Will be the twin-turbo Edition on the 13B engine designed to electric power the 3rd-era RX-7 released in late 1991. Each rotor on 13B-REW has a single combustion chamber volume of 654cc. With two rotors, the entire displacement was 1308cc. Best healthy for just a Mazda swap or substitute job. https://angelocwnet.madmouseblog.com/19574684/about-13b-rotary-motor-for-sale