Australia, despite a population which is approximately seven-percent the size of that in the United States, is rabid for automotive performance—and not always the traditional kind. We’ve seen all sorts of off-the-beaten-path engines and cars come out of the Southern Hemisphere over the years, and that trend continues with this wicked 3-rotor Wankel rotary peripheral-port engine.
The video opens with the sound of the engine tearing your face off at high RPM, and then Chris Muscat of Centreline Suspension gives us a full rundown on the engine’s capabilities and engineering processes. The engine, which powers Centreline’s MX-7 Sports Sedan, is built to run in the Australian Sport Sedan Championship among other racing venues.
The engine is run on premium pump fuel—which in Australia is 98 octane (RON)—and is topped out at about 500 horsepower currently. This is achieved at 9,400 rpm, through the use of an innovative variable-runner intake manifold from Gunn Induction, which gets shorter as the revs climb. It uses an electric motor to control the length of the slides, which help the engine to think it’s larger than it really is. This helps to improve the torque, which gets the car out of corners more effectively on the road course.
One thing to note in particular regarding this engine: porting performed on a rotary engine is far different than that performed to a traditional overhead-valve or overhead-cam engine, as the engine operates in a completely different manner than these traditional types of engines.
In the most extreme examples of the 13B family, where peripheral porting is used, the traditional intake and exhaust ports (located on the side housings, or “irons”) are filled in, and new circular ports are machined into the rotor housings. This means that the port timing isn’t determined by the leading and trailing edges of the rotor, instead, port timing is controlled by the apex seals passing over the larger peripheral port openings. Although this will basically wreck the low-end performance, the high-RPM performance gains at 9,000 rpm and above are massive, which is why this style of porting is used in all-out rotary racing engines.
MoTeC engine management is used to control the engine, and the team uses constant development and research to continue to refine the platform. Follow along with the video to learn more about the program, and take an opportunity to hear this rotary engine scream!