Intake Manifold Design

Hamilton Cams said:
Another thing to note in terms of what duration to use, for competition Cummins flat tappet cams, they range anywhere from 260-340 degrees of open time at the valve. Just having a calculated correct length will not take you very far if you start with flawed data. Also, not to pop your bubble, but all of the engineering papers I have read on the subject state that since air is like a spring, there are always resulting pressure pulses that cannot be accounted for, so all of the calculating will get you in the neighborhood and functional testing will take you the rest of the way. If you do get the pressure wave to hit the intake valve at the right RPM, it will magnify the effect if you get the valve off it's seat faster to take advantage of it..........
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This is my thinking also...wish I had the time to play with it...but cant quit the day job for at least another 30 years...

just a question, with 340 degrees of open duration, how are you eliminating flow reversion???

The cam in my KTM has no where near that...closer to 240...and that engine spins to 9k...

I know you make cams...so, you will also understand this, rocker arm ratio does not affect duration...if lift at the lobe is zero, then even 1.7 x 0 still equals zero
 
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Hamilton Cams said:
Greg, would it not be easier to just go race and back your claims, than get lawyers involved? Prove how smart you are on the track


To anybody sponsoring Greg.... Please don't allow this cancer to continue in the Diesel world! Please stop.............. I can not see it casting anybody's company in a good light to be on his car.

.......
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I would not worry about the Rhesus Monkey....he is just feeling threatened...all he can do is crap in his hand and throw it...
 
lenahan05 said:
If memory serves me, you made such a comment not long ago (on compd) about how "your" springs (common BBC spring) were better than everyone's. You started selling them and they didnt even fit the springs pockets. :hehe: ouch! I loved your explaination to the customer. It doesnt stop there.

In a race to cover up your lack of knowledge to what your even selling, you go buy a product you just previously said is junk, and sell it to the guy to make it right....did I miss anything?

Do I feel a little Manning Motorsport backpeddling coming on? Or just your typical, boring argument everyone is sick of hearing about. Taylor, ill say it for you: "you use valve locks that wont work and will cause failures, anyone who uses those sure has low standards." LOL :clap: Am i right or what?

I apologize to everyone else in this thread for the derail from greg. I wasnt going to say anything. But the sheer coincidence of it all with taylors post, I just couldnt resist. Its like playing cat and mouse.
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Who's product did i buy? Please enlighten me?

Its not a BBC spring thats for sure....

Yea i have no problems admitting we did a run of springs and the manufacturer had our OD incorrect , we have since corrected the issue already.
 
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Stingpuller said:
Fahlin you may want to do a little digging on Greg. He is all talk and NO ACTION. I have been into diesel performance from 2006. Not long compared to others but have been into performance from the early 80's. How old are you?
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I was born in the 80s lol, 27

Whatever may have happened then, its now, I just voiced what I hought should be done since everyone is heated, if you have the chance to race at Muncie then do it. If I could I would attend.

Will you go race? Drag Racing is anyone's game if you are tuned properly.
 
Diesel Freak said:
This is my thinking also...wish I had the time to play with it...but cant quit the day job for at least another 30 years...

just a question, with 340 degrees of open duration, how are you eliminating flow reversion???

The cam in my KTM has no where near that...closer to 240...and that engine spins to 9k...

I know you make cams...so, you will also understand this, rocker arm ratio does not affect duration...if lift at the lobe is zero, then even 1.7 x 0 still equals zero
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That is my question as well. I do not use 340 degrees of total open time but some do. I was just showing that so you know the potential variance. Our 200@.050" intake is in the neighborhood of 250 degrees total open time. You might surprise yourself on your ktm once you get the cam on a computer measuring machine and do the math......

The rocker arm does not affect duration. But you don't know how much open time you have until you know at what lift the lash is taken up. .020"/1.34:1=.014925" lift before lash is taken up and valve starts to move.
.020"/1.80:1=.011". lift before lash is taken up and valve starts to move.

That can be 20 degree difference on some cams and throw your math out the window.

Here is my idea of a perfect intake. Due to the V-bands in the runner, the length can be dialed in on the dyno.

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$5 fine for talking about your sword or Lawyers.........................!
 
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Hamilton Wrote:
..I have read on the subject state that since air is like a spring, there are always resulting pressure pulses that cannot be accounted for, so all of the calculating will get you in the neighborhood and functional testing will take you the rest of the way. If you do get the pressure wave to hit the intake valve at the right RPM, it will magnify the effect if you get the valve off it's seat faster to take advantage of it..........
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Getting closer I believe. We not only want the pressure wave (hopefully a high pressure) to hit the valve at the right time we NEED it to be the correct amplitude to act as a ramming effect even with forced induction.

DF wrote:
with 340 degrees of open duration, how are you eliminating flow reversion???
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The elimination of reversion would most likely take place with a higher induction pressure charge than the cylinder pressure upon IVO. However we can only limit it by raising the rpms with longer duration camshafts which provide efficient breathing a higher rpms anyhow. If you have a variable designed rocker you can "extend" the lobe duration or by floating the valve. This can be controlled by ramp rates both acceleration and decelerations. We will always have some level of charge contamination due to reversion.

Well in all honesty I would be more conserned with valve size opening duration unshrouded curtain area and a matched port cross section for this application forced induction covers up a lot of other issues to the point they dimish to the point they are not worth screwing with. Tune for the first and second order don't worry about anything after that. Or, just smooth out the port and unshrouded the head and cylinder
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Are you speaking of the entire curtain area from seat to seat or to a certain lift?
 
I guess type a little slow. Interesting intake Hamilton, it reminds me of Ford's early 302 EFI mandifold.
 
that center section sure would make a nice place for an ice cold air to water intercooler Zach, looking good!
 
mikmaze said:
that center section sure would make a nice place for an ice cold air to water intercooler Zach, looking good!
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That's what I was thinking, since I'm rounding up parts for a intercooler of that nature right now. Slightly milder though, 180cfm head with the stock intake shelf.
 
Looks like you'd have plenty of room to hang an atmospheric turbo under each of those. You could run a set of "twins" with 4 turbos.....
Looks very cool!
 
Thank you, Sir.

I had thought about that, but then there is the equation about horsepower and mass. I know about a certain rail that has what looks like an extra 1k on tap but can't use it due to traction issues from too much mass. Mass is a Mother...... EFR chargers are really low mass, but they do not operate at the same pressure ratios as compounds, so head and intercooler are very important.

Another thing to add is that when calculating for runner length for the second, third or fourth wave , calculate from the center of the valve stem, not from start of the runner at the edge of the head.



Do one of you Poo, Lawyer or Phallic types have anything intelligent to add to the discussion besides poo, lawyers or phallic symbols? :)
 
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Zach - you will remember when i emailed you a three weeks ago for valve events and you were quite surprised as no one asks for that stuff - your modelled intake design is almost identical to what i currently have under construction, except mine has tandem intercoolers to get more length so the runners dont have to be leaned in towards each other. Each intercooler handles 3 ports with an integrated plenum, on my setup
Your runner length as shown may be slightly short even for 4th wave, depending on what cam you are using

my setup will deal with reversion, as much as is possible, as well.

pretty cool twin turbo setup for sure - mine being only single charger

your version does sit a little too high for decent packaging purposes in a truck, though it would work on a rail quite well
 
http://www.phys.unsw.edu.au/jw/Helmholtz.html

Just some information to add into the mix.
Rarefaction wave - is the reduction of a medium's density and is opposite of compression.

I have been informed that a common rarefaction wave is the area of low pressure (relative) following a shock wave, rarefaction waves expand with time.

I don't believe this has to be tweaked since forced induction is just a higher pressure situation.
Mean Inlet Gas Velocity

V(m/s) = (LxN)/30000x(D/d)^2
L= Piston stroke
N = Engine Speed
D = Bore of Cylnder
d = Port or valve throat diameter

I know its a very basic situation but it gives something to work with until more indepth detailed analysis is gone through. For when th bowl and throat area is being thought of when designing. For those whom don't know the definition of a Venturi.

[ame="http://en.wikipedia.org/wiki/Venturi_effect"]Venturi effect - Wikipedia, the free encyclopedia[/ame]

If e are charging the bowl with all this pressure, we need a good venturi to allow correct acceleration and deceleration rates to fill the cylinder without hitting choked flow, turbulence or choked flow because of turbulence. Since forced indction amplifies vorticies, we must test from the plenum to the valve divergent area. Reminder air takes th shortest distance regardless of pressure distribution within the runner, it will change its position of the peak of flow to get there in the most efficient manner.
 
9724VF350 said:
That's what I was thinking, since I'm rounding up parts for a intercooler of that nature right now. Slightly milder though, 180cfm head with the stock intake shelf.
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finally someone posts a realistic flow number. its been a while since i seen a real believeable number. a 180cfm stock shelf head sounds like your heading in the right direction IMO. hope it works out for ya.
 
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