AC Cars Group Ltd. is a British specialist automobile manufacturer and one of the oldest independent car marques in Britain.
The first automobile from what would eventually become AC was presented at the Crystal Palace motor show in 1903; it was a 20HP touring car and was displayed under the Weller name. The Weller Brothers of West Norwood, London, planned to produce an advanced 20 hp car. However, Portwine (their financial backer) thought the car would be too expensive to produce and encouraged Weller to design and produce a little delivery three wheeler. Weller did so, called it the Auto-Carrier, and a new company was founded and named Autocars and Accessories; production started in 1904. The vehicle caught on quickly and was a financial success. In 1907 a passenger version appeared, called the A.C. Sociable. It had a seat in place of the cargo box.
The company became Auto Carriers Ltd in 1911 and moved to Ferry Works, Thames Ditton, Surrey - at this time they also began using the famed "AC" roundel logo. Their first four-wheeled car was produced in 1913; it was a sporty little two seater with a gearbox on the rear axle. Only a few were built before production was interrupted by the first World War.
During the Great War, the Ferry Works factory produced shells and fuses for the war effort, although at least one vehicle was designed and built for the War Office. At the end of the First World War, AC Cars started making motor vehicles again, designing and building many successful cars at Ferry Works, as well as expanding into an old balloon factory on Thames Ditton High Street.
After the war, John Weller started on the design of a new overhead cam 6 cylinder engine. The first versions of this design were running by 1919. The Weller motor would be produced through 1963; it is possibly the second-longest-lived production motor in history after the Volkswagen boxer.
In 1953 the firm began production of the AC Ace, a lightweight chassis designed by John Tojeiro with the venerable Weller-designed 2-Litre engine. Soon after, car dealer and racing driver Ken Rudd fitted his own competition Ace with a pre-war BMW-designed, Bristol-produced 135 bhp (101 kW) six-cylinder engine. This combination was put into production as the AC Ace-Bristol in 1957. In this form, the car raced at Le Mans in 1957 and 1958.
In 1961, Bristol stopped producing their own engines - and once again, Ken Rudd came to the rescue, suggesting that AC use a 6 cylinder engine from the Ford Zephyr. These engines when fitted with the Raymond Mays twelve-port alloy head and Weber carburetors could be made to produce a safe 170 bhp (127 kW) and a 125 mph (201 km/h) top speed.
In 1962 AC was approached by Carroll Shelby to use a small block Ford V8 engine in the Ace chassis, producing the AC Cobra. Shelby needed a car that could compete with the Chevrolet Corvette in US sports car racing. The resulting Cobra was a very powerful roadster, and it is commonly blamed for the introduction of the 70 mph (113 km/h) limit on British motorways. While this was a major factor in the decision, after a coupe version was caught doing 196 mph (315 km/h) during a test run, a then-recent spate of accidents under foggy conditions also helped the introduction of the limit.