May be the twin-turbo version on the 13B engine designed to electricity the third-era RX-7 introduced in late 1991. Each rotor on 13B-REW has an individual combustion chamber quantity of 654cc. With two rotors, the entire displacement was 1308cc. Great in shape to get a Mazda swap or substitution project. https://13b-turbo-2-engine-for-sa26036.blogolize.com/built-13b-motor-for-sale-an-overview-77935170