Bristol Centaurus

The Centaurus was the final development of Bristol Engine Company's series of sleeve valve radial aircraft engines, an 18-cylinder two-row design that eventually delivered over 3,000 hp (2.2 MW).

Development

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 capacity of the Centaurus was increased by a longer stroke and changing to two rows of nine cylinders instead of two rows of seven. The resulting engine raised the displacement from the Hercules's 2,364 cubic inches (38.7 L) to a massive 3,270 cubic inches (53.6 L), making the Centaurus one of the largest piston aircraft engines to enter production.

While Bristol maintained the Centaurus dated from 1938, 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 of 1,000 hp or a little more. The Hercules' approximately 1,500 hp was simply better suited to the existing airframes then in production.

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 Blackburn Firebrand. The engine also saw post-war use in civilian airliners, including the ill-fated Bristol Brabazon.

Other piston engines of similar or greater displacement were developed around the same time in the United States, such as the Pratt & Whitney R4360 (Wasp Major) and the Wright R-3350 (Duplex Cyclone), but neither could be considered as successful during the war. The Duplex Cyclone was infamous for bursting into flames on takeoff, and both designs required considerable development periods before becoming reliable enough for civilian use. The Centaurus, on the other hand, was considered to be very reliable right from 1942, once the initial bugs had been worked out. The American engines saw greater numerical use, however, a side effect of the sizes of the two aircraft industries in the post-war era.

Specifications (Centaurus VII, 1942)