> >>> 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

 > Mike,    I am going to try.   As soon as the cooling package is
finalized, I will be working on the p ports. While someone (MAZDA
among others) has a great deal of specific information about p port
size, shape and location and runner length, they are not sharing the
information.  Propably the best we can do is to follow Paul's advice
to scale off the one drawing we do have.  However, even this is
problematical.   Photo Copy machines as far as I know can do blow
ups at certain set percentages such as  150% or 200 %.   That is
useless.  What I want to do is set known boundries  such as the top
and bottom edges of the rotor housing on the page and then expand
the drawing to line up with these.  Then we could transfer the
measurments.  Anybody know a way to do this, I am listening.   I
also would like to just follow Lynn's advice re. timing.  He has
experience and everything he has said on this list has been useful
good information.  Then Jim Mederer said flat out it would not work.
I know that I don't know enough to resolve their differences.  It
would be nice to have clarity BEFORE blasting  holes in my rotor
housings.       Jerry

Jerry not useless. If you can scale the rotor dwg to half scale
just double all your measurements. If it is 1/3 scale multiple all
your measurements by 3 and so on. Measure the height of the rotor
housing on the drawing and use that as your base number.
Lets say a real rotor housing is 12 inches high and the measurement
off your blow up dwg is 8 inches. Than multiply all measurements
on the drawing by 12/8 or 1.5. This will get you more than close enough.

Paul Lamar
 
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