may be the twin-turbo version of your 13B engine meant to electricity the 3rd-generation RX-7 launched in late 1991. Each and every rotor on 13B-REW has one combustion chamber volume of 654cc. With two rotors, the total displacement was 1308cc. Best fit to get a Mazda swap or replacement venture. If the engine fails in just this period, Orbi Mot