Designed by Louis Coatalen, the Sunbeam 350HP was an aero-engined car built by the Sunbeam Car Company in 1922, the first of several land speed record-breaking cars with aircraft engines.The car was fitted with an 18.3 liter V-12 Sunbeam Manitou aero engine. In aircraft trim this produced 300 hp, but was raised to 350 hp after a major re-design. A 4-speed transmission drove the differential-less rear axle, with a shaft drive rather than the hazardous chains of other cars. Brakes were crude, as was usual in the period, with a foot brake acting on the transmission and a hand brake on rear drums. Suspension was also typical, with half-elliptic springs all round.In May 1922, Kenelm Lee Guinness set the land speed record over a mile at 129.17 mph at the Brooklands racetrack.Malcolm Campbell drove the borrowed car at the Saltburn Speed Trials on June 17th 1922 and broke his first speed record at 138.08 mph.Campbell persuaded Coatalen to sell the Sunbeam to him, painted it blue and renamed it 'Blue Bird’.Over the winter of 1923-1924 the car was sent to the aircraft maker Boulton Paul in Norwich, for wind tunnel tests. They streamlined the car with a narrow radiator cowl at the nose and a long tapered tail. The rear wheels were also fitted with disk covers. Engine compression was raised by new pistons.The car was taken to Pendine Sands in South Wales and achieved the first of Campbell's official nine records: 146.16 mph on September 25th 1924. Blue Bird returned to Pendine in 1925, and on July 21st raised this record to 150.76 mph, the first time a car had exceeded 150 mph.