PZL Foka

P.Z.L. WS Foka
Type	family of air-cooled V-engines (8-cylinder/12-cylinder)
National origin	Poland
Manufacturer	Polskie Zakłady Škoda, State Aviation Works
Designed by	Stanisław Nowkuński, Jan Oderfeld
First run	1938
Number built	8
Program cost	over 5.5 million zł

P.Z.L. WS Foka (Polish: Seal) was a family of Polish air-cooled V-engines of the late 1930s. The Foka A was an 8-cylinder engine initially designed by Stanisław Nowkuński for the modern P.Z.L. P.38 Wilk fighter-bomber and P.Z.L. P.39 fighter, it was to start a family of high-performance engines for other types of Polish warplanes as well. The initial series was to achieve roughly 450 hp (340 kW) of power and eventually reach 600 horsepower (450 kW).

However, following the designer's death in 1936, the development met a number of serious setbacks. Taken over by a new team of designers, the basic problems with vibrations, overheating and high fuel consumption. By the time one of the early prototypes was installed in the second prototype of P.Z.L. P.38 Wilk, the engine provided only around 330 horsepower (250 kW). As P.Z.L. P.38 also had other serious issues, both projects were eventually cancelled after only 8 prototypes had been completed.

The successor to Foka A was Foka B, a V-12 engine intended as the powertrain of P.Z.L. P.48 Lampart, P.Z.L. P.45 Sokół, RWD 25, P.W.S.41 and L.W.S.3 Mewa. However, the outbreak of World War II prevented the first prototype from being completed.

In late 1934 the Aeronautics Department of the Polish Ministry of Military Affairs ordered the development of a high-power engine at the Polskie Zakłady Škoda company. The engine was to become the powerplant of P.Z.L. 38 and P.Z.L. 39 fighters, under development at the time, as well as other modern designs. The lead designer became Stanisław Nowkuński.

Earlier the same year Nowkuński created the GR-760 high-efficiency air-cooled radial engine. Used in a number of sports planes (notably the RWD 9), the engine won the Challenge International de Tourisme 1934 and a number of other tournaments. When tasked with designing a larger, more powerful engine for warplanes, Nowkuński decided to study the Farman 12bis and Ranger V-770 V engines. His new design, the Foka (Polish for seal) drew from both Nowkuński's earlier designs and the promising French and American constructions of the epoch. Similar to Ranger V-770, Foka had only 8 cylinders in an inverted-V configuration and also featured a reduction drive and mechanical supercharger allowing for up to 420 horsepower (310 kW) at 4000 revolutions.

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