1962
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The AC Cobra was a powerful Anglo-American sports car built in the 1960s. It was far from the first car to combine a lightweight European chassis and aluminum body with a big American V8 engine, but it is possibly the most famous. The later, larger-engined cars are still among the highest-performing road vehicles ever sold.
Like many British specialist car manufacturers, AC Cars had been using the smooth, refined Bristol straight-6 engine in its small-volume production, including its AC Ace 2-seater roadster. Unfortunately for AC and other manufacturers, Bristol decided in 1961 to cease production of its engine and instead to use Ford V8 engines. Thus, AC had a car without a future source of power. Into this void stepped American ex-racing driver Carroll Shelby, who in September 1961 airmailed AC a proposal to ship its engineless cars to Shelby's California works to be fitted with American V8s. Shelby had previous experience with Anglo-American hybrids, having raced an Allard.
AC agreed, provided a suitable engine could be found. It was, in the form of Ford's 260 HiPo (4.2 litre) engine - a lightweight, thin-wall cast small-block V8 tuned for high performance. In early 1962, the first engineless AC Ace was air-freighted to Shelby's Los Angeles facility, where it was fitted with an engine and transmission in less than eight hours and taken out on test. Carroll Shelby claims the name "Cobra" came to him in a dream, and the car was given that name.
1999 AC Cobra 427It proves a great performance success; the automobile had originally been designed by Shelby with the intention it would be a "Corvette-Beater" and at nearly a ton less than the Chevrolet Corvette, the lightweight car did just that. Production proved to be less easy; the AC chassis needed extensive work to take the Ford drivetrain, and at first cars were slow to be produced. Soon, a larger but similar Ford engine, the 289 (4.7 L) V8 was fitted. Shelby Cobras began an extensive racing career with this engine, which boosted power from 165 to approximately 270 horsepower (123 to 201 kW) and gave it a new top speed of 140 mph (225 km/h).
1964 saw an even larger engine fitted; Ford's famed 427 in³ racing engine (7.0 L) developing 485 brake horsepower (362 kW) and attaining a top speed of 163 mph (262 km/h). (Tom McCahill, in "Mechanix Illustrated", famously described the vehicle as "hairier that a Borneo gorilla in a racoon suit"). Even more extensive rework of the AC design was needed to accomplish this; the big-block FE-series engine was much too large to fit in the standard engine bay. The front tires were moved outward, with extended wheel-arches to cover them, and a new coil-spring suspension was designed.
Some Shelby Cobras were fitted with Ford's 428 in³ (7.01 L) engine, a less powerful engine despite the nominal increase in displacement, intended for road use rather than racing.