I don't think we need to worry about apex seals in a non-turbo motor. Tracy's or Hurley's 2mm seals will never break in a NA motor since there is no problem with detonation. I just took some measurements of a '88 13b rotor: width measurements around the outside of the rotor showed 3.136 - 3.139 inches. Inside measurements from the gear face to the opposite side of the rotor (measured inside the bearing shell) was 3.144 to 3.145 inches. I do not have micrometers large enough to measure from an apex seal groove to the opposite curved face of the rotor. I don't have CAD capability so I can't send a drawing; can someone draw this up for us??? We need to compare these measurements to a RX8 rotor to see if the RX8 rotor will fit in the 'hole' of the earlier 13b's.
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Ken,
That's very true, and what I plan on doing for the single, do you think it's worth going to 3mm for a non - turbo single rotor?
The RX8 rotors are dirt cheap ( compared to new RX8 rotors) What dimensions do you want measured - I will do it for you!
George ( down under)
I don't see the need for a 'bridged' intake port on the RX8 engine. The RX8 also uses a 2mm apex seal; I think we can grind the RX8 rotor apex seal groove to the same depth as the older rotors then use Tracy's or Hurley's 2mm spex seals in a peripheral ported Renesis. You should be also be able to use the lighter 8.7 lb RX8 rotors in the older engines if you get the rotating assembly balanced. Wish I had a RX8 rotor so I could measure the critical dimensions (but not bad enough to buy one!(grin)).
Ken Powell
Bryant, Arkansas
501-847-4721