Author Topic: M116/M117 Intake Manifolds? For Supercharger application  (Read 165 times)

greggearhead

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M116/M117 Intake Manifolds? For Supercharger application
« on: 29 September 2019, 01:55 PM »
Hello - I have a 1974 450SEL and I am looking at installing a mild supercharger setup.  I was hoping there was a fairly normal (for domestic carbed V8 engines) intake manifold I could cut and weld to build into a blower manifold.  However, the only ones I find are the two piece setup using rubber couplers.  I know this gives a good plenum volume and runner length, but - 

Anyway, does anyone know of an intake manifold for these engines that is a 1 piece design, or an aftermarket carburetor manifold? 

daantjie

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #1 on: 29 September 2019, 11:00 PM »
Don't think many of us have ventured down this path to be honest.  Maybe some of the Aussie members will chime in. "Randys01" perhaps?
Daniel
1977 450 SEL 6.9 - Astralsilber

UTn_boy

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #2 on: 29 September 2019, 11:29 PM »
With the exception of the 6.3 V-8, all Mercedes V-8 engines up through the early 1990's had the two piece plenum set up.  The 6.3 had two separate intake manifolds for the left and right side banks.  See picture below. 



Have a look at the link below.  It shows how this fella suped up a 6.3 intake manifold.  It may or may not give you some ideas. 
http://classicjaguar.com/cj/2208.html
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex
1978 450sel 6.9 Euro, Anthr/velour

Randys01

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #3 on: 04 October 2019, 02:38 AM »
yes Randy s has given this a lot of thought!!!..........and gone no where with it.!!! I have fooled around with supercharging years ago but there are new schools of thought.
Before I go any further, I am thinking about the K jetronic set up. I am not familiar enuff with D jetronic but I suspect the deal breaker with both is the miserable throttle body port in the manifold and the difficulty in boring it out. If some one was really adept with MIG/ TIG in alloy you could open her up and weld on a new mounting box. So we top mount a Rootes /positive displacment supercharger which is fed by carbys of your choice.
Something would have to reduce the volume of the existing double plenum set up.  It's too big for a positive aspiration.no big deal.
 All pretty dramatic and necessitates holes in bonnets/power bulges etc.

The other way is a belt driven centrifugal.

 The problem here is they are designed to compress only air in conjunction with a multi point injection.
As D jet is multipoint it maybe able to be adapted but now we  have  the fun and games of remapping a lot of the sensory inputs that determine fuel air ratio. I'm not sure such a range would exist in the existing D jet ECU.
Finally, modifying a road car from injection back to carby/blower might be too much for some EPA agencies?
.........I know Bentley supercharged K jet tronic.........but that's not useful when you have D!!

greggearhead

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #4 on: 04 October 2019, 06:05 AM »
I'm very familiar with forced induction on lots of different applications.  My goal is 2 fold: 1. to be able to make or modify a manifold as simply as possible, 2. to make a low profile supercharger manifold so that the hood does not have to be cut or modified. 

EFI (D-jet) vs. K-Jet - it doesn't matter.  Either one can be used with forced induction with relatively small changes, or a standalone engine management could be swapped in.  For D-jet, and extra injector controller adding fuel under boost is a simple and easy way to accomplish that, especially when we are talking small boost levels (around 6pis for example).  On K-jet, a control pressure regulator from a forced induction model that lowers control pressure with boost to increase fuel delivery is a simple way to do the same thing. 

Saying that the plenum volume is too large simply doesn't make any sense.  You size the supercharger to the volume the engine can take in, and if sized correctly, the volume moved through the supercharger and going into the engine will be correct.  The plenum volume on a forced induction engine is less important for tuning, so can be modified with less negative results, of course.  What I am now thinking of, is taking the original 2 piece manifold design, and getting rid of the plenum piece.  Capping the running openings on the bottom, and then cutting open the runners on the top to make a plenum, then boxing it in with aluminum plate and TIGing it all up.  We'll see. 

Randys01

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #5 on: 06 October 2019, 01:01 AM »
"Saying that the plenum volume is too large simply doesn't make any sense"

50 to 70 percent volume of motor displacement is a 1st principle rule of thumb for positive displacement designed supercharging in a street application.


oversize

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #6 on: 10 October 2019, 09:13 PM »
I've been working on this issue since March and there's no easy solution.  I'm putting together a prototype ATM but I'm finding one step forward leads to another issue to be addressed.  It certainly isn't a cheap venture either and hardware alone can cost more than what many of our cars are worth!  But I'm determined enough to see it through into production...

In the meantime you should have a look at these links:

http://elbe.ee/products/m117-supercharger-kit/

http://www.carobu.com/mercedes-560-engine-building

https://rennsportfactory.co.uk/product/m117-camshafts/

https://rennsportfactory.co.uk/services/

http://classicjaguar.com/cj/2208.html

And checkout 'Mercedes Benz Outlaws' on Facebook if the originality police are giving you hard time!
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

greggearhead

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Re: M116/M117 Intake Manifolds? For Supercharger application
« Reply #7 on: 11 October 2019, 07:37 AM »
Thanks for your input - much appreciated.  I think I'll just buy an extra upper manifold and start playing with it to see what is feasible and what isn't.