Rolls-Royce Merlin exhaust flow and waste-gates, meant that this option was rejected in favour of the two-stage supercharger. Fitted with the two-stage two-speed supercharger, the Merlin 60 series gained 300 horsepower (224 kW) at over the Merlin 45 series, at which altitude a Spitfire IX was nearly faster than a Spitfire V. The two-stage Merlin family was extended in 1943 with the Merlin 66 which had its supercharger geared for increased power ratings at low altitudes, and the Merlin 70 series that were designed to deliver increased power at high altitudes. While the design of the two-stage supercharger forged ahead, Rolls-Royce also
Rolls-Royce Limited Rolls-Royce Limited Rolls-Royce was a British luxury car and later an aero engine manufacturing business established in 1904 by the partnership of Charles Rolls and Henry Royce. Building on Royce's reputation established with his cranes they quickly developed a reputation for superior engineering by manufacturing the "best car in the world". The First World War brought them into manufacturing aero engines. Joint development of jet engines began in 1940 and they entered production. Rolls-Royce has built an enduring reputation for development and manufacture of engines for defence and civil aircraft. In the late 1960s Rolls-Royce became hopelessly crippled by its