Could be the twin-turbo Edition from the 13B engine built to power the third-era RX-7 released in late 1991. Every rotor on 13B-REW has a single combustion chamber quantity of 654cc. With two rotors, the entire displacement was 1308cc. Great fit for your Mazda swap or substitution venture. About VehicleHistory.com https://13brewforsale36781.blogdal.com/30177805/detailed-notes-on-rx7-13b-motor-for-sale