The Pobjoy Niagara is a British seven-cylinder, air-cooled,

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance, a directional coordinate in a polar coordinate system * Radial set * A bearing f ...

, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a noticeable off-centre mounting for the propeller. The Niagara was a popular engine for light and experimental aircraft, well regarded due to its small diameter, smooth operation, low noise and innovative engineering.

Variants

;Niagara I :Bore/stroke 77 x 87 mm (3.03 x 3.43 in), swept volume 2,835 cc (173 cu in). Compression 6.25:1, gearing 0.47:1. Normal continuous power 84 hp (63 kW) at 3,200 rpm at sea level. ;Niagara II :Bore/stroke 77 x 87 mm (3.03x3.43 in), swept volume 2,835 cc (173 cu in). Compression 6.0:1, gearing 0.39:1. Normal continuous power 84 hp (63 kW) at 3,200 rpm at sea level. ;Niagara III :Bore/stroke 77 x 87 mm (3.03x3.43 in), swept volume 2,835 cc (173 cu in). Gearing 0.47:1. Normal continuous power 88 hp (66 kW) at 3,300 rpm at sea level. ;Niagara IV :Similar to Niagara III but with a higher operating rpm. Normal continuous power 98 hp (73 kW) at 3,500 rpm at sea level. ;Niagara V :Larger version of the basic Niagara. Bore/stroke 81 x 87 mm (3.19 x 3.43 in), swept volume 3,138 cc (191.5 cu in). Compression 8.0:1, gearing 0.47:1. Normal continuous power 125 hp (93 kW) at 4,000 rpm at sea level. ;Cataract I-III :De-rated, uncowled versions of Niagara I-III with simple inter-cylinder baffles for cooling and trickle-down lubrication for lower exhaust rockers. Compression 5.7:1, gearing 0.47:1.Jane's All the World's Aircraft p.26dOrd-Hume p.589 ;Cascade :Direct drive version of Cataract I. Normal continuous power 66 hp (49 kW) at 2,100 rpm.

Applications

Niagara

* Aeroput MMS-3 * Airspeed Fleet Shadower * CLW Curlew * Comper Kite *

Comper Swift The Comper C.L.A.7 Swift is a British 1930s single-seat sporting aircraft produced by Comper Aircraft Company Ltd of Hooton Park, Cheshire. Design and development In March 1929 Flight Lieutenant Nicholas Comper left the Royal Air Force and form ...

* General Aircraft Monospar ST-25 *

General Aircraft Fleet Shadower The General Aircraft G.A.L.38 Fleet Shadower was a British long-range patrol aircraft design of the immediate pre-Second World War period. The Fleet Shadower was a highly specialized aircraft intended to follow enemy naval task forces over long t ...

* Gribovsky G-25 * Lambach HL.I * Moss M.A.1 * Pobjoy Pirate *

Saro Shrimp The Saunders Roe A.37 Shrimp was a 1930s British two-seat four-engined experimental flying boat built by Saunders-Roe Limited ("Saro") at Cowes. Development The Shrimp was designed by H Knowler in 1939 as a half-size research aircraft as par ...

* Shapley Kittiwake * Short Scion Senior *

Short Scion The Short S.16 Scion and Scion II were 1930s British two-engine, cantilever monoplanes built by Short Brothers and (under licence) by Pobjoy Airmotors and Aircraft Ltd. in Rochester, Kent between 1933 and 1937. Altogether 22 Scion/Scion II a ...

* Short S.31 (half scale Stirling) *

Spartan Clipper The Spartan Clipper was a British light touring aeroplane of the 1930s. It was a single-engine, two-seat, low-wing monoplane with a fixed tailwheel undercarriage. Development H.E. Broadsmith designed the Clipper as a two-seater; he employed th ...

* Westland CL.20

Cataract

British Klemm Swallow The B.A Swallow was a British light aircraft of the 1930s. It was a license-built version by the British Klemm Aeroplane Company (which later became known as the British Aircraft Manufacturing Co.) of the German Klemm L.25. A total of 135 were ...

Hafner A.R.III Gyroplane The Hafner A.R.III Gyroplane was a British 1930s experimental autogyro designed by Austrian Raoul Hafner, and built by the A.R.III Construction Company at Denham, Buckinghamshire. Design and development The single-seat Gyroplane had a three-b ...

Hendy Hobo The Hendy 281 Hobo was a British single-seat light monoplane designed by Basil B. Henderson and built by the Hendy Aircraft Company at Shoreham Airport in 1929. Only one aircraft was built, registered ''G-AAIG'', and first flown in October 1929 ...

* Pitcairn PA-22

Cascade

* Autogiro AC-35

Survivors

A Pobjoy Niagara powered

G-ACTF that is owned and operated by

The Shuttleworth Collection The Shuttleworth Collection is a working aeronautical and automotive collection located at the Old Warden Aerodrome, Old Warden in Bedfordshire, England. It is the oldest in the world and one of the most prestigious, due to the variety of old ...

Old Warden Old Warden is a village and civil parish in the Central Bedfordshire district of the county of Bedfordshire, England, about south-east of the county town of Bedford. The 2011 census shows its population as 328. The Shuttleworth Collection of ...

remains airworthy in 2017 and displays to the public at home airshows during the flying season.www.shuttleworth.org
Retrieved: 28 February 2017.

Engines on display

A preserved Pobjoy Niagara engine is on public display at the

Science Museum (London) The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and is one of the city's major tourist attractions, attracting 3.3 million visitors annually in 2019. Like other publicly funded ...

Specifications (Pobjoy Niagara IV)

References

Notes

Bibliography

* * Gunston, Bill. ''World Encyclopedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. . *

External links

Pobjoy Niagara at oldengine.org"A New Pobjoy Engine"
- article in ''Flight'' {{Pobjoy aeroengines Niagara 1930s aircraft piston engines Aircraft air-cooled radial piston engines