That's an impressive piece of engineering right there

I'm beginning to think that the only way to insure perfect distribution is to plumb the throttle body entrance into the valley side of the plenum so that the air charge hits the roof of the plenum and then gets directed equally amongst the runners.

 

Here's all it took to get equal flow to each runner when simply using a shop blow gun and blowing air into a fully opened throttle body with the complete intake assembly sitting on the bench.

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Not the prettiest thing in the world but I think this design would be best for air distribution.

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I like it. That's like what was used on the Indy Chevrolet engine.
I would carry the inlet tube that enters the plenum higher into the plenum.

 

I had to see what you were talking about, I found this pic and you're right . I'm not a big Indy guy, I'm assuming these engines were turbocharged?
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Yes. It was turbocharged. Check out the Cosworth V8. Also turbocharged. It also had a similar intake design.
Bellmouth and round the edge of the inlet tube inside the plenum.

 

I am by no means an expert or engineer, but I love this thread. I like the idea of the charge pipe coming in from the underside, but wouldn't there need to be some small dams on the roof of the plenum (between the first and second pair of cylinders and between the third and fourth) to keep the charge from traveling mostly to the frontmost and rearmost cylinders? I may be wrong in thinking of it this way, but with it being forced induction I was thinking the air would spread across the top of the plenum much like water splattering on a flat surface. Keep up the awesome posts.

 

Why does the inlet tube have to be round entering the plenum? Why not have the tube run straight and flat along the bottom of the plenum with a long slot where the tube joins with the bottom of the plenum, and have the inlet be a long thin slot along the bottom of the plenum? Nothing protruding up into the plenum.

 

The nice thing about having the air introduced into the plenum along the bottom side is that it frees up the roof of the plenum for all kinds of creativity.
Notice on the Chevy Indy V8, all the fueling is fed into the mouth of each intake runner. Two injectors per runner. The fuel rails to feed the injectors are incorporated into the roof of the plenum.
Don't have room to fit all your fueling needs onto the intake runners? There's plenty of room on the roof of the plenum.
My next engine configuration will be needing, per intake runner, 2 electronic injectors, one mechanical fuel nozzle, and one wet nitrous nozzle. A clear plenum roof that is free to be configured any way that is needed opens up a wide range of configuration possibilities for arranging the fueling system.

 

Couldn't one also run a sandwich plate of sorts much like RJC had been doing with the turbo buicks for years to eliminate the leaner rear cylinders?

something like so...

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http://rjcracing.com/product/airflow-distribution-plate/

 

A plate like that is a band-aid for a manifold design that has serious distrubution problems.
The idea is to come up with a design that doesn't force a person to resort to such drastic fixes.

 

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Thought this was relevant...its from the "fopar" build thread. Its a hogan manifold.

 

http://image.mustang50magazine.com/...cougar_cobra_hybrid hogan_racing_manifold.jpg

Another

 

The design in my mind would work well as it is similar to the Ford GT-40 Intake used on the Mustang where the inlet is on one side and the air bounces off a flat wall and evenly feeds the intake Runners on either side of the inlet opening.
http://compare.ebay.com/like/280857982818

Tom Vaught

 

Man, I had no idea this thread existed! Good info in here. I built two manifolds for my Big block Mopar about 2 years ago, and there were no real good offerings for intake runner material to make a tapered runner.. In light of this, I made my own die and mold to make a tapered runner with 1 welded seam. Here's the end result:





Here's what the transition looks like:


I machined a recess in the plate that bolts to the head so it would be easier to weld. The end of the runner slips right into it and you weld around the outside. Makes for a smooth transition into the port. I'll need to put a bit of epoxy in there to fill the slight voids, but it will be a skim coat.



Here's a pic of the die and mold.

 

You do good work . I ran across your build thread when you were making your first intake manifold and that's what inspired me to build my own (and go with a 4L80E)

 

Yes, a very good thread.

Food for thought, ALKYV6, I saw a V-6 Intake Manifold (designed for boost)
that had three 3.575" diameter (throttle blade) Throttle Bodies built into the upper part of the runners. A 1/2 moon scalloped divided separated each pair of runners. The large 3.575 blade actually traveled partially inside the runners. A round bellmouth entry was slightly above the upper edge of the butterfly valve.

All of this valving was inside a rectangular Box type Plenum that was fed boosted air.

Intake was made by a fab shop called Technosports in Michigan.

Tom Vaught

 

Sweet! Glad I could be of service and inspiration!

 

I can't get a picture of that in my head. I'd have to see a picture or drawing. Do you possibly have a link?

 

My engine is down for a change in heads. This will require all new intake and exhaust manifolding.
I've started work on the intake. It will be a bolt together design.

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