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 was a British seven-cylinder, 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

• British Aircraft Swallow
• Comper Swift
• Cosmopolitan Light Plane
• Couzinet 101
• General Aircraft Monospar
• Hendy Hobo
• Kay Gyroplane
• Lippisch Delta IV
• Mauboussin M.121P Corsaire Major
• Miles Satyr
• Pander Multipro
• Pobjoy Special
• Short Scion
• Short Scion Senior
• Spartan Clipper

Engines on display

A preserved Pobjoy R engine is on display at the Shuttleworth Collection, Old Warden, Bedfordshire. Two Pobjoy R engines, one installed on the remains of R222 (LV-FBA) Comper swift will be soon on display at the National Aviation Museum (Argentina-Moron-Buenos Aires Province)

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

See also

Related development

• Pobjoy Niagara

Related lists

• List of aircraft engines

References

Wikimedia Commons has media related to Pobjoy aircraft engines.

Notes

Bibliography