Everett Hatch was not entirely infallible. Look at his incorrect position
on the torsional vibration issue. Neither is Jim Mederer.
Compared to the engineering resources of Mazda they are fleas on
the back of an elephant.

It always amazes me how people are in complete denial on the Lemans
engine. It is a big mystery to me. Do you think Mazda was lying
about 240 HP at 6000 RPM? Do you think the drawing Mazda published
in the SAE paper showing the P-port to be at least two inches in diameter
to be a cartoon? Have you read what I wrote and looked at all the pictures
of the Lemans engine? Do you not believe that the 3rd gen ports are larger
than the 2nd gen ports and that the RX8 ports are larger than the 3rd gen
ports by 20%? Do you not believe the bigger the pipe the more the flow
at the same velocity? What's up? I don't get it. Am I to be completely
discounted? Are you people being contrary just be contrary and create
a controversy? :-) As my wife is found of saying; "what does logic and
reason have to do with it"?

I'll tell you what is probably fooling more than one  cottage industry
rotary engine tuner. And that is this. The diameter of the pipe also affects
the tuned length. Surprise! Have you been to church lately and seen an organ?
If you are not trying all combinations of pipe
length and diameter on your dyno you are fooling yourself. See
the chart below. Lets say you want to try only 3 different diameters
and 3 different pipe lengths and 3 different timings. That is 27 different
combinations and dyno runs. Did Everett or Jim do this? I don't think
so. OK lets say you make three different pipe diameter variable length tuned
intake manifolds. Or start small and tear the engine
down each time you increase the size of the p-port.
You will also need six sacrificial rotor housings with different
p-port timings. Did Everett or Jim do that? I don't think so.
This sort of  trial and error applied research is economically
beyond the average cottage industry or shade tree rotary engine tuner.

Just copy the Leman engine for *&^%$#@ sakes!

Paul Lamar

Paul,

  I sure dont want to get into a debate with you trying to defend another
man's position. And I agree that Everett Hatch (like all folks, me and you
included) probably wasnt infallible.

  Yes, I've read all the stuff you've written the past couple of years on
the subject of peripheral ports because its a subject that interests me. It
amazes me that the example you continually cite as the benchmark reference
for an aircraft application of PP tech is the Le Mans 4 rotor engine. It is
a very impressive piece of work. But I dont know of anyone on here who is
building a 4 rotor with tunable runner lengths. 

Why does that amaze you?
What does four rotor have to do with it? It is the HP per rotor
that counts. Divide the HP numbers by two and you get 240 HP at
6000 RPM. If you run it at a steady 6000 RPM the runner length
remains fixed. The slides do not move in and out at a steady 
6000 RPM. What is the problem with understanding that?

So I dont consider it as
applicable to the discussion as Everett's work. It strikes me as quite
simplistic to assume that simply cutting the Le Mans HP number in half is
appropriate. And I question whether an eyeball engineered copy will produce
the often quoted 240HP @ 6000 RPM.

  You went to a lot of trouble to explain that the combination of runner
size and length both contribute to optimize power for a given RPM. I'd
certainly agree with that. Unless I'm mistaken (its possible; I am
fallible) I believe its only length that is tunable in the Le Mans engine
isnt it? So presumably the fixed runner diameter was chosen to optimize
output at a given runner length and RPM (not likely 6000 RPM).

  It's not even remotely possible that Everett Hatch tested all possible
combinations of runner length and diameter. But in his presentation at
Copperstate 95 he stated that he did experiment with a number of
combinations of runner length, diameter, and port timing. And while he
didnt have the resources of Mazda his focus was on an aircraft application
tuned for operation at our desired RPM range. As such I will give more
weight to his data than you seem to be willing to.

  I hope someone else actually builds and tests a 2 rotor engine operating
at 6000 RPM using your theories that proves Everett wrong. Maybe Jerry is
the guy that will do that. Nothing would please me more than being able to
assemble a cheap PP engine that is proven to produce 240HP.

Mike Wills

IT IS NOT MY THEORIES! @#$%^%$#@! MAZDA HAS DONE IT!

Everett did a very good job. He got 210 HP. Ray Richardson and folks at 
the current Power Sport got another 5% by merely adding bell mouth intakes 
to what Everett did for a grand total of 215 to 220 HP. I say if you copy 
Mazda exactly with larger runners and ports you can get up to 240 HP
at 6000 and much much more with a 2.85:1 gear box and 7500 RPM.

Yes, I agree the optimum diameter, for 6000 might be different and even more
than 240 HP might be possible. So far nobody, nada, no one else, except Mazda, 
has come even close to 240 HP at 6000 RPM.
 
Paul Lamar
 
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