May be the twin-turbo Edition from the 13B engine designed to electric power the third-technology RX-7 released in late 1991. Each rotor on 13B-REW has only one combustion chamber volume of 654cc. With two rotors, the full displacement was 1308cc. Best match for just a Mazda swap or substitute project. https://mazda-rx7-engine-for-sale04691.bloggactivo.com/37980798/13b-turbo-engine-for-sale-an-overview