Will be the twin-turbo Model with the 13B engine meant to electrical power the third-technology RX-7 released in late 1991. Every single rotor on 13B-REW has a single combustion chamber volume of 654cc. With two rotors, the overall displacement was 1308cc. Great fit for your Mazda swap or substitution challenge. https://mazda-rx-7-engine07340.total-blog.com/an-unbiased-view-of-13b-turbo-2-engine-for-sale-55036077