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