Paul


This is the one of the earlier posts Oct.12th 2004 I received from you.  It
appears you have been talking about the Lemans P-port for years ad nauseam.
I can see the side profile of the Lemans drawing that you scaled from the
side view drawing but I hate to point out the obvious and that is how to
determine inner port shape from a side view drawing.

 Paul said....." There is nothing trick about the Lemans engine housing
shape. It is a more or less a large mostly round hole. You can scale the
 port diameter and timing from this drawing. I never understood why people
could not understand that while for the last five years we have been talking
about the Lemans geometry and port timing. I think I mentioned it many times
until I got tired of mentioning it over and over again. You can also scale
the fixed length of the runners and add the lengths from this chart for any
RPM between 6000 and 9000.


Well a mostly round hole doesn't tell me much.  A picture of the port from
the inside would be of immense help and end this issue once and for all.

The  Lemans engine housings were sitting with the innards removed  at the
your local Mazda festival last year so perhaps someone got a camera shot of
the inside.

Sorry to be so anal about this but 220 or 240hp is not good enough for me.

I am shooting for at least 300HP  at 8200 rpm NA.

Waiting to bore ... not you, the housing:)

DougFir

I don't have any pictures of the inside of the Lemans
rotor housings. Sorry. Note the height of the port
at the wear surface is the same as the round part outside
the rotor housing. That means it was probably not a
D shape. Now it could have been a slight rectangle
but I doubt it. There is nothing to be gained by
slowing the air just before it enters the rotor
housing. True the port open  area might increase
slightly faster and close slightly faster.
Making it rectangular is not going to help the apex seal.

You are picking nits Doug. The last little bit of die grinding
in this area will do very little. Study these VE charts again.

You will get 300 HP at 8200 RPM with almost any 1.875 inch
p-port shape. The Lemans engine got 320 HP at only 8000 RPM.
What you need to pay more attention to is the exact length
of the runners.

Paul Lamar ...No rotor no motor.

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