Mercedes V8 Inlet Manifolds

[motec 6.9]

Thanks for that

 

[Oversize]

Interesting that it seems 420 & 560 inlet gaskets are the same suggesting the ports are the same size! New M100 & M117 gaskets are on their way to compare. Parts are now arriving and the work continues....

 

[Oversize]

Obviously there’s a reason I kept all this stuff even if I didn’t know why at the time...

 

[motec 6.9]

It's called Hoarding Mark and that's the reason

 

[Oversize]

It’s not hoarding if you (eventually) use it!!!!

 

[motec 6.9]

Or as i said on faceplant if it's cool

 

[Oversize]

So they measure as follows:

6.9
Intake 45mm
Exhaust 41.5mm

117
Intake 42.5mm
Exhaust 43 x 38mm (not round)

Not as much of a difference as I expected!

 

[motec 6.9]

Very useful

 

[Oversize]

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!

I just measured the usable area of the snorkel... a piddly 67x56mm at its narrowest point!! The widest is 80mm. It was so wrong at the very start of the intake! Not accounting for any bends or excessive length, it should be a minimum 79mm round.

Not sure how I stuffed that up but probably too many calculations on a small note pad! I’ve now created a spreadsheet and formatted the formulas so I can apply it to any engines intake & exhaust.

The correct MINIMUM total ID for a 6.9 intake is 76mm & exhaust 70mm. In the old money that’s 3” intake & 2 3/4” exhaust. Taking into account the throttle shaft & plate, I think Geoff was spot on with 85mm.

 

[Oversize]

It’s no wonder the 560 dual snorkel is far better. Even a single snorkel is superior to the 450 ones.

 

[motec 6.9]

Precisely why a 560 intake assembly is going on my 6.9

 

[Styria]

Mark, I dips my hat to both of you for the work and thoughts you are putting into this. Regards Styria

 

[Oversize]

Thanks!! I think many years of research have led me along this path! You ain’t seen nothing yet!

Oh let’s not forget the 450s & 6.9s were sucking hot air! And many cold air intakes are mounted above the hot radiator!!!

 

[sean sherry]

Always a big fan of cold air intakes since reading that for every 2 degrees of ambient Air Temperature increase you lose 1 H.P. Of course with hundreds of H.P from huge V8s what is a few H.P. between friends !

 

[Oversize]

Finally people are starting to experiment to the benefit of all chasing more MB HP! Not sure if there’s enough headroom in this assembly, but I’ll see if the theory can be tested & hopefully we’ll find out for sure!

 

[Oversize]

 

[Oversize]

Minimum total ID for a 560 is:

Intake 72mm, 2.9”
Exhaust 69mm, 2.7”

Average diameter as the 560 exhaust isn’t round. Figures are rounded up.

 

[Oversize]

So basically the standard 560 TB is too small by 2mm (70 v 72mm). However, if you account for the throttle shaft and the effect of friction on airflow either side of the plate, the standard TB could be too small by as much as 10mm. Meaning that even a 560 needs an 80mm TB!

 

[motec 6.9]

Just as well i made mine 85mm then but that was because that's all you can open up chamber

 

[Oversize]

I’d imagine the 560 would be no different but I will be looking soon.