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