Bristol Centaurus

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Preserved Bristol Centaurus engine
Type Piston aircraft engine
Manufacturer Bristol Aeroplane Company
First run July 1938
Major applications Hawker Tempest
Bristol Brabazon
Hawker Sea Fury
Number built c.2,500

The Centaurus was the final development of the Bristol Engine Company's series of sleeve valve radial aircraft engines, an 18-cylinder, two-row design that eventually delivered over 3,000 hp (2,200 kW).[1] It was introduced into service late in World War II, and was one of the most powerful aircraft piston engines to see service.

The Royal Navy Historic Flight currently operates a Hawker Sea Fury, powered by a Bristol Centaurus.

Design and development[edit]

Like most Bristol Engines designs, the Centaurus was based on the mechanicals of an earlier design, in this case the "classic" 5.75 in (146 mm) piston from their original 1918 Jupiter. The Jupiter piston was still in use in the contemporary 14-cylinder Hercules, which was being brought into production during the design of the Centaurus. The Centaurus had a cylinder swept volume of 3,272 in³ (53.6 l), close to that of the American Wright Duplex-Cyclone American large radial, making the Centaurus one of the largest aircraft piston engines to enter production, while that of the Hercules was 2,363 cubic inches (38.7 l). The nearly 40% higher capacity was achieved by increasing the stroke from 6.5 to 7 in (170 to 180 mm), and by changing to two rows of nine cylinders instead of two rows of seven, but the overall diameter of the Centaurus was only just over 6% greater.[2] The cylinder heads had an indentation very much like an inverted top hat, which of course was successfully finned but it was difficult to get air straight down into this hollow to adequately cool the head. During the development stage the engineers at Bristol Aeroplane contacted ICI (Metal Division), Birmingham to enquire whether a copper chromium alloy would have sufficient high temperature strength and higher thermal conductivity to be used for this purpose. Tests successfully concluded that with the same volume of cylinder the use of these modified heads enabled the horsepower per cylinder to be raised from 110hp to 220hp and became the main development for the Centaurus engines. ( Metals in the Service of Man. W O Alexander & A C Street)

Sleeve valve closeup from a Bristol Centarus Mark 175.

Bristol maintained the Centaurus from type-testing in 1938[2] but production could not start until 1942 owing to the need to get the Hercules into production and improve the reliability of the entire engine line. Nor was there any real need for the larger engine at this early point in the war, when most military aircraft designs were intended to mount engines around 1,000 hp. The Hercules' approximately 1,500 hp was simply better suited to the existing airframes then in production.

Cross Section of a Bristol Centarus Mark 175

In fact, the Centaurus did not see any use until near the end of the war, first appearing on an upscaled version of the Vickers Wellington, the Warwick. Other wartime, or just-postwar, applications included the Bristol Brigand and Buckmaster, Hawker Tempest and Sea Fury, and the Blackburn Firebrand and Beverley. The engine also saw post-war use in civilian airliners, including the ill-fated Bristol Brabazon.

By the end of the war in Europe, around 2,500 examples of the Centaurus had been produced by Bristol.[2]

The most powerful version of the Centaurus developed was intended for the Blackburn Beverley transport aircraft. Utilising direct injection, it achieved a remarkable 3,220 hp, but was never fitted.[3]

A projected enlarged capacity version of the Centaurus was designed by Sir Roy Fedden, cylinders were produced for this engine but it was never built. Known as the Bristol Orion (a name used previously for a variant of the Jupiter engine, and later re-used for a turboprop one) this development was also a two-row, 18 cylinder sleeve valve engine with the displacement increased to 4,142 cubic inches (67.9 l)[4] (6.25x7.5), nearly as large as the massive American Wasp Major four-row, 28-cylinder radial, the largest displacement aviation radial engine ever placed in quantity production.


The Centaurus was produced in 34 variants ranging from the 2,000 hp (1,490 kW) Centaurus I to the 2,405 hp (1,793 kW) Centaurus 663 for the Airspeed Ambassador airliner. The most powerful variants to enter service were the 2,625 hp (1,957 kW) Centaurus 170, 173, 660, 661 and 662.[5]


Bristol Centaurus powered Fairey Spearfish



The Royal Navy Historic Flight operates a Hawker Sea Fury powered by a Bristol Centaurus.[7]

Engines on display[edit]

Preserved Bristol Centaurus engines are on public display at the following museums:

Specifications (Centaurus VII)[edit]

A Centaurus with cylinders removed exposing the sleeve valves.

Data from Lumsden[8]

General characteristics

  • Type: 18-cylinder, air-cooled, two-row radial engine
  • Bore: 5.75 in (146 mm)
  • Stroke: 7 in (177 mm)
  • Displacement: 3,270 in³ (53.6 l)
  • Diameter: 55.3 in (1,405 mm)
  • Dry weight: 2,695 lb (1,223 kg)



See also[edit]

Related development
Comparable engines
Related lists



  1. ^ Gunston 1989, p.33.
  2. ^ a b c Bridgman (Jane's) 1998, p. 270.
  3. ^ Flight magazine, 11 May, 1956 Retrieved: 12 December 2014
  4. ^ Gunston 2006, p.152.
  5. ^ Lumsden 2003, pp.125-128.
  6. ^ List from Lumsden
  7. ^ Royal Navy Historic Flight - Aircraft Retrieved: 5 August 2009
  8. ^ Lumsden 2003, p.125.


  • Bridgman, L, (ed.) (1998) Jane's Fighting Aircraft of World War II. Crescent. ISBN 0-517-67964-7
  • Gunston, Bill. Development of Piston Aero Engines. Cambridge, England. Patrick Stephens Limited, 2006. ISBN 0-7509-4478-1
  • 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.

External links[edit]