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 (geometry), a directional coordinate in a polar coordinate system * Radial set * A ...

aero-engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbine ...

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 single-seat sporting aircraft designed and produced by the Comper Aircraft Company. It was the company’s first aircraft. The Swift was designed shortly after Nicholas Comper’s departure from the Royal A ...

* 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-World War II, Second World War period. The Fleet Shadower was a highly specialised aircraft intended to follow enemy naval forces o ...

* Gribovsky G-25 * Lambach HL.I * Moss M.A.1 * Pobjoy Pirate * Saro Shrimp * Shapley Kittiwake *

Short Scion Senior The Short S.22 Scion Senior was a 1930s United Kingdom, British four-engined nine-passenger floatplane built by Short Brothers. Design and development The Scion Senior was developed as an enlarged version of the Short Scion, Scion light transpo ...

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

* Short S.31 (half scale Stirling) * Spartan Clipper * Westland CL.20

Cataract

* British Klemm Swallow * Hafner A.R.III Gyroplane * Hendy Hobo * 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 aviation, automotive and agricultural collection located at Old Warden Aerodrome in Bedfordshire, England. History The collection was founded in 1928 by aviator Richard Ormonde Shuttleworth. While fl ...

Old Warden Old Warden is a village and civil parishes in England, 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 ...

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