Hello Mr. Lamar  and rotary people :)

I´m preparing my RX 7 for drift, and I think about engine.
I´m going to use RX 7 engine with RX 8 eccentric shaft and rotors, with
p-port and turbo. Cause I need about 500 HP.
Might it be working properly? What kind of turbo and waste gate should I
use?
Respectfully,
 Dibala, Slovakia

I am not sure an RX8 shaft will work with RX7 end housings. I would check with
Mazdatrix on that. Perhaps Cary knows. I think there is enough difference
in the shaft length. RX8 rotors will work. I think you are looking
for a p-port exhaust. It is possible to use a P-port exhaust rotor
housing in an RX8 and have three exhaust ports. That seems to work
very well. Way back in the early eighties Mazda made a 13B engine for
first gen RX7 that had the water O-rings in the rotor housing.
1984 and '85 GSL-SE: 13B engine. That P-port exhaust rotor housing
will work in the RX8 engine. That will give you 3 exhaust ports
per rotor.

It also solves a problem with highly boosted RX8 engines (over 350 HP)
that melt an iron bridge near the exhaust port. See the attached
picture. You might try modifying  the RX8 rotor housing with
an extra cooling water port and use an electric water pump to
feed cold water into this area.

It is also possible to put late 3rd gen RX7 rotor housings in an
NC mill and machine the O-rings groves for use in RX8 end housings.
That will also give you 3 exhaust ports per rotor. It also solves
the melting RX8 exhaust port problem.

Jeff Doddridge <4starr@cox.net> can do that for you if he has time.

"What kind of turbo and waste gate should I use?"

I don't know what works for high power engines. Generally the largest
one you can find :) Mazdatrix might help with that as they build drift
engines.


Paul Lamar