This  subject keeps coming up from time to time.
  I thought we had it put to bed  years ago :)

  The  p-port valve overlap is of no consequence in a  high RPM, high power
  aircraft
  engine just like it was not a problem on the  1991 LeMans winning
  engine and
  the p-port 3 rotor engines now running and  winning in the Rolex GT
  races.
  These Le Mans engines had the lowest BSFC  every achieved in a rotary.

  The stock side port RX8 engine has no  overlap for Hc emissions
  reasons at
  idle and low rpm low power typical in  automotive use.

  Those engines in the Rolex GT RX8 are old 3 rotor  engines with p-ports.

  P-port engines have won many 24 hour races back  in the 1980's.

  There are no apex seal wear issues as the p-port area is  a very
  benign part
  of the rotary. There is no pressure difference across  the apex seals as
  they
  pass over the p-port. The 13B p-port hot exhaust is  far far harder on
  the
  apex seals than a much  cooler p-port  intake.


  The RX8 side exhaust/P-port intake is particularly good  combination
  as it idles as well as any 13B with side intake and p-port  exhaust.

  Read:
  http://www.rotaryeng.net/fund-of-intake.html
  http://www.rotaryeng.net/Welded-steel-p-port.html

  BTW  what is the valve overlap in a turbine engine?
  The rotary comes far closer  to a turbine engine in this regard
  than any piston  engine.

  Paul

  We drove the Pport 75 tube frame to the false grid. The Bridge ported 95
  tube frame had to be towed with a tractor. The Pport was quite docile
  even
  with  a 1:96 -1 first gear.

  Lynn E. Hanover



 Paul

 Is there any specific distance from the exhaust port to the intake
 P-port that has been identified other than just popping a hole in the
 center of the round boss in the casting??

 Is there a better optimum shape other than the round hole with the
 identified size...with a position to match??

 Isn't the P-port and turbo combination a match made in haven because of
 the large overlap and relatively mild RPM(6000 to 7000) keeping exhaust
 gases from finding there way into the intake stroke???

 I know these are old questions that have been addressed probably long
 ago, but I had to ask......



 jeff

 The proper dimension is the same as the Lemans engine.

 8.64 up from the bottom.

 Paul Lamar

Paul,

Is "8.64" a typo?  The drawing shows 8.55".  Can you confirm which is the
correct dimension to use as the center for boring the p-ports?

Thanks,
Mark

8.64 Mark. Send me the dwg with the typo so I can find it.

BTW I skinnied up the nose.
This rad IS 18 inch high and 30 inches long overall.

Here is all I have on the firewall shape so far.

The contoured SS tubes should be in any day (Larry?).

Paul Lamar