The Honda RA271 was Honda's second Formula One racing car, and its first to actually enter a race. The car was developed from the company's 1963 prototype, retrospectively designated RA270.
The RA271 made its race debut during the 1964 Formula One season, just one year after Honda started producing road cars, and was the first Japanese-built car ever to enter a round of the FIA Formula One World Championship. Although RA271s only contested three 1964 Grands Prix, driven on each occasion by American sports car racing-specialist Ronnie Bucknum, its innovative, transversely mounted, 1.5 L (92 cu in) V12 engine – sometimes cited as "the strongest engine of F1's 1.5-litre era" – formed the basis of Honda's race-winning RA272 of 1965 at the Mexican GP, driven by Richie Ginther (USA). The car's best result was at its debut, after withdrawing from the Belgian Grand Prix, at the 1964 German Grand Prix, where Bucknum was running 11th before spinning out and being classified 13th. He retired from both the Italian and United States Grands Prix, both times with mechanical failures.
He had run as high as 7th at Monza before a brake failure ended his race. Engine dimensions of the 1965 48-valve V12 were 58.1 x 47.0 mm 1,495.28 cc. 230 bhp (170 kW) at 13,000 rpm was quoted. This was the most powerful F1 engine of 1965. The engine was safe to 14,000 rpm. Since the 1967 4-cylinder 498.57 cc engine (57.5 x 48.0mm) eventually gave almost 90 bhp (67 kW) at 12,600 rpm, the V12 had the potential of 270 bhp (200 kW) with further development. It used 12 Keihin carburetors, one for each cylinder, later to be replaced by low pressure fuel injection before entry into the Italian GP.