V12 Intake Swap?

[RobertK]

I've heard alot of people say that the V12 BMW engine is basically 2 M20s mated together. With that in mind I did some chart comparisons on RealOEM.com and it looks like it *might be possible.

Any of you seasoned vets know if this has been tried before? If it is possible would there be any benefits to it?

[mspiegle]

I've heard alot of people say that the V12 BMW engine is basically 2 M20s mated together. With that in mind I did some chart comparisons on RealOEM.com and it looks like it *might be possible.

Any of you seasoned vets know if this has been tried before? If it is possible would there be any benefits to it?

I was wondering about stuff like that too... there's gotta be SOMETHING from that motor that can work on ours and provide benefit. Jordan mentioned once that the heads on the V12 motor *may* be less efficient than the M20 motor... maybe in that case M20 heads could benefit the V12 motor... but who knows.

[RobertK]

http://www.realoem.com/bmw/showparts.do?model=GB81&mospid=47352&btnr=11_0949&hg=11&fg=40

Appearently it has a flange you bolt to the head before you bolt the intake on. So you would probably need both.

[2002maniac]

go for it. It would at least look cool.

[RobertK]

I've started working on finding a price for the intake manifold and flange off a 750i parts car I found online. I'll let you know more when the guy gets back.

If the price is right I'll buy it and try it.

[chuckybob]

ritalin kid, youre my swap-mod hero.

[rs4pro3]

it would even work, you'd need the p-side manifold(or the one that bolted to the passenger side head). I'm pretty sure though you'll run into interference issues with the brake booster. The M20 manifold is C shaped where as the v12 is almost straight with a little upward bend.

[rs4pro3]

I would first buy just 1 of the 2 gaskets and see if the bolt pattern and ports line up first.

[RobertK]

I don't think it would be to terribly bad. I was thinking more along the lines of using the driver's side intake manifold.

Anyone on the boards have a V12 7 or 8 Series that can do some measuring?

go for it. It would at least look cool.

I plan on getting my car dyno'd as it is in stock form now before I actually start doing any performance type mods. That way, if the V12 intake mod does work, I can alteast find out if it's worth the trouble.

Another thing to consider this that since the V12 intake is kind of like a log intake it make be even better for those looking to use FI.

[rs4pro3]

I believe the flange rotation is wrong on the driver's side intake manifold. Remember on the v12 the intake side is on the inner side of each head, so the head most like our m20's is the passenger side head.

[rs4pro3]

Here is a picture of the Passenger side head's intake


If you notice the ports and mounting is completly different then the m20's



Plus you'll have the oil drain from the head to deal with that the V12 dosn't use.

[RobertK]

Here is a picture of the Passenger side head's intake


If you notice the ports and mounting is completly different then the m20's



Plus you'll have the oil drain from the head to deal with that the V12 dosn't use.

Of course there is a flange that goes between the head and the intake manifold. If the driver's side intake goes to the passenger with the flange angled upwards then would you not still use the driver's side intake and flange?

Nice Pics BTW.. do you have any of the flange?

[rs4pro3]

http://bmwe32.masscom.net/sean750/V1...ughIdleFix.htm

That site has some good pics of the intakes and how to replace the gaskets.

[rs4pro3]

the rotation on the last 2 cylinder is the oposite direction, or else possible the v12 intake could bolt right to the head without the gasket plate.

[rs4pro3]

few more pics


Supprisiling v12 rebuilds have actualy been pretty well documented on the internet.