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
Lynn,
That Factory P-port, is it a 12A, and if so are there factory 13B
P-ports?
George (down under)
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