Intake Header

[NavySEAL2B at insightbb.com (GTG)]

You mean like tuning the length of the intake runners?  Because yes, that 
does help, similar to scavenging as you've said.  Do you have some sort of 
design in mind?  If you're interested in making a really good intake system 
without doing any ridiculous physics, look at existing designs.  First 
things that come to mind for me (I'm a Bimmer guy) are the Euro S50 engine, 
S14 (esp the Carbon manis for their race cars), and Dinan Z8 intake systems.

Some reading material:
http://www.google.com/search?hl=en&lr=&c2coff=1&q=helmholtz+equation+intake+manifold&btnG=Search
Vortex also has several threads having to do with the helmholtz principle 
and intake systems.
I skimmed through the first few links there and they look pretty useful. 
I'm working with wave physics right now in school, and most of the math is 
barely beyond the level of a good college level physics 1 course.  Waves and 
fluid dynamics are responsible for the "scavenging" effect you're looking 
for.  The scavenging comes from waves, though, which only produce the right 
effect at or very near certain frequencies, which is why it will be most 
effective in a narrow RPM band.  Some more modern engines have variable 
length intake runners (along with the variable valves and such) to optimize 
for several different RPMs.
I've also heard that polishing the inside of intake runners is not a good 
idea because a rough surface actually creates better flow.  I suppose that 
doesn't include the area right up at the valves since polishing is so 
popular there, but that might be something to look into as well.

-Grant-
Annapolis, MD/Louisville, KY
1980 in storage :(



----- Original Message ----- 
From: "Kervin Ridgley" <carsandkites@gmail.com>
To: <scirocco-l@scirocco.org>
Sent: Tuesday, November 30, 2004 12:04 PM
Subject: Intake Header


>I was thinking about ways to get the the intake side to flow better.
> Would something like a intake header help.  By spacing out the intake
> sucks (you know, the opposite of exhaust pulses), would it "scavenge"
> more air in?  Just a crazy idea I was having.
>
> Kervin
>
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