Piaggio P.X

Piaggio acquired a license from Gnome et Rhône in 1925 for their engines derived from the Bristol Jupiter.{{sfn|Gunston|1986|page=125}} The designs proved successful and, using this experience, the company designed a range of related radial engines named "Stella", meaning star.{{cite web|title=PXI RC40 engine|website=Museo Piaggio|url=https://www.museopiaggio.it/en/modelli/piaggio-en|archive-url=https://web.archive.org/web/20170826223515/http://www.museopiaggio.it/en/modelli/piaggio-en|archive-date=26 August 2017|access-date=27 March 2020|url-status=live}} The design was led by the engineer Renzo Spolti.{{sfn|Angle|1939|page=584}} 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 was 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.{{sfn|Wilkinson|1945|page=60}} It retained the same bore and stroke as the original Gnome-Rhône designs, {{convert|146|mm|in|abbr=on}} and {{convert|165|mm|in|abbr=on}} respectively, but was substantially more powerful than the comparable 9K.{{sfn|Angle|1939|page=584}} The engine had a two piece aluminium alloy crankcase, steel barrels for the cylinders and aluminium alloy heads. A Piaggio T2-80 updraught carburettor was fitted.{{sfn|Wilkinson|1945|page=302}} The basic version, the R., had reduction gear, while the R.C. was also equipped with a compressor.

The engine powered the Italian aircraft that served during World War II.{{sfn|Green|1967|page=111}} The IMAM Ro.43 was particularly noteworthy for its performance in the Battles of Cape Spartivento and Cape Matapan.{{sfn|Sadkovich|1994|page=98}}

;P.X R.: Normally aspirated and geared.

;P.X R.C.15: Supercharged and geared, rated at {{convert|1500|m|ft|abbr=on}}.

;P.X R.C.35: Supercharged and geared, rated at {{convert|3500|m|ft|abbr=on}}.

• IMAM Ro.37bis
• IMAM Ro.43
• IMAM Ro.44
• Savoia-Marchetti S.73
• Savoia-Marchetti S.74
• Savoia-Marchetti SM.81

{{pistonspecs|

|ref=Wilkinson, 1945 {{sfn|Wilkinson|1945|page=302}}

|type= 9-cylinder, single row, air cooled radial engine

|bore= {{convert|146|mm|in|abbr=on}}

|stroke= {{convert|165|mm|in|abbr=on}}

|displacement= {{convert|24.9|L|in3|0|abbr=on}}

|length= {{convert|1408|mm|in|abbr=on}}

|diameter= {{convert|1280|mm|in|abbr=on}}

|width=

|height=

|weight= {{convert|430|kg|lb|abbr=on}}

|valvetrain= 2 x overhead valves per cylinder operated by rockers and pushrods

|supercharger= Centrifugal compressor

|turbocharger=

|fuelsystem=

|fueltype= 87 Octane petrol

|oilsystem=

|coolingsystem= Air-cooled

|power=

• Take-off: {{convert|640|hp|kW|0|abbr=on}} at 2,250 rpm
• Cruise: {{convert|450|hp|kW|0|abbr=on}} at 1,800 rpm at {{convert|3500|m|ft|abbr=on}}

|specpower=

|compression= 6.0:1

|fuelcon=

|specfuelcon= 300 g/kWh (0.48 lb/(hp·h))

|oilcon= 8 g/kWh (0.018 lb/(hp·h))

|power/weight=

|designer=

|reduction_gear=

|general_other=

|components_other=

|performance_other=

}}

{{aircontent

|see also=

|related=

• Piaggio Stella P.IX

|similar aircraft=

|lists=

• List of aircraft engines

|similar engines=

• Gnome-Rhône 9K
• Nakajima Kotobuki
• Pratt & Whitney R-1340 Wasp

}}

{{reflist}}

• {{cite book |first= Glenn Dale |last=Angle |title=Aerosphere |year=1939 |place=New York }}
• {{cite book |last=Green |first=William |title=War Planes of the Second World War: Volume Six – Floatplanes |publisher=Macdonald |place=London |date=1967 |isbn=978-3-56014-509-1 }}
• {{cite book |last=Gunston |first=Bill |author-link=Bill Gunston |title=The Illustrated Encyclopedia of Combat Aircraft of World War II |place=London |publisher=Salamander Books |year=1978 |isbn=978-0-86101-017-2 }}
• {{cite book |first=Bill |last=Gunston|title=World Encyclopedia of Aero Engines |place=London |publisher=Guild Publishing |year=1986 |isbn=978-0-85059-717-2 }}
• {{cite book | last=Sadkovich |first=James |title=The Italian Navy in World War II |place=Westport |publisher=Greenwood Press |year=1994 |isbn=978-0-31328-797-8 }}
• {{cite book |last=Thompson |first=Jonathon W. |title=Italian Civil and Military Aircraft 1930–1945 |year=1963 |publisher=Aero Publishers Inc. |location=USA |isbn=978-0-81686-500-0 }}
• {{cite book |last=Wilkinson |first=Paul Howard |title=Aircraft Engines of the World |publisher=Paul H. Wilkinson |place=New York|year=1945 |url=https://archive.org/details/in.ernet.dli.2015.205335 |access-date=27 March 2020 }}

{{Piaggio aeroengines}}

P.X

Category:Aircraft air-cooled radial piston engines

Category:1930s aircraft piston engines