Pobjoy R

R
	Preserved Pobjoy R at the Shuttleworth Collection
Type	Piston radial aero-engine
Manufacturer	Pobjoy Airmotors
First run	1926
Major applications	BA Swallow; Comper Swift

The Pobjoy R is a British seven-cylinder, radial, air-cooled, aircraft engine designed and built by Pobjoy Airmotors.^[1] Introduced in 1926 it was a popular engine for ultralight and small aircraft in the 1930s. A notable feature of the Pobjoy R was the propeller reduction gear which allowed the small engine to operate at more desirable higher speeds.

Applications[]

Engines on display[]

A preserved Pobjoy R engine is on display at the Shuttleworth Collection, Old Warden, Bedfordshire.^{[citation needed]}

Two Pobjoy R engines, one installed in the remains of Comper Swift (R222 / LV-FBA) will be soon on display at the in Buenos Aires Province, Argentina.^{[citation needed]}

Specifications (Pobjoy R)[]

Data from Lumsden.

General characteristics

Type: 7-cylinder air-cooled, radial, left-hand tractor
Bore: 3.03 in (77 mm)
Stroke: 3.43 in (87 mm)
Displacement: 173.05 cu in (2.84 L)
Diameter: 25.5 in (647.7 mm)
Dry weight: 135 lb

Components

Oil system: Dry sump
Cooling system: Air-cooled

Performance

Power output: 85 hp
Specific power: 0.5 hp/cu in
Fuel consumption: 4.9 imp. gallons per hour
Power-to-weight ratio: 0.63 hp/lb

References[]

Notes[]

^ Lumsden 2003, p.178.

Bibliography[]

Guttery, T.E. The Shuttleworth Collection. London: Wm. Carling & Co, 1969. SBN 901319-01-5
Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.

[1] Lumsden 2003, p.178.

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