I am building a steerport 12A and was going to use RX7 S2 rotors, but found the apex grooves worn. I have a set of Series 3 RX2/ Capella rotors that i want to use but would like to know are there any diffs between these in regards to weight, horsepower, SG strength, copression ratio etc.
The only difference i can find are the obvious combustion chamber shape.

 

Hope this helps http://www.mazdatrix.com/faq/rotorwgt.htm