Well folks another nail in the coffin of high intake air velocity.

 Paul Lamar

 Hold on there Paul.  This is just another typical press-release mish-mash
statement.  It is the EXHAUST port area that went up 30%.   Intake port area
is not really affected.    You are so knowledgable about so many things that
it amazes me that you don't realize the key importance of intake air
velocity.

As always, I offer a $500.00 reward to anyone who can show proof that intake
air velocity is not important to intake system tuning.

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

No they are bigger too. Thats how they get the power. More air more power.
As much as 290 HP if you don't care about torque down low.

What you are missing is air resistance in a pipe is proportional to
at least the square of the velocity at low subsonic speeds and much
more than that at transonic and supersonic speeds. Many internal combustion
engines run transonic and perhaps supersonic air speeds in intake manifold

The Lemans engine had huge intake ports and in two rotor form would generate
240 HP at only 6000 RPM. A Power Sport engine with similar intake pipe lengths
but smaller dia. pipes generates 215 HP at 6000 RPM. For just a couple of
data points. The ports in modern aircooled aircraft engines are about
as large as they can be made. One reason they have good BSFC and good
power for the low RPM they run at.

This is proof enough. Send me the money.

Paul Lamar

Paul,

If you try to get a gas to flow thru a passage at greater than M=1.0 you
will get a
normal shock at the point of reaching the Mach, at the smallest cross section
area of the flow passage.  After that, any increase of delta P will NOT
increase the
flow AT ALL.  This is called sonic choking, it is CERTAIN that no air intake
system reaches supersonic speeds.  I seriously doubt that any system even
reaches M=0.7, but have not researched it to back that up.  I do guarantee
no supersonic flow, tho.

Bill Freeman

I was wrong. According to Taylor things really start to fall off around
Mach 0.45.

Paul Lamar
 
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