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Engine in shop, manifold in the works

5K views 40 replies 16 participants last post by  KRH 
#1 ·
Just received my winter project, the plan is to design and fabricate an aluminum sheet metal intake manifold that will allow the swapping of the bosch cis to a modern efi system .

We will see how it goes worst case scenario I have a spare motor , best case more power ,reliability and some good old fashion fabricating fun .
 

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#2 · (Edited)
Man, I am speechless ... Don't know what to admire first: the shop, the motor or your dream ... For sure all together, but is hard to figure out which one to begin with ...

Anyway, glad you start this project. I'll take a front row seat and put some popcorn in the microwave to enjoy the show. I can hardly wait to see it started. Too bad we are not in the same area, I'd stop by in the evenings to admire your work, chat about it and talk about your future plans.

Good luck, I'll be watching the developments with great interest.
 
#6 ·
Too bad we are not in the same area, I'd stop by in the evenings to admire your work, chat about it and talk about your future plans.

Good luck, I'll be watching the developments with great interest.
I to wish you did live near by I could use a set of real engineer eyes on this , this is a as time allows hopefully no stress project that I am looking forward to . I like cars ,machining parts and solving problems so this project has a bit of each .

I will post along the way , here are some more shop pics.
 

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#3 ·
cool...i hope to learn something from this

have u discussed this with andy at elbe engineering who have their efi, or mike at dkubus
 
#10 ·
Just so many levels of wow. I am drooling over the shop of course. It looks like you spent years getting that right. As to the intake, it seems like this is one area Mercedes screwed upon the engine. That is very underpowered and a lot of it is the air intake flow. Good luck on solving it. Keep us informed please.
 
#11 ·
Between the dual fuel pumps, 1970's FI design, and parts availability, I'd be happy to dump a Holly carburetor onto my engine much less a more modern EFI!! Good luck with this project.

A friend of mine, Dick Spellman, has a 5.0L engine that he's having overhauled in the Boston area. I'll PM you his contact information and you can ask him for the contact info on his mechanic. I get the impression that mechanic is quite good on our cars and could be a good pair of eyes to help with your project.
 
#15 ·
Rich the main issue is in the factory plenum design where it is just not deep enough.


To convert to carb it would be simple for you as you have already machined the face plates
To help you with ideas here is a good example of what is needed to convert to carb in the below pic

But even better is this custom intake for mutliple side draft t/bodies and it works a treat on that engine whilst still retaining hood clearance and not hard to do but would require a modern ECU and tuning
 

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#20 ·

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#22 ·
Thanks for all the great responses, for the record my name is Scott Richter. You can call me Rich but my accountant may disagree.

The manifold design that i am attempting to make is going to be a long as possible runner efi manifold in the modern ls engine vein.

I actually want to lower the peak torque rpm and fatten and flatten the mid range torque curve while allowing a modern efi and ignition system to be installed. Basically i am attempting a ls swap while keeping the m117 motor.

The controller will be Holley most of the sensors , coils and triggers will be GM , if I possessed tuning skills i would use a GM ecu but This dog is to old for that trick.
 
#23 ·
I will post up the pics of my EFI kitted 560 engine (300 hp engine used as the base engine) if that is of any use for ideas
It runs with a modified dizzi for 3 wire hall effect
Aftermarket throttle body
D-Jet injectors which work a treat
Custom fuel rail which is easy as the injectors are connected by flexible fuel hose as they did back in the day, but it is keeping with the retro look to try and look like it was factory
That is run by Haltech 2000 ECU which is more than adequate for this engines needs using the factory coil which is also very adequate, but you have the ability for individual coil packs (GM) if desired but not necessary for street unless forced induction application

The main issue is still the intake manifold that was not modified
This is the biggest challenge in a M117 to come up with practicable solution to improve the plenum chamber - as to the top manifold - that is fine in design to retain low end torque
However to allow any room for a increased plenum chamber size it requires the top intake to actually sit higher.
To enable that to sit higher it requires modification on the face plates as you are doing from scratch with new ones.
It could be achieved by cutting off the factory face plates and working with the rest of the top intake married up to new face plates to create more height as the runners are well designed and no need to re-invent the wheel.

Looking forward to your progress Scott
 
#25 · (Edited)
Interesting thread!

Im actually working on the exact same project, but started working on exhaust manifolds first, and slowly working my way to the intake setup. Im sure we can share info back and forth.
I have a spare M117 that im using for my mockup, and to help you with mock-up, check out the header fab mockup kit I designed, it can easily be used for layout of intake plenums as well, and help you on this journey. My pic below is old, I have it nearly all mocked and slowly ordering material.

My setup will be a bit different as your, assuming your planning to keep your engine NA, im adding a supercharger so my intake setup will potentially be different depending if I go with a vortech or whipple style SC.


Idealy I would like to get a mockup LSX/LS7 intake manifold and see how it physically fits between the heads. Who knows, maybe CNC some intake adaptors will allow me to fit a pre-fabbed whipple LS7 supercharger? who knows, that's the fun in veering off the beaten path.

https://www.thingiverse.com/thing:2053049
 

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#32 ·
Very nice set-up and I'm sure not cheap by the time you add the EFI kit (I'm thinking $10k), I am willing to spend the $$ and buy this for my car but would like to see the entire kit up and running on a shop car before I commit. I'm not a fan of being serial number 00001.
 
#33 ·
Same here, I really do like the design and layout of the Neviu's intake supercharger setup. its exactly what I would like. Ive been test fitting with a mockup vortech V-3 SI, but from what ive tested so far im not happy with the overall fitment and location options. I wonder if the Mangnason is a off the shelf part? would it be more cost effective to order the intake setup from Neviu in europe, and source the Magnason locally in north America?

I would be the first to sign up and order Neviu's setup as well. And by no means do I mean any disrespect at all!. But my situation is a bit different, it IMO would be sacrilegious to my cnc equipment if I don't build something myself vs buying a premade kit, especially something in this price range. Who knows maybe at some point ill throw in the towel and order his intake :thumbsup:
 
#28 ·
Carobu engineering went with an old M116 70's intake manifold in their build which was a step backwards in my opinion and they had to highly modify it to bolt up to an M117 , but it allowed them to increase the plenum chamber depth on that set-up without increasing the height of the top intake.

The M117 560 intake runners are very well designed for street torque band and will also flow at high revs with a bit of minor tweeking so the top intake is not the issue.
It is the bottom plenum that is the issue - it is too small

It cannot be just increased in height or width for extra volume as there is simply no room in the valley for it to be done.

The 560 plenum sits tight in the valley with only about 4mm gap to the floor/wall so the only way to increase height is to go up, however the way the plenum connects to the top intake via the doughnut seals there is simply no available metal to sacrifice (cut back) say 1/2inch to increase plenum wall height. It is just not possible.
It requires the top intake to be lifted up by 1/2" or preferably 3/4" and to do that requires re-designed mounting face plates that actually create more height to the intake almost like putting spacers to face plates that create more lift

If Scott could work on that process it would mean retaining the 560 intake with a deeper plenum (more volume) with its wall height increased by min 1/2" (preferably 3/4") and allow better flow from the T/Body plate to the intake runners.
It would be the most cost effective way for a naturally aspirated 560 and also retain the factory look if desired when opening the hood.

Coming up with a newly designed intake/plenum in lightweight modern composite material would be nice but also very expensive unless you modified one off the shelf from a GM LS or ford Coyote 5ltre to fit by chopping off the face plates and bonding them to a machined alloy face plate exactly like Scott has machined up
That would be the only logical path i can see to make it doable without costing a small fortune but probably not an easy exercise as modifying an existing 560 intake
 
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