The Piaggio P.X, or Piaggio Stella P.X, was an Italian nine-cylinder

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance, a directional coordinate in a polar coordinate system * Radial set * A bearing from ...

aircraft engine produced by Rinaldo Piaggio S.p.A. Based on experience license-producing

Gnome et Rhône Gnome et Rhône was a major French aircraft engine manufacturer. Between 1914 and 1918 they produced 25,000 of their 9-cylinder Delta and Le Rhône 110 hp (81 kW) rotary designs, while another 75,000 were produced by various licens ...

designs, the engine was used to power a number of aircraft during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, including the IMAM Ro.37bis and IMAM Ro.43, used extensively by the

Regia Aeronautica The Italian Royal Air Force (''Regia Aeronautica Italiana'') was the name of the air force of the Kingdom of Italy. It was established as a service independent of the Regio Esercito, Royal Italian Army from 1923 until 1946. In 1946, the mon ...

and

Regia Marina The ''Regia Marina'' (; ) was the navy of the Kingdom of Italy (''Regno d'Italia'') from 1861 to 1946. In 1946, with the birth of the Italian Republic (''Repubblica Italiana''), the ''Regia Marina'' changed its name to ''Marina Militare'' (" ...

respectively.

Design and development

Piaggio acquired a license from

in 1925 for their engines derived from the

Bristol Jupiter The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments tur ...

. The designs proved successful and, using this experience, the company designed a range of related radial engines named "Stella", meaning star. Design was led by the engineer Renzo Spolti. The engines were initially known by their number of cylinders, so the first nine-cylinder model in the range was the P.IX of 1933. However, a progressive number in Roman numerals were used as the design progressed, so the P.IX was followed by the P.X. The Stella P.X was a nine cylinder version of the P.VII. It retained the same bore and stroke as the original Gnome-Rhône designs, and respectively, but was substantially more powerful than the comparable 9K. The engine had a two piece aluminium alloy crankcase and steel barrels for the cylinders and aluminium alloy heads. A Piaggio T2-80 updraught

carburettor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

was fitted. The basic version, the R., had reduction gear, while the R.C. was also equipped with a

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can trans ...

. The engine powered Italian aircraft that served during

. The IMAM Ro.43 was particularly noteworthy for its performance in the Battles of

Cape Spartivento Domus de Maria is a ''comune'' (municipality) in the Province of South Sardinia in the Italian region Sardinia, located about southwest of Cagliari. Domus de Maria borders the following municipalities: Pula, Santadi, and Teulada. See also ...

and

Cape Matapan Cape Matapan ( el, Κάβο Ματαπάς, Maniot dialect: Ματαπά), also named as Cape Tainaron or Taenarum ( el, Ακρωτήριον Ταίναρον), or Cape Tenaro, is situated at the end of the Mani Peninsula, Greece. Cape Matap ...

Variants

;P.X R.: Normally aspirated and geared. ;P.X R.C.15: Supercharged and geared, rated at . ;P.X R.C.35: Supercharged and geared, rated at .

Applications

IMAM Ro.37bis The Meridionali Ro.37 ''Lince'' ( Italian: "Lynx") was a two-seater Italian reconnaissance biplane, a product of the ''Industrie Meccaniche Aeronautiche Meridionali'' (IMAM) company. It appeared in 1934 and had a composite structure of wood a ...

* IMAM Ro.43 * IMAM Ro.44 * Savoia-Marchetti S.73 * Savoia-Marchetti S.74 * Savoia-Marchetti SM.81

Specifications (R.C.35)

References

Citations

Bibliography

* * * * * * * {{Piaggio aeroengines Aircraft air-cooled radial piston engines 1930s aircraft piston engines P.X