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–Bentley L-series V8 engine Crewe plant, and takes nearly 30 hours to build. The twin-turbo V8 engine was reported to be phased out, although it continues to be cast by Grainger and Worrall in Bridgnorth, Shropshire, England and fully machined and partially assembled at the company's machining facility in Telford, Shropshire, England. BMW began supplying Rolls-Royce and Bentley with engines in 1998, specifically a V12 engine for the Rolls-Royce Silver Seraph and a twin-turbo 4.4-litre V8 engine to replace the 6.75-litre for the Bentley Arnage. BMW V8 engines were used exclusively in the Arnage from 1998 to 2000. Vickers plc placed the Rolls-Royce and