John B. Hege: Curtiss-Wright: All types of engines, both air- and water-cooled, , from 1958; license sold to Deere & Company in 1984 Fichtel & Sachs: Industrial and marine engines, , from 1960 Yanmar Diesel: Marine engines up to , and engines running on diesel fuel up to , from 1961 Toyo Kogyo (Mazda): Motor vehicle engines up to , from 1961 Perkins Engines: All types of engines, up to , from 1961 until <1972 Klöckner-Humboldt-Deutz: Engines running on diesel fuel; development abandoned by 1972 Daimler Benz: All types of engines from , from 1961 MAN: Engines running on diesel fuel; development abandoned by 1972 Krupp: Engines running on diesel fuel; development abandoned by 1972 Rheinstahl-Hanomag: Petrol engines, , from 1963; by 1972 taken over by Daimler-Benz Alfa Romeo: Motor vehicle engines, , from 1964 Rolls-Royce: Engines for diesel fuel or multifuel operation, , from 1965 VEB Automobilbau: Automotive engines from and , from 1965; license abandoned by 1972 Porsche: Sportscar engines from , from 1965 Outboard Marine: Marine engines from , from 1966 Comotor (NSU Motorenwerke and Citroën): Petrol engines from , from 1967 Graupner: Model engines from , from 1967 Savkel: Industrial petrol engines from , from 1969 Nissan: Car engines from , from 1970 General Motors: All types of engines, excluding aircraft engines, up to four-rotor engines, from 1970 Suzuki: Motorcycle engines from , from 1970 Toyota: Car engines from , from 1971 Ford Germany (including Ford Motor Company): Car engines from , from 1971 According to Don Sherman, American Motors also obtained a license. In 1961, the Soviet research organizations of NATI, NAMI, and VNIImotoprom commenced the development of a Wankel engine. Eventually, in 1974, development was transferred to a special design bureau at the AvtoVAZ plant. John B. Hege argues that no license was issued to any Soviet car manufacturer. Engineering Felix Wankel managed to overcome most of the problems that made previous attempts to perfect the rotary engines fail, by developing a configuration with vane seals having a tip radius equal to the amount of "oversize" of the rotor housing form, as compared to the theoretical epitrochoid, to minimize radial apex seal motion plus introducing a cylindrical gas-loaded apex pin which abutted all sealing elements to seal around the three planes at each rotor apex. In the early days, special, dedicated production machines had to be built for different housing dimensional arrangements. However, patented