Corvette V12 Project...

Richard454

Well-known member
Joined
May 6, 2008
Messages
153
Location
Atlanta, GA
OK- some may flame (NCRS-HAHAHAHA)- some think it's cool-others can't figure out why the hell I can't just put a Chevy engine back in it-

Engine- 5.0l (OK -I'll convert it to CI 304) BMW V12 All aluminum SOHC from a 1990 BMW 750IL
About 300HP as found in the car- I plan on cleaning it up-pulling all the accessories-no cats- so I'm looking at about 350HP. Motor weighs in right around 500lbs fully dressed (for my car).

Going to run the stock fuel injection-but probably run one fuel pump instead of two that were originally used.

Going to have to dry sump it- has a front sump- but this is relatively easy to do and has been done many times before.

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Motor mounts are done- motor sits right where I want it- Made some mounts to fit the stock Chevy motor mounts. NO frame mods needed at ALL!!! Stock SMALL Block hood will fit (however I have a L88).

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Drive by wire system (this was the first car in the world w/ this system) I already have it wired out-Before I pulled the motor I made sure everything would work as i cut each wire.

Electronic throttle-
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Going in the car...
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It fits- w/ no real issues-

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What do you think?
 
Cool. I like it.

How does the length of the engine compare to a V8? What will you be using for a transmission?
 
I spend a lot of time over on LS1tech in the conversions section and there has to be at least 4 LS1-into-bimmer swaps in progress with another 4 or so complete. I like the fact that this is somewhat of a reverse! Definately keep the pics coming. My only real concern is the power. Only 350 for a V12? I feel you can improve on that :devil:
 
The engine is 29½' long- so about an inch SHORTER than a BBC w/ Short W/P.

The transmission that came on the car is a 4sp auto
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The bellhousing is removable-so I can mod to fit a Tremec (500 or 56). It's been done. A lot of the Lambo Kit car guys have it modded to fit a Porsche Trans axle. OR I could get a 6-speed from an BMW 850-will bolt right up -but a little more expensive. Looking for a deal...Not decided yet.
 
Sweet a Bimmer dry sump motor :)

It looks 100x better than that Jag V12 conversion I saw once. This is going to be sweet.
 
What a cool project. Not enough o's in smoooooth to describe a bmw v-12...
 
Very cool project, looking forward to watching it!! How are the electronics going to be adapted? Are you using everything out of the donor vehicle??
 
Thanks guys-

It's funny some people can't figure out why I am doing the swap- "Why don't you just put the original engine back in it?"

It's a 1971 -CHROME bumper car-that I bought my senior year of High School in 1980. The original motor was long gone (LS-5)- I'm sure it was blown up-by the fiberglass repair I had to do in the storage compartments when the PO broke the half shafts. The car had rear flairs (which I have kept ) and a 4 point rollbar when I bought it.

The Jag conversion- sticks out of the hood way too far-394P8190014-med.jpg

Unfortunately the BMW V12 has some limitations due to the heads- they were designed to move a 4400lb car down the road effortlessly -no drama but respectively fast- the 850 2 dr at 4200lbs puts down a mid 6 sec 0-60. Again it's only 305 ci- the cam is really mild and it still will put out 1HP/CI NET rating. BUT back in the day the LS-5 454ci only put out like 270HP NET and weighed almost 200lbs more. SO- I think I'm going to be happy w/ the performance. And if not -there's always a turbo-which I have seen this engines put out some nice numbers under pressure.

Gene- the exhaust...I was thinking sidepipes- When I had the car painted I got the filler panel on the rear. Right now there the factory manifold run 3 cyl to one- then in the BMW ran into two cats then into a resonator and a big ass muffler. When I was wiring/testing the car- I cut off the muffler-Sounded great w/o it. That's my next step... Exhaust system...

As far as the electronics- thanks to the guys putting these in Lambo kit cars- reusing the stock electronics made the most sense and very cost effective. The drive by wire?

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BMW was the first to come out w/ it. Unlike Toyota- if something goes wrong- the engine goes in to Limp home mode and just runs one bank of 6 cylinders. In fact GM used a BMW V12 in an Impala to study it's drive by wire design-
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Six wires to the factory throttle and I'm there. The engine harness I will just clean up- Going to mount the computers in the BMW's stock metal box- Which has it's own temp sensor and will switch a self contained fan on if needed- right where the Corvette's overflow res was. The original harness has two 20 pin connectors that disconnect the engine/electronics from the car- I was able to cut the wires/ identify and make sure the car ran w/o BEFORE I pulled the motor out.

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I'm working on the cooling system tonight- I have the Dewitts rad w/ twin fans- Plenty of room -could even run a mech fan.
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And looks like I've found a place for the BMW expansion tank-up high- and will do a good job bleeding the air out of the system-

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These Germans really document their stuff....

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Richard
 
Looks like the electronics to operate the throttle could be used on the dyno i'm trying to digitize. Is that an arm mounted to the motor ? Do you know what type of electric motor it is ( servo/stepper) ? And what type of E is this BMW you got this ETC out of ? BMW parts are plenty around here so this may be the easy way out for me.

Thanks for the info.

Succes with the conversion. Although I wouldn't have done it, I can appreciate the mechanical effort you made to make it work. Being a V12, I can imagine it must be fine running engine. (Wasn't that a 2 valve engine ?)
 
The electronics to the "drive by wire" are part of the total engine management system. There is one computer for each 6cyl bank and a third that syncs them. The electronic pedal or rheostat -which I pulled out and directly wired underhood- talks to the sync computer which then sends a signal to the two computers w/ turn the electric motors (one for each bank).

It is a 2 valve but a SOHC design driven by a chain not a belt. Actually the bottom end on this motor was used in the McLaren FI w/ 4valve heads.

Vision? Most of the time I have "double vision!!!"

This is one for the "It should be a Chevy engine crowd...."

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