Wankel rotors of 13B The 13B would be the most widely manufactured rotary engine. It was the basis for all long run Mazda Wankel engines, and was generated for over 30 decades. The 13B has no relation for the 13A. In its place, This is a lengthened Model from the 12A, acquiring 80 mm (three.So, the moment we’ve finished processing on a person eq