Piaggio P.XII
{{Short description|1930s Italian aircraft piston engine}}
| {{Infobox aircraft begin
|name= P.XII |image = File:Piaggio P.XII, Museo dell'aria e dello spazio (San Pelagio, Due Carrare).JPG |caption = The Piaggio P.XII displayed at Museo dell'Aria e dello Spazio in San Pelagio, Due Carrare, Province of Padua }} {{Infobox aircraft engine |type= Radial engine |national origin = Italy |manufacturer = Piaggio |first run = |major applications = Piaggio P.108 |number built = |program cost = |unit cost = |developed from = |developed into = |variants with their own articles = }} |
The Piaggio P.XII is an Italian 18-cylinder radial aircraft engine developed in the 1930s by Rinaldo Piaggio S.p.A. The P.XII was two Piaggio P.X engines in tandem, which were versions of the French Gnome-Rhône 9K Mistral made under license, themselves being much modified Gnome-Rhône 9A - a license-built Bristol Jupiter.
The engine was used in some Italian aircraft from 1940 until the end of World War II, especially the Piaggio P.108. An up-rated version was tested as the Piaggio P.XXII.
Variants
Variants of the Piaggio P.XII include:
(R - Riduttore - reduction gearing and C - Compressore - supercharged)
;P.XII R.C.35: (geared, rated altitude {{convert|3500|m|ft|abbr=on}})
;P.XII R.C.40: (geared, rated altitude {{convert|4000|m|ft|abbr=on}})
;P.XII R.C.100/2v: (geared, rated altitude {{convert|10000|m|ft|abbr=on}})
;P.XV R.C.60/2v: (geared, rated altitude {{convert|6000|m|ft|abbr=on}})
;P.XXII R.C.35D:Higher rating with slightly higher displacement than the P.XII series engines. (geared, rated altitude {{convert|3500|m|ft|abbr=on}})
;P.XXII R.C.35R:Same as P.XXII R.C.35D, but propeller rotates in opposite direction
;P.XXII R.C.60: (geared, rated altitude {{convert|6000|m|ft|abbr=on}})
Applications
Specifications (P.XII R.C.35)
{{pistonspecs|
|ref =Aircraft Engines of the World 1945.{{cite book |last=Wilkinson |first=Paul H. |title=Aircraft engines of the World 1945 |year=1945 |publisher=Paul H. Wilkinson |location=London |pages=306–307 |edition=2nd}}
|type = 18-cylinder air-cooled radial engine
|bore ={{convert|146|mm|in|abbr=on|2}}
|stroke ={{convert|176|mm|in|abbr=on|2}}
|displacement ={{convert|53|L|cuin|abbr=on}}
|length={{convert|1700|mm|in|abbr=on|2}}
|diameter={{convert|1410|mm|in|abbr=on|2}}
|width=
|height=
|weight={{convert|850|kg|lb|abbr=on|0}}
|valvetrain= 2 x overhead valves per cylinder operated by rockers and pushrods
|supercharger= Centrifugal compressor, geared to 7.81:1
|turbocharger=
|fuelsystem=Single Piaggio downdraught carburettor with automatic boost and mixture control
|fueltype=87 octane
|oilsystem=Pressure fed at {{convert|70|psi|kPa|abbr=on|1|disp=flip}}, dry sump
|coolingsystem=Air
|power=Take-off: {{convert|1500|hp|kW|abbr=on}} at 2,100rpm
- Military: {{convert|1350|hp|kW|abbr=on}} at 2,100rpm at {{convert|3500|m|ft|abbr=on}}
- Cruising: {{convert|1000|hp|kW|abbr=on}} at 1,700rpm at {{convert|3500|m|ft|abbr=on}}
|specpower= 22.29 kW/L (0.49 hp/cu in)
|compression=6.5:1
|fuelcon=
|specfuelcon=0.2795 kg/kW/hr (0.46 lb/hp/hr)
|oilcon=0.0134 kg/k/w/hr (0.022 lb/hp/hr)
|power/weight= 1.324 kW/kg (0.8 hp/lb)
|designer=
|reduction_gear=Epicyclic reduction gear, gear ratio: 0.62:1
|general_other=Frontal Area: {{convert|1.56|m²|sqft|abbr=on|1}}
|components_other=Starter: Garelli compressed air starter
- Ignition: 2x Marelli AQ18 magnetos, 2 x spark plugs per cylinder fed by a shielded ignition harness.
|performance_other=
}}
See also
{{aircontent
|see also=
|related=
|similar aircraft=
|lists=
|similar engines=
}}
References
{{Commons category}}
= Notes =
{{reflist}}
= Bibliography =
- Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. {{ISBN|1-85260-163-9}}
- Wilkinson, Paul H.. Aircraft Engines of the World. 1941
{{Piaggio aeroengines}}
Category:Aircraft air-cooled radial piston engines