| 'P' | |
|---|---|
| Type | Piston radial aero-engine |
| National origin | United Kingdom |
| Manufacturer | Pobjoy Airmotors |
| Designer | Douglas Rudolf Pobjoy |
| First run | ca.1926 |
| Developed into | Pobjoy R |
The Pobjoy P was a British seven-cylinder, air-cooled, aircraft engine designed by Douglas Rudolf Pobjoy and built by Pobjoy Airmotors. It became the progenitor of the Pobjoy R/Niagara/Cataract family of small radial engines. A notable feature of the Pobjoy P was the propeller reduction gear which allowed the small engine to operate at more desirable higher speeds.
Applications
Specifications (Pobjoy P)
Data from Jane's all the World's Aircraft 1928
General characteristics
- Type: 7-cylinder air-cooled, radial, left-hand tractor
- Bore: 2.83 in (72 mm)
- Stroke: 3.43 in (87 mm)
- Displacement: 151.05 cu in (2.48 L)
- Diameter: 25 in (640 mm)
- Dry weight: 115 lb (52.16 kg)
- Designer: Douglas Rudolf Pobjoy
Components
- Valvetrain: overhead valves operated by rockers, push-rods and tappets driven by a cam-plate at the rear of the engine
- Fuel system: One Zenith carburetor
- Fuel type: 80% Petrol, 20% Benzol
- Oil system: Dry sump, pressure system at 45 psi (310 kPa)
- Cooling system: Air-cooled
- Reduction gear: Double-helical spur gear 0.524:1
Performance
- Power output: 60 hp (45 kW) at 3,000 rpm rated output; 67.5 hp (50.3 kW) at 3,300 rpm maximum
- Specific power: 0.397 hp/cu in (18.1 kW/L)
- Specific fuel consumption: 0.35 kg/kWh (0.57 lb/(hp⋅h))
- Oil consumption: 0.018 L/kWh (0.023 imp pt/(hp⋅h))
- Power-to-weight ratio: 0.858 kW/kg (0.522 hp/lb)
References
- ^ Lumsden, Alec S.C. (1994). British piston aero-engines and their aircraft (1. publ. in the UK. ed.). Shrewsbury: Airlife Publ. pp. 178–179. ISBN 1-85310-294-6.
- Grey, C.G., ed. (1928). Jane's all the World's Aircraft 1928. London: Sampson Low, Marston & company, ltd. pp. 18d–19d.
| Pobjoy aero engines | |
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