AC Shelby Cobra Mk I 260
Model history:
While racing in Europe and North and South America throughout the 1950s, Carroll Shelby cherished one dream; building the world's fastest sportscar. By 1956 he had already come up with a name for his car, it would be named Cobra. Soon after his 1959 24 Hours of Le Mans victory for Aston Martin, Shelby was struck by heart problems. Reluctant to do so, he was forced to give up motor racing as a driver. This did give him time to make his dream come true.
Early in the 1950s John Tojeiro had designed small a sportscar, which was sold under the AC Ace name. Installed in the simple but effective tubular chassis was an AC six cylinder engine and later also Bristol and Ford straight sixes. Its lightweight chassis and body, and effective engine made the Ace a moderately successful racer. When Bristol announced that the 2 litre engine would be phased out, AC was left without an engine to power the Ace. Previous attempts to install other engines, like American V8s had failed miserably and the end of the Ace production was announced.
When Shelby read about the end of the AC Ace, he immediately contacted AC and his long time associates Ford. He convinced AC to continue constructing the Ace and Ford to supply special versions of their Fairlane engine for installation in the AC chassis. Shelby flew over to the UK to supervise the construction of the prototype chassis, which featured modifications designed by Shelby to ensure the hybrid would be drivable
Although the displacement of the Ford '260' V8 was more than twice as large and the initial 260 bhp output almost twice as large as the Bristol's, the Ford unit weighed less. Main difficulty in incorporating American V8 engines was their rather high torque figures. The rear-end needed considerable modifications to handle the torque produced by the Ford. With the beefed up rear suspension, the AC chassis took to the Ford V8 engine surprisingly well and after extensive tests 100 chassis/bodies and Ford V8s were ordered. Shelby's Cobra was born!
The V8 Ford engines were derived from the ones used in the Fairlane and Fairlane 500, but they were delivered to Shelby in a somewhat 'tweaked' form. Breathing through a single Holley Carburettor and fitted with 'hotter' cams, solid tappets and larger ports, the V8 was good for around 260bhp. For competition use Shelby modified the engine even further. With an increased compression ratio and breathing through four twin-choke Webers figures of 335 bhp could be achieved, with the engine revving up to 9000 rpm. Stunning performance was the result of this very powerful engine, which is reflected by the acceleration and top speed figures. Had Shelby succeeded in building the world's fastest sportscar?
In the mean time, the world's largest manufacturer and Ford's biggest competitor, General Motors worked intensively on building their fastest GT-racer yet. Dubbed Sting Ray, the fastest Corvette to date was set to make its debut at the 1962 Riverside 3-hour race for Grand-Touring cars. Coincidently Shelby's workshop was around the corner of the Riverside track and his competition Cobras were about ready to make their debut as well. So in a weird twist of fate, both GM's and Ford's latest racers made their debut in the same race. In qualifying Shelby took the wheel of one of the two Cobras entered and shocked the crowd and even more so GM's racing division by lapping over four seconds faster than the fastest Sting Ray. In the race Bill Krause had built up a lead of over 30 seconds in the first 30 minutes. He was forced to retire when a wheel came off and in doing so he handed the victory to one of the Sting Rays. A legend was born that day, but it wasn't the Sting Ray!
Vowing to decimate the Sting Rays in the following season, Shelby and his Cobras took part in the first US manufacturers' championship in 1963. The Cobra's dominance was total and Shelby took the title with 111 points over Ferrari's 28 and Chevrolet's 19. All but one of the seven races of the championship were won by a Cobra. During the season, the Cobra received a full FIA homologation, which made it eligible for the World Championship races. Around the same time a new Ford engine became available; the 4.7 litre '289', which in competition form was good for at least 340 bhp.
Two of the new FIA homologated 289 engined cars were prepared for the most important round of the World Championship; the 24 Hours of Le Mans. Ford was not very cooperative, but the hardtop equipped cars were ready in time to be handed over to AC Cars in the UK and Ed Hugus representing the US. In the high speed race the roadster's biggest problem was its poor aerodynamics, which limited is top speed considerably. Eventually the British car finished seventh overall and fourth in class behind three Ferrari 250 GTOs. The American car was forced to retire after one of the con rods pierced the engine.
Although the Cobra's first outing at Le Mans did not prove as successful as its American campaign, it did learn the team a valuable lesson. In the 1964 running a special low drag coupe version was campaigned, which solved the roadster's problems and ended Ferrari's dominance in the GT class.
Chassis: CSX2000
Built late in 1961, chassis CSX2000 is the very first AC Shelby Cobra built. It was first run in England and subsequently used as a development vehicle before entering the show circuit. Painted yellow, it debuted at the 1962 New York Auto Show where it was one of the absolute stars. Repainted before almost every appearance, it was shown at events around the country until September. In between shows, the prototype was also inspected by the FIA to get the all-important homologation.
Since then it has been carefully preserved by Carroll Shelby himself. Rumour has it that he has turned offers of well into the seven figures for this, his firstborn and a unique piece of American road racing history. Still in completely original condition, CSX2000 has been regularly displayed in at shows and museums. In recent years, it has only made rare appearances. The Cobra prototype is seen here at the 2010 Quail, a Motorsports Gathering where 45 years of the Shelby Mustang was celebrated.