Does anyone know the IO/IC and size and HP of the factory P-port.

 

Lynn, does the timing given, calculated by the rotor uncovering and covering the port, or the side seal uncovering/covering the port opening?

I was thinking the RX8 rotor will be slightly different (bigger) with the harased edges.

George ( down under)

I only have 12A stuff, but here you are:

 

Intake port at the manifold.    1.695" Round

 

Exhaust port at the manifold  1.645" Round

 

IO  86 Degrees BTDC

IC  75 Degrees ABDC

EO 73 Degrees BBDC

EC 65 Degrees ATDC

 

A Racing Beat Street Port:

 

IO  25 Degrees ATDC

IC  60 Degrees ABDC

EO 84 Degrees BBDC

EC 48 Degrees ATDC

 

In side port engines, it is the rotor closing the port.

In the peripheral port engines it is the apex seal closing the port. Actually the port is timed by the apex seal.

The port never closes in the way the side port engine has the rotor blank off the port in operation.

So, the Pport can flow way more than the side port, even with smaller runners and ports.

 

Lynn E. Hanover