Intake Manifold Design

I like that design a lot. I would say the distribution would be very close on all cylinders.
 
The fact the head doesn't have true ports even with the intake shaved off still is the biggest disadvantage of anything for making a "tuned intake". Redesign a head or keep punching yourself in the balls.
 
To anyone interested in fluid mechanics and gas dynamic textbooks for nothin'.
http://www.potto.org/

I agree with Seeker, but I also agree with Child9. Putting something into practice is the root to observing the quirks. However, the point that we as humans are in in terms of technology and understanding how things react among different states. I believe it was JFK whom said this, much has been gven to us, therefore much is expected of us. The farmer's cut and try is and will be here forever. The present time we live, technology that can be used should be used. Hamilton used CAD or Solid works like many other industry personel, others would do that same if they could. Others like myself use paper pencil and 3d perspective.

Joe, that manifold looks like its in quite a tight spot on the I6s. Interesting piece. Being much larger, the stock intake box can what supply to what 5000, maybe? The CCs should be enough to feed it to a higher rpm if you take in the simple larger has more capability of providing enough. However going too larger on a plenum has been said to not do much at all once a certain point has been reached in capacity.

Scat, whats your view?

Child9 wrote:
Waves in a system exist independently of air flow and are caused by the rapid pressure pulses caused by the valves opening and closing, so regardless of how we get air into the cylinders, the waves are still there. Charge air crashes into the valve and a compression wave bounces back and up the runner, just as air does in an NA application.

A waves velocity is not related to pressure, so higher pressure waves do not travel faster than lower pressure waves. The velocity changes with respect to temperature.
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Hmmm, when we employ tapers have you seen any changes on the wave's nature of maybe the speed of the reflection opposed to the non tapered runner opening? Do you have any good acoustics links you could post?
 
No real change we should be concerned about.

I wanted to cite that statement with a source and found this first on wikipedia...(because wikipedia is statistically far more accurate than the general public gives it credit for. :) :
Cones
An open conical tube, that is, one in the shape of a frustum of a cone with both ends open, will have resonant frequencies approximately equal to those of an open cylindrical pipe of the same length.
The resonant frequencies of a stopped conical tube — a complete cone or frustum with one end closed — satisfy a more complicated condition. [EDITED] In words, a complete conical pipe behaves approximately like an open cylindrical pipe of the same length, and to first order the behavior does not change if the complete cone is replaced by a closed frustum of that cone.
 
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It should be noted that there will be two resonant frequencies of the manifold...one from runner length and one from plenum volume. Once the tools are properly understood and their implementation arbitrary, it is possible then to stack the harmonics for a torque peak or spread them out for a flatter but higher overall curve (than untuned or improperly tuned). The manifold should be tuned for its specific application.

Fahlin: Thanks for the book.

-Chad
 
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and if you introduce a damper between the two like an intercooler core.......everythign changes
 
The importance of dyno tuning to dial in the resonance tuning is pointed out by Seeker...though again I wouldn't focus too much on resonance for a street application. Good CFM and cylinder balance should be top priorities.
 
renopker said:
A big open plenum I cant understand how the air could even find its way to the valve.
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:thankyou2: My theory is there was an information booth located in the inlet piping. From there, the O2, N2, N2O, AR, etc, picked up brochures, logged onto their forum and debated whether to go back to the turbo or forward to through the valve. While there, they whined and complained that some of the molecules weren't following 3rd order resonance.

child9 said:
Do we get to ask several yes/no questions? :) What was that game show? I've Got A Secret?

1.) Is the total manifold volume (manifold plenum + 5 runners) approximately 545 in^3?
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Really close, I can't find my paper with the volume calc. I had to shape the front shorter to fit under the hood and I couldn't go wider because the ppump was in the way. 6 runners BTW.
 
joefarmer said:
6 runners BTW.
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Yes. The 5 other runners that all go to closed intake valves are considered part of the plenum volume at that point, since all they are doing is contributing to the plenum volume while the wave action we are concerned with is moving through the 6th runner with the open intake valve.
 
child9 said:
Yes. The 5 other runners that all go to closed intake valves are considered part of the plenum volume at that point, since all they are doing is contributing to the plenum volume while the wave action we are concerned with is moving through the 6th runner with the open intake valve.
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Thanks! I never thought of it that way. I guess I was never really concerned about figuring out the wave action as long as it worked reasonably well and held together. It had problems with bowing out until the 1/4" through pins were replaced with 3/8" solid pins.
 
joefarmer said:
Thanks! I never thought of it that way. I guess I was never really concerned about figuring out the wave action as long as it worked reasonably well and held together. It had problems with bowing out until the 1/4" through pins were replaced with 3/8" solid pins.
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What boost level were you running and what was the material thickness of the walls?
 
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Doing some basic calculations on rpm related.

If we run a 5.9L at 6,000 we ideally need 625cfm of flow, we need a reservior holding around 360 + or - IMO. If we roll with 40psi we end up with 125lbs of air ingested.

At 6,000 rpms we have as follows:
1,500 Intake pulses per cylinder per minute.
1.500 exhaust pulses per minute per cylinder
1,500 exhausting pulls on the intake charge per minute per cylinder (valve overlap)

Depending on our VE, will show us how much we are using actually and we can see what route needs to be taken. Too large I believe we will create a lag in cylinder fill and too small we may just 'suffocate' it theoretically speaking.

:pop:
 
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Fallin - to be realistic - most 5.9s never see the high side of 5200 rpm give or take, and from what I have seen in video and in person, most pull trucks for sure run somewhere between 4000 and 4800 rpm down the track.
Might you redo your calcs for a working range of something around say - 4800 rpm or so?
 
So we are only looking at what most people see max rpm. What rpm does John Robinson's Cummins spin in that funny car, would anyone here know that?

I wonder how much rpm this crank has seen or can go I wonder?
http://www.competitiondiesel.com/forums/showthread.php?t=109776

So if we have 1,200 intake pulses as CHild9 posts, how would you Seeker and you Renopker go about plenum size & shape? Perhaps a square or ovaled, maybe a hexagon? Anyone looked at what shapes promote certain attitbutes of the flow? If we leave the pump in its space on the factory 5.9 CUmmins we have around what 3 - 4 inches until we hit the pump that leaves one odd shape around the pump allowing a quicker movement of air into the runner and to the cylinder so would this be a decider in supplying the rest of the cylinders?

Whats anyone's view on transition from a pressure energy to a kinetic energy cylinder fill?
 
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