Pobjoy Niagara
The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, 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,[1] well regarded due to its small diameter, smooth operation, low noise and innovative engineering.
| Niagara | |
|---|---|
 | |
| Pobjoy Niagara on display at the Science Museum, London | |
| Type | Piston radial aero engine |
| Manufacturer | Pobjoy Airmotors |
| First run | 1934 |
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.[2]
- 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.[2]
- 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.[2]
- 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.[2]
- 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.[2][3]
- 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.[2][3][4]
- Cascade
- Direct drive version of Cataract I. Normal continuous power 66 hp (49 kW) at 2,100 rpm.[4]
Applications
Niagara
- Aeroput MMS-3
- Airspeed Fleet Shadower
- CLW Curlew
- Comper Kite
- Comper Swift
- General Aircraft Monospar ST-25
- General Aircraft Fleet Shadower
- Gribovsky G-25
- Lambach HL.I
- Moss M.A.1
- Pobjoy Pirate
- Saro Shrimp
- Shapley Kittiwake
- Short Scion Senior
- Short Scion
- Short S.31 (half scale Stirling)
- Spartan Clipper
- Westland CL.20
Cascade
Survivors
A Pobjoy Niagara powered Comper Swift G-ACTF that is owned and operated by The Shuttleworth Collection, Old Warden remains airworthy in 2017 and displays to the public at home airshows during the flying season.[5]
Engines on display
A preserved Pobjoy Niagara engine is on public display at the Science Museum (London).
Specifications (Pobjoy Niagara IV)
Data from Lumsden.[2]
General characteristics
- Type: 7-cylinder, air-cooled, radial engine
- Bore: 3.03 in (77 mm)
- Stroke: 3.43 in (87 mm)
- Displacement: 173 cu in (2.8 L)
- Diameter: 26.5 in (673 mm)
- Dry weight: 130 lb (59 kg)
Components
- Valvetrain: 1 inlet and 1 exhaust valve per cylinder
- Fuel system: 1 Claudel-Hobson carburettor
- Fuel type: 70 octane
- Cooling system: Air-cooled
Performance
- Power output: 98 hp at 3,625 rpm max at sea level
- Compression ratio: 6:1
- Power-to-weight ratio: 0.75 hp/lb
See also
Related development
Comparable engines
Related lists
References
Notes
- Gunston 1989, p.111.
- Lumsden 2003, p.179.
- Jane's All the World's Aircraft p.26d
- Ord-Hume p.589
- www.shuttleworth.org Retrieved: 28 February 2017.
Bibliography
- Grey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. ISBN 0-7153-5734-4.
- Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
- Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.
- Ord-Hume, Arthur W.J.G. (2000). British Light Aeroplanes. Peterborough: GMS Enterprises. ISBN 978-1-870384-76-6.
External links
- Pobjoy Niagara at oldengine.org
- "A New Pobjoy Engine" - article in Flight