Is definitely the twin-turbo Model on the 13B engine intended to electric power the third-technology RX-7 introduced in late 1991. Each individual rotor on 13B-REW has only one combustion chamber volume of 654cc. With two rotors, the full displacement was 1308cc. Best match for the Mazda swap or alternative project. https://mazda13bmotorforsale16936.bloggazza.com/29140141/13b-turbo-2-engine-for-sale-can-be-fun-for-anyone