits!!!!!Depends on which generation of the 750. The E32 has an M70 while the E38 has an M73. I'll focus on the M70 v S70 as I don't know anything about M73.

First, the E32 750/E31 850i had the M70B50 engine while the 850CSi had the S80B56. By that nomenclature, I think you can tell that the CSi had an additional .6L of displacement. In addition to that, all CSi had a 6speed gearbox with a different differential (pretty sure on this). Due to the increased displacement, I'm sure it has different intake/throttle bodies/intake/exhaust manifolds/different motronic ignition/fuel maps, etc. Not sure what further drivetrain tuning the CSi had.

No M70/S70 had DOHC - all are SOHC.


Maybe..... the 850CSi has 350hp. I would think that they would have at least a DOHC. But they don't. If the heads are diffrent I wonder if they would firt on my 91?? That would just be to easy. Has anyone heard or has seen a twin turbo or supercharger for the V12?Yep. Dinan made a twin-turbo kit for it - google it :)

[smokum]

The only limits on these motors is that there isnt any after market support the way there is for almost any american motor V8 or V6.
Anything on these motors can be made to cost less but there has to be a demand or theses no market

[paulmer]

I know you can buy various aftermarket cams for it..I know Shrick makes a set. There are also people who sell larger pistons than stock..And I guess you can do a top-end rebuild with new stuff. Have the heads flowbenched with overstock valves, retainers, new lifters, etc.

[smokum]

The aftermarket cams are very tame compared to what technolagy has to offer , the other good thing is that some parts between the M73 and the M70 are swapable With out giving away too much thats what im after.
Everyone has just thru the baby out with the bathwater on the BMW V12

[paulmer]

What about the CSi cams?

How much are you looking tp spend on it?

[smokum]

All the cams for all the M70 and M73 cams are tame.
Here do this go get the specs for the diff cams that are made for all 3 - BMW V12's
I know they are all metric, convert them to english system then open up a summit or a jegs catalog look at the comparable cams with close to the same lift duration etc.
Youll be supprised
Id never buy the crap being sold right now id rather make my own

[paulmer]

Also: http://www.kormanautoworks.com/V12.htm

and

http://www.racingpowerplant.com/bmw_m70.htm

[euroshark]

I think for the V12 forced induction is definitely going to be the best bet for hp per dollar. Anyone ever try a supercharged M70?

[smokum]

Also: http://www.kormanautoworks.com/V12.htm

and

http://www.racingpowerplant.com/bmw_m70.htm

I know about both those places. look at the cost

[paulmer]

Well it's not like fabbing up your own cams/etc is cheap/easy either lol

[smokum]

Well we shall see if it is or not. Im not going to touch the lower end at all.

[mudd46738]

I would love to see how much hp a supercharger would make. Is there anyone who has done this to a V12 with success? What about the computer? How many ponies do you let go with the computer? I feel that the E32 750 is a little under powered. I know it has potenial!!!! I love the car and would live with it being under powered than live without it!! I just want more! As does every man, right.

[paulmer]

mudd, get the wokke chips. It's a major improvement

[smokum]

Ya Mudd theres power to be had done by Wokke

[paulmer]

smokum, do you know anyone in E31 community who has wokke chips in their 840? I'd like some info on how they like them, etc. Everyone I know who has a wokke chip in E32 community has them in a 750

[mudd46738]

I will have to look into it.....SOON. There is a punk kid with a merq around the corner and he bearly passed me on friday afternoon. I have to show him what a BMW will do!!!

[smokum]

I dont think wokke has anychips for the 840 youd have to ask him about that.
PM him

Thats it? only 1 person would be interested in the upgrades i listed???
How many would , not if or how.Thats what im here for to see if its worth while to make these things affordable.

[smokum]

I dont think wokke has anychips for the 840 youd have to ask him about that.
PM him

Thats it? only 1 person would be interested in the upgrades i listed???
How many would , not if or how.Thats what im here for to see if its worth while to make these things affordable.

Bump

[Ahhsk]

Are you planning on making headers? what is your background?

As we all know there is an art and science to good header design. Thats not even addressing the welding challenges.

[323I Junkie]

I think the biggest advantage in the M70 motor is hoenstly fuel economy durability and torque.


Dont laugh.



Ive been checking around for about 5 years, I know several m70 owners.
The engine management and design allows alomst 26 mpg highway with a billion pound Il and an ancient aut trans.


I honestly think with a good exhaust and whatnot the damn thing, in a 3300 pound car with a manual will see 30 mpg in a slick car such as my T/A. They make good power for the configuration, and you can get another 20-30 reliably. But it ends there. But, I figure, with its torque curve and a good 300-330 HP...Ill be happy. And like I said, I cant wait to hear what one sounds like through flowmasters

[mojocoggo]

Ive been checking around for about 5 years, I know several m70 owners.
The engine management and design allows alomst 26 mpg highway

Yeah, if you're coasting... Any sort of throttle and it instantly falls to 15-19. If you drive it right, I'm sure you can pull over 20 as a combined average though.

[paulmer]

If I drive my E32 740 "right" on my commute I can easily get low twenties MPG...about 50/50 highway/city.

Ftw.

[323I Junkie]

Well, you know the drill. Out here, a alot of long flat roads, the 750's somteims do better than the 740's, no idea on the e38 though

[JimmyBones]

Are you planning on making headers? what is your background?

As we all know there is an art and science to good header design. Thats not even addressing the welding challenges.

Honestly I would love to make headers for the BMW V12s because the market would pay for a good set of headers and full exhaust even. The 8 series owners would probably buy better than 7 series owners because they are more performance minded generally but if I could make a good set of step up headers for around 2 to 2.5 grand I think people would buy them left and right.

Yes, header design is an art but once a good set of headers is made with the measurements recorded, it can be reproduced easily. Jesse James said it best about the welding on a Monster Garage episode, "you go through a LOT of tubing the first time welding up some headers."

[shogun]

Twin Turbo Update and Recap

http://www.itsystems.net/PersonalPics/850iA/CompletedIntakePlenums01a.JPG
http://forums.roadfly.com/forums/bmw/bmw-8-series-e31/forum.php?postid=5870543&page=1

[323I Junkie]

I spend money on rediculous things, but $2500 for maybe 10-20 HP across a popwerplants spectrum is insance even for me.


You wont sell those "left and right" ant 2000 - 2500, knock a thousand off that and it will sell moderately.


Went through this trying to get Racing Dynamics to put their awesome M30B35 header back in production...


You will always sell a few...but $2500 is mad money for HP. Especially when there is not much else to do after that. The m70 is awesome, but those heads are achilles heels and without addressing those, theres no big power potential. It isi what it is.

Ryan Falconer on the hand makes a V12 that will make your socks go up and down :)

Of course $25000 starting price is a tad more money than most pay for 750/850 altogther.

Ironically, I think money is in converting 840's to LS6 powered cars. Keep the electronics, so the driver never knows you were there...

[paulmer]

http://store.nexternal.com/shared/StoreFront/default.asp?CS=vacmotors&StoreType=BtoC&Count1=247036159&Count2=164176583&Keyword=m70&Target=products.asp

:O

[GR330ZHP]

Well i'm not exactly sure...but this was interesting...E32 with E38 face....

http://www.youtube.com/watch?v=_UO9UQjdF0A

That E39 M5 had a horrible launch btw

http://www.youtube.com/watch?v=R-tRoSmZxjI

[paulmer]

E32 with E38 face makes me very, very sad. :(

Nice vid though. And PS, that sure ain't a E39. But even with the bad start, jesus, the 750 just blew it straight out of the water. So epic.

[323I Junkie]

Good ref on the headers, thanks...dont know how Ive never seen that before

Built to order for 1250 is pretty darn good, and the point is, with them30, theres a lot of room to grow, serious headwork, cam, etc. Easy to build up, iron block..you can overbore easily, custom pistons, etc. You can get a lot of money out of your header , which all the other mods will depend on, unless you go FI. It is not unreasonable to think that with the B35 you could go from 219 to a solid 260 or 280 without stroking it too much..with a 3.8 conversion, who knows. That includes headwork, cam, mass air converison, headers. Examine the percentage gain there and compare it to taking the M70 to 420 HP with NA mods...doesnt happen..Ive heard 360, etc. Its an awesome motor, but a single look at the cutaway of the head and you know where the issue is. Why cant take 325iS heads and monunt them and machine one backwards I dont know, its been discussed before

[smokum]

The hard part is done ,now comes the expensive part.
How many M70 owners is there in the 7er forum?
http://forums.bimmerforums.com/forum/showthread.php?t=1270041

[paulmer]

smokum, you'd find better luck posting in bimmerboard.org/e32

Many, many M70 owners there..most of them haven't really modified them, but there are a few who have done major work..few with kit cars, few with them in E30s and other BMW chassis..even one in a Espirit!

[smokum]

Ill go check it out THX
When i get close to Dyno time ill post every were..:)

[Reed Hunt]

Maybe..... the 850CSi has 350hp.

Actually 380...plus some other interesting tidbits:

BMW 850CSi
08/1992 - 11/1996, V12 (S70), 5.6l displacement, 380 hp, number: 1510
As expected, the 850CSi makes no exception in having several names. In this case, the term M8 is mentionned on and on again. And it's correct. The 850CSi is a real M-car. It does not only have an M-bred engine (type S70, the S indicates M-origin) but has been manufactured by BMW M as well, according to the VIN which starts with WBS (BMW Motorsport) instead of WBA (BMW AG). This is mentionned in the papers as well. But although the papers say that the correct model name is BMW M8, the car has been enhanced only moderately by the M-Division, compared to the real M8, which remained a prototype only.

Here are the papers of a BMW 850CSi:


Only 1510 units of the BMW 850CSi were built from August 1992 until october 1996. Because of stricter emission guidelines from January 1997 on, the production of the 850CSi ceased as further development, because of the few cars sold, would have been too expensive. So it has the same destiny as the Aston Martin V8 Vantage. By the end of 1996, all dealers still having a CSi, were instructed to license them - and if it was for one day only - because with the new guidelines it would have been impossible to do. ↑ ↑


Specification Extras that were 'standard' in every 850CSi
Euro USA
× × Engine S70B56
× × 6-speed manual (automatic not as an option)
× × Final drive ratio 2.93:1
× Final drive oil cooler
× Engine oil cooler
× × Stiffer suspension (No electronic damping control available)
× × Chassis lowered 15mm
× × Servotronic, motorsport specific
× × Limited slip differential
× × Automatic Stability Control + Traction (ASC+T)
× × Aluminium wheels with brake ventilation
× Active rear axle kinematics, motorsport specific
× × Electric steering wheel adjustment
× Stronger brakes
× × Upgraded front and rear spoiler
× M-design door mirror
× × Dashboard with red pointers and different looks
× × 850CSi-badge
× × Folding rear seat backs and ski bag
× M-Interieur (Bicolor)
× × Leather seats
× 'BMW Motorsport' written on doorhandles
× × ///M emblem embossed in lower door frame
↑ ↑



The hydraulic four-wheel-steering
Maybe what makes the 850CSi most special was the Active Rear-Axle Kinematics system which was standard on all Euro CSis. It's abbreviation (AHK) is the abbreviation of the german expression for it (Aktive Hinterachs-Kinematik). While normal passively steering rear axles allow the wheels to be slightly turned by the forces acting on them when cornering, the hydraulics of the AHK turns in the rear wheels before those forces build up. The AHK is therefore a real for-wheel-steering system!
From a speed of about 60 kph (37 mph, BMW doesn't disclose the correct numbers) and up, a computer controlled hydraulic system steers the rear wheels depending on the turn angle of the front wheels. All four wheels then turn into the same direction, minimize weight shifts (the CSi weighing almost two tons even beats Turbo-Porsches in lane change maneouvers) and even allow steering adjustment in a curve to an extent that would inevitably cause you to crash in any other car. According to various sources the maximum angle the rear wheels turn is between 1.5 and 2.5 degrees (again, BMW doesn't tell).

With the introduction of the CSi the Active Rear-Axle Kinematic was also on the option list for the normal 8 series. But the additional amount of money you had to pay was 6400 Euros (DEM 12500), so a non-CSi with AHK will belong to the rarest things on this planet.

Here you will find detailed technical data.

↑ ↑



--------------------------------------------------------------------------------

BMW M8
1990, V12 (S70/1), about 6.0l displacement, 550 hp, prototype, number: 1


The BMW 850CSi is a detuned version of the M8 which has never been produced and remained a prototype only. The M8 should have been built in a consequently lightweight manner in order to be a 'Ferrari-Killer'. The specially developed 550 hp engine has never been used except in the prototype - of which only one exists. But with the support of McLaren the M8 engine was transformed into the power plant of the McLaren F1 super sports car. At the time of development of the M8 there was virtually no market for such a car, so the BMW manager cancelled the project.

The M8-Prototype is perhaps the best-kept secret of BMW. Absolutely no one must see it or can get information, by order from the general manager himself. Questions from motorsport magazines remain unanswered as well. The car is locked away in the so-called Giftschrank, which could be translated as 'poison-storage'. According to BMW it is hidden behind lots of boxes anyway and will be destroyed in the near future as the 8 series doesn't exist any more and neither a successor. ↑ ↑




The Prototype has never been road safe (even the headlights were missing as you can see in the picture) and was only loosely patched together, which is the reason why it is not presented in their museum. It's not even good for that ...says BMW.

Yes, the papers of an 850CSi say, it's an M8, but that's not of much use if you know what it could have been. What the S70 engine is capable of speaks for itself. See the world record run of the McLaren F1. The guys at McLaren say they could get 1000 hp at 9500 or 10000 rpm from the engine.

The different versions of the S70 engine: S70 5576 ccm 380 hp, 24V, 850CSi 1992
S70/1 about 6000 ccm 550 hp, 48V(?), M8 prototype 1990
S70/2 6064 ccm 627 hp, 48V, McLaren F1 1993
S70/3 6064 ccm 635 hp, 48V, McLaren F1 1996

Link here, includes pics: http://www.e31.net/models.html#850CSi

[smokum]

Getting ready to do final work on my M70 heads. These are the extra heads i have M73.
http://forums.bimmerforums.com/forum/showthread.php?t=1345932

[Robbie1490]

You can have my 750il, along with the engine.. I'm sure someone could fix the lifters or the head.. No one around here will work on it, so im selling it soon. Just take the engine out :P

[smokum]

Are you planning on making headers? what is your background?

As we all know there is an art and science to good header design. Thats not even addressing the welding challenges.
Im not a good enough welder to make headers i would have them either custom made to an engine stand or custom made for the E31 what id like to know is if they would also fit the 7.
The exhaust port shape has to be changed in order to get them gases flowing, that is what i have found out.
If you guys can find me a company that has welded up some M70 headers before please let me know, i have a local header shop but i know it would cost less for a premade jig.

[smokum]

Got heads back from Terry Tinney Performance motors,
Sizeing up M73 valve train. oops 3rd one is upside down
BTW
If anyone has extra M70 parts let me know

[John in DC]

Maybe..... the 850CSi has 350hp. I would think that they would have at least a DOHC. But they don't. If the heads are diffrent I wonder if they would firt on my 91?? That would just be to easy. Has anyone heard or has seen a twin turbo or supercharger for the V12?

Kindly forgive the shameless self-promotion. :-)

Yes, I have heard and seen both twin turbo and superchargers for the V12.
.
Click Here for M70 Twin Turbo Details (http://forums.roadfly.com/forums/bmw/bmw-8-series-e31/5870543-1.html)
.
Click Here for M70 Supercharger Kit Details (http://forums.roadfly.com/forums/bmw/bmw-8-series-e31/9151282-1.html)
.
While I never offered the twin turbo kit commercially, the supercharger kit has been generally available for nearly one year already. Please contact me offline for details.

Rgds...

[Auraraptor]

All the cams for all the M70 and M73 cams are tame.
Here do this go get the specs for the diff cams that are made for all 3 - BMW V12's
I know they are all metric, convert them to english system then open up a summit or a jegs catalog look at the comparable cams with close to the same lift duration etc.
Youll be supprised
Id never buy the crap being sold right now id rather make my own

Cams are different...you know that, you have both heads.

You also know the exhaust port is the weak point. Proper high flow headers would be the best thing for the beast. (trust me, I spent nearly $5k and countless hours with a pair of heads too back in the day.)


Good ref on the headers, thanks...dont know how Ive never seen that before

Built to order for 1250 is pretty darn good, and the point is, with them30, theres a lot of room to grow, serious headwork, cam, etc. Easy to build up, iron block..you can overbore easily, custom pistons, etc. You can get a lot of money out of your header , which all the other mods will depend on, unless you go FI. It is not unreasonable to think that with the B35 you could go from 219 to a solid 260 or 280 without stroking it too much..with a 3.8 conversion, who knows. That includes headwork, cam, mass air converison, headers. Examine the percentage gain there and compare it to taking the M70 to 420 HP with NA mods...doesnt happen..Ive heard 360, etc. Its an awesome motor, but a single look at the cutaway of the head and you know where the issue is. Why cant take 325iS heads and monunt them and machine one backwards I dont know, its been discussed beforeWhat iron block? On the M70? Are you serious? What link had 1250 Made to order headers? I want headers so bad....

[323I Junkie]

IM sorry, I was talking about two motors at once....which I dontl know why I was , but thats me.


I do think with modern machining, we are getting much closer to being able to mount M50 heads on the things...Or at least 325iS heads, in which case there is a lot of flow work already done. It wouldnt be unreasonable to see the M70 Pick up at least 50 Crank HP or More with just 325iS heads.

The other thing I am thinking is make a reverse flow engine. You would have to lose the top end altogether. BUt then You would have center mounted turbos and everything. INtake pull off the outside..

[smokum]

Cams are different...you know that, you have both heads.

You also know the exhaust port is the weak point. Proper high flow headers would be the best thing for the beast. (trust me, I spent nearly $5k and countless hours with a pair of heads too back in the day.)

What iron block? On the M70? Are you serious? What link had 1250 Made to order headers? I want headers so bad....AURA PM me

Id like to know how far you got, if you dont mind.
And how you addresed the ex port
:D

[Auraraptor]

Smokum, nothing against you, I don't like thinking about it....it is a project that failed for me and I lost a bit of $$$$. Still bitter on it which sometimes comes out inadvertently when talking about this stuff.

[323I Junkie]

That's heavy


I think the overall results we have seen here are that the M70 is not going to happen in terms of performance. We need to look past that..

Either 325is Or M50 Heads heavily reworked

[smokum]

Smokum, nothing against you, I don't like thinking about it....it is a project that failed for me and I lost a bit of $$$$. Still bitter on it which sometimes comes out inadvertently when talking about this stuff.
I understand fully you level of frustration BUT i can Benifit from others experinces completely objective , only to learn please
PM me the story.
Theres a shortage of creative engine builders and im not team puppy i wont dis your efforts.

[Ricer Ennemi]

We all know.......the exhaust port.......

About everybody say it's :embarrasmIMMMPOSSSIBLLL:shifty
to put decent flow over theses 12 holes.I cant believe this.
Like BMW didn't though about it,or did'nt want us to.:nono
So I did some reshearch(In fact it became an obssession).
I will try to fit(yes,I'm serious)M54 heads.I read a lot so
dont tell me things I've already heard(Ex:reverse one head).

Forget about M20,M50,M52 and S5x...The M54
"fit",(I mean,give the best hope of maybe one day
be able to have a little chance of fitting) the M70.

...just gimme 15 yrs...

[spazzboy]

Good luck with that, my fellow Montrealer.

[smokum]

Man so close but so far away...I still have the extra M70 with the M73 valves and beehive springs waiting tick tok tick tok