Mercedes V8 Inlet Manifolds

[c107]

These guys are doing some interesting stuff on a 560 ATM:

http://www.carobu.com/

See this thread:
http://www.topklasse.org/forums/showthread.php?t=6987

 

[Oversize]

Damn I forgot about that thread sorry! At least it now ties it all together!!

 

[Oversize]

I was prepared to persevere with K(E) Jet with the help of Dkubus, but the size of the mechanicals leaves stuff all room for the most important factor being air flow. You can do what you like to other aspects of these engines but until you address this issue any performance upgrades will result in minimal gains per dollar spent.

 

[motec 6.9]

Will see what I can come up with on my car soon I'm hoping. Coming to an end my legal dealings over car accident.

 

[Oversize]

My fabricators at the ready awaiting final mock up.

 

[c107]

How does a 6.9 (or even a 450) even breathe through this thing??? It’s now been proven the stock air filter housing restricts flow into the air flow meter. And that’s just the start!

At least on the 560, the carbou guys seem to think the intake and air flow meter was the main restriction point and the air filter was fine. the 560 is dual snorkel though.

I suspect if you open up the intake/air metering then the air filter unit starts to become more of a problem.

 

[Oversize]

They found the bulge to clear the fuel divider was restricting flow along with the lack of headroom into the air flap. However the restrictions aren’t as much as the 180deg turn at the bottom of the plenum.

 

[Oversize]

The air filter design loss is as much as 10hp!!

 

[motec 6.9]

I will be fitting the 85mm throttle body and FrankenCIS to my 6.9 once I get it back. I may see about adding volume to the plenum plus thanks to Michel I have a 560 Air cleaner .

 

[Oversize]

I love the machine work on those TBs Geoff!

 

[motec 6.9]

Have 3 so once I have proof of concept I may let others go

 

[Oversize]

So in my spare time (very rare lately) I like to read:

http://docsdrive.com/pdfs/ansinet/jas/2012/161-167.pdf

If my calculations are correct (along with the formulas) a 6.9 has an ideal port size of 30mm at 700RPM & 68mm at 5500RPM! Pretty outrageous considering the throttle supplying the WHOLE engine is only 70mm!!!

 

[motec 6.9]

Actually 6.9 is 65mm but yes 560 is 70mm I had one of those as well.

 

[Oversize]

65mm is just laughable for such a big engine!

 

[motec 6.9]

Yes why 85mm but also because going above will not leave enough meat in manifold to bolt holes.

 

[Oversize]

Which prompted my current project...

 

[motec 6.9]

I have spare intake may see how much I can increase volume by once I get car over east

 

[Oversize]

Finally my schooling & algebra have paid off!! Lesser thanks to Google for finding the correct formula! The most difficult part was knowing the right question (a little like “there is no spoon” in The Matrix)! Now I can buy the right parts to mock up my design! Sorry for the cryptic post, but it’ll all make sense later.... Very chuffed with myself right now!!!

 

[Oversize]

Actually 6.9 is 65mm but yes 560 is 70mm I had one of those as well.

MB actually had the diameter of the 560 TB spot on, but failed to account for the turbulence & resistance created by the butterfly & shaft!

When I get the required dimensions, I’ll apply the same calculation to the 6.9.

 

[Oversize]

For future reference the inlet ports of a m117 are as follows:

500 41.0mm
560 41.35mm
500 AMG 41.50mm.

560/500 AMG valves measure 46.2mm. Obviously the valves are bigger to compensate for the resistance/turbulence created by the valve stems.