Fellas,
It has been said that using RX-8 rotors in RX-7 rotor housings is a bad idea as the apex seals of an RX-8 are not designed to handle going over the peripheral exhaust port. Would it be possible to use RX-7 model apex seals in the RX-8 rotors as a way of overcoming this problem and gaining a slight increase in compression ratio?
Thanks,
Peacedog

 

Nope, the apex seal groves are not deep enough to fit RX-7 seals.

 

So if the new RX-8 style apex seals are effectively "shorter" than the older RX-7 style seals Why can't they handle the wear of going over a peripheral exhaust port? Are they softer, in terms of the material they are made out of, or somehow more brittle and therefore not able to handle the shock of the peripheral exhaust?
Thanks,
Peacedog

 

There just not designed for it, it works, but in my opinion is a bad idea. Especially since there is no HP gain at all from using Rx8 rotors in an earlier engine.

 

I imagine that the RX8 rotors could be machined to accept the 2 mm seal much like 2mm seal grooves are machined to accept 3mm seals. In fact I believe it has already been done and posted on this forum.

 

You can machine the RX-8 rotors deeper at the apex seal slot.

You could probably also just use the ceramic RX-8 apex seals as they will not "sag" over the P-port exhaust.

RX-8 rotor WILL make more power on a streetport IF you bother porting so the intake ports open earlier.

The sideseal location has been moved up toward the cornerseal tip so that earlier port opening can be achieved without dropping the leading edge of the sideseal into the port.

Search on "early opening streetport" to read up on this.

 

so they are better to use is that what you are saying blue tII

 

Only if you know how to port the sidehousings to take advantage of the new sideseal placement.