The Rolls-Royce Buzzard is a British piston aero engine of 36.7 litres capacity that produced about 800 horsepower (600 kW). Designed and built by Rolls-Royce Limited it is a V12 engine of 6 in (150 mm) bore and 6.6 in (170 mm) stroke. Only 100 were made. A further development was the Rolls-Royce R engine. The Buzzard was developed by scaling-up the Rolls-Royce Kestrel Engine.