Producing over 90 bhp and capable of top speeds over 140 mph, the F1 drew considerable praise from the motorcycle press of the time. (Photo: Nolan Woodbury) » More Photos

Think of the rotary layout as a sort of alloy and steel sandwich; first, a bottom plate seals the first rotor housing; add a middle wall, the second chamber/rotor assembly, and finally, the top housing plate to seal that chamber. Running horizontally through the assembly is an output shaft that functions much like a normal crankshaft would, supported by bearings to travel through the center of each rotor with a timed/offset, with each lobe being geared to the inside diameter of the two rotors with a matching tooth pattern. The combustion process is simple; as the rotor turns it draws atmosphere and fuel from an intake port, turns again to compress and ignite it in another section of the housing (using conventional spark and ignition), and then rotates again to push waste gasses through the exhaust ports. This process powers the output shaft, which spins in a threeto- one ratio with the rotors. Displacement and compression figures are determined by grooves cut into the rotor’s faces to “tune” the engine for specific characteristics. In Norton’s case, both air- and liquid-cooling was used, the latter featuring passageways to flow coolant through the housing.

Those earliest air-cooled versions, conceived in the early ‘70s wore BSA, Triumph and finally Norton flavored underpinnings, which were all eventually deemed insufficient. But before selling NVT to investor Philippe LeRoux, Norton developed its first “Mark I” production prototype rotary in 1979 under the newly formed Norton Motors Ltd heading, the motorcycle division of LeRoux’s Norton Group PLC banner. That machine spawned the Mark II prototype, which eventually begat the production Interpol II. One hundred thirty of those were tagged for English police use in 1983, and more were supplied to the British armed forces. Using a twin rotor design that multiplied to a total of 588cc, in 1988 Norton Motors released a civilian version called the Classic. This was the first order of business for LeRoux, who hoped to draw investment opportunities by dangling the influentional Norton name before the noses of wealthy English businessmen. “But remember,” says Negus, “the Wankel was seen by many around the world as THE engine of the future. Bert Hopwood discussed putting a Wankel engine in a motorcycle chassis years before, and some prototypes using BSA cycle parts with Fichtel & Sachs engines appeared later. I actually saw one of these during my time at the BSA/Triumph R&D Umberslade.”