Tornado HG641 with Centaurus radial engine at Langley
The rapid advancement in aviation technology during the 1930s placed increasing demands on aircraft engines. Although the Hercules engine had just completed its type test, development on a larger project, the Centaurus, was already underway. The Air Ministry awarded a development contract for the Centaurus in February 1938. This engine retained the same cylinder bore as the Pegasus, Mercury, and Hercules at 5.75 inches, but its stroke was extended to 7.0 inches, resulting in a displacement of 3270 cubic inches (53.6 liters) from its 18 air-cooled cylinders.
Despite its development throughout World War II, the Centaurus had a limited impact on the British war effort. This was due to a severe shortage of engineers and persistent technical issues that were not resolved until after the war. The Centaurus incorporated several design changes compared to the Hercules. Unlike the Hercules, which drove all its sleeves from the front with extension shafts running between the front cylinders to power the rear cylinder sleeves, the Centaurus drove the rear sleeves directly from the rear, eliminating the need for such complex drive arrangements.
The Centaurus development faced a major setback when Roy Fedden, who had been the driving force behind all Bristol engine projects, was dismissed by the Bristol board of directors in October 1942. This decision, particularly during the height of World War II, was unexpected given Fedden’s pivotal role in Bristol’s engine advancements. His dismissal was the culmination of long-standing tensions between him and the board. Before his departure, Fedden had introduced injection carburetion based on the successful Bendix injection system.
Despite its conceptual similarity to the Hercules, the Centaurus encountered numerous development issues, resulting in a relatively small production run of just 2800 units during the war.