May be the twin-turbo Edition of the 13B engine built to power the 3rd-technology RX-7 introduced in late 1991. Just about every rotor on 13B-REW has an individual combustion chamber quantity of 654cc. With two rotors, the entire displacement was 1308cc. Best match for a Mazda swap or substitute challenge. https://13brotarymotorforsale83604.bcbloggers.com/29299010/mazda-rx7-engine-for-sale-secrets