WSK WN-3
The WN-3 was a Polish seven-cylinder air-cooled radial engine of the 1950s, produced by WSK-Kalisz, designed by Wiktor Narkiewicz. Design and development. In 1946, Wiktor Narkiewicz, who prior to the Second World War was technical director of the Czechoslovakian Avia aero-engine factory, was appointed chief designer of the Polish Central Engine Office, and later the Aero-engine department of the Polish Aviation Institute ("Instytut Lotnictwa", IL). He led the design of the WN-1, a air-cooled flat-four piston engine which was the first post-war Polish aero-engine, followed by the WN-2 in  1947, but both of these engines failed to enter production. In 1952 Narkiewicz set up a small design team to design a new seven-cylinder radial engine, the WN-3. The first prototype, rated at was completed in 1954, and by the time testing was completed in 1955, the engine's power rose to . The WN-3 entered production in 1956, powering the PZL TS-8 Bies training aircraft. The engine was produced in 1957-1960 by WSK-Kalisz in Kalisz, it might be known also as PZL WN-3, or (in Western sources) as Narkiewicz WN-3.