Yanmar of Japan produced some small, charge-cooled rotary engines for chainsaws and outboard engines. One of its products is the LDR (rotor recess in the leading edge of the combustion chamber) engine, which has better exhaust emissions profiles, and reed-valve controlled intake ports, which improve part-load and low rpm performance. In 1971 and 1972, Arctic Cat produced snowmobiles powered by Sachs KM 914 303-cc and KC-24 294-cc Wankel engines made in Germany. In the early 1970s, Outboard Marine Corporation sold snowmobiles under the Johnson and other brands, which were powered by OMC engines. Aixro of Germany produces and sells a go-kart engine, with a 294-cc-chamber charge-cooled rotor and liquid-cooled housings. Other makers include Wankel AG, Cubewano, Rotron, and Precision Technology. Non-internal combustion In addition to applications as an internal combustion engine, the basic Wankel design has also been used for gas compressors, and superchargers for internal combustion engines, but in these cases, although the design still offers advantages in reliability, the basic advantages of the Wankel in size and weight over the four-stroke internal combustion engine are irrelevant. In a design using a Wankel supercharger on a Wankel engine, the supercharger is twice the size of the engine. The Wankel design is used in the seat belt pre-tensioner system in some Mercedes-Benz and Volkswagen cars. When the deceleration sensors detect a potential crash, small explosive cartridges are triggered electrically, and the resulting pressurized gas feeds into tiny Wankel engines which rotate to take up the slack in the seat belt systems, anchoring the driver and passengers firmly in the seat before a collision. See also General Motors Rotary Combustion Engine Gunderson Do-All Machine Mazda RX-8 Hydrogen RE Mazda Wankel engine Mercedes-Benz M 950 Mercedes-Benz C111 O.S. Engines, the only licensed maker of Wankel model engines Pistonless rotary engine Quasiturbine RKM engine Liquidpiston Notes References F Feller and M I Mech: "The 2-Stage Rotary Engine—A New Concept in Diesel Power" by Rolls-Royce, The Institution of Mechanical Engineers, Proceedings 1970–71, Vol. 185, pp. 139–158, D55-D66. London P V Lamarque, "The Design of Cooling Fins for Motor-Cycle Engines", The Institution of Automobile Engineers Magazine, London, March 1943 issue, and also in "The Institution of Automobile Engineers Proceedings", XXXVII, Session 1942–1943, pp. 99–134 and 309–312. Walter G. Froede (1961): 'The NSU-Wankel Rotating Combustion Engine', SAE Technical paper 610017 M. R. Hayes & D. P. Bottrill: 'N.S.U. Spider -Vehicle Analysis', Mira (Motor Industry Research Association,