Formula Three

Formula Three (F3) is a third-tier class of open-wheel formula racing. The various championships held in Europe, Australia, South America and Asia form an important step for many prospective Formula One drivers.

Formula Three (adopted by the FIA in 1950) evolved from postwar auto racing, with lightweight tube-frame chassis powered by 500 cc motorcycle engines (notably Nortons and JAP speedway). The 500 cc formula originally evolved in 1946 from low-cost "special" racing organised by enthusiasts in Bristol, England, just before the Second World War; British motorsport after the war picked up slowly, partly due to petrol rationing which continued for a number of years and home-built 500 cc cars engines were intended to be accessible to the "impecunious enthusiast". The second post-war motor race in Britain was organised by the VSCC in July 1947 at RAF Gransden Lodge, 500cc cars being the only post-war class to run that day. Three of the seven entrants were non-starters, and, of the four runners, all but one retired on the first lap, leaving Eric Brandon in his Cooper Prototype (T2) trailing round to a virtual walk-over at an average speed of 55.79 mph (89.79 km/h), though his best lap (which was the fastest recorded for any 500) was 65.38 mph (105.22 km/h).^{[citation needed]}

Cooper came to dominate the formula with mass-produced cars, and the income this generated enabled the company to develop into the senior categories. Other notable marques included Kieft, JBS and Emeryson in England, and Effyh, Monopoletta and Scampolo in Europe. John Cooper, along with most other 500 builders, decided to place the engine in the middle of the car, driving the rear wheels. This was mostly due to the practical limitations imposed by chain drive but it gave these cars exceptionally good handling characteristics which eventually led to the mid-engined revolution in single-seater racing.

The 500cc formula was the usual route into motor racing through the early and mid-1950s (and stars like Stirling Moss continued to enter selected F3 events even during their GP careers). Other notable 500 cc Formula 3 drivers include Stuart Lewis-Evans, Ivor Bueb, Jim Russell, Peter Collins, Don Parker, Ken Tyrrell, and Bernie Ecclestone.

From a statistical point of view, Parker was the most successful F3 driver. Although coming to motor racing late in life (at age 41 in 1949), he won a total of 126 F3 races altogether, and was described by Motor Sport magazine (in his 1998 obituary) as "the most successful Formula 3 driver in history". Although Stirling Moss was already a star by 1953, Parker beat him more than any other driver, and was Formula 3 Champion in 1952, again in 1953, and in 1954 he only lost the title by a half-point. He took the title for a third time in 1959.

500cc Formula Three declined at an international level during the late 1950s, although it continued at a national level into the early 60s, being eclipsed by Formula Junior for 1000 or 1100 cc cars (on a sliding scale of weights).

A one-litre Formula Three category for four-cylinder carburetted cars, with heavily tuned production engines, was reintroduced in 1964 based on the Formula Junior rules and ran to 1970. These engines (a short-stroke unit based on the Ford Anglia with a special 2-valve Cosworth or Holbay OHV down-draught head, initially pioneered by Brian Hart, being by far the most efficient and popular) tended to rev very highly and were popularly known as "screamers"; F3 races tended to involve large packs of slipstreaming cars. The "screamer" years were dominated by Brabham, Lotus and Tecno, with March beginning in 1970. Early one-litre F3 chassis tended to descend from Formula Junior designs but quickly evolved.

For 1971 new regulations allowing 1600 cc engines with a restricted air intake were introduced. The 1971–73 seasons were contested with these cars, as aerodynamics started to become important.