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AC Cobra






Cobra... The very name conjures up images of awe­some performance, evocatively-shaped haunches, a blis­tering soundtrack and a white-knuckle ride. It is, in short, a legend.

How can a car which was in production for a mere five years, and which sold only around 1, 000 examples, achieve such legendary status? The story is all the more remarkable considering the Cobra (рис. 20) grew out of a not particularly exceptional sports car, made by a tiny English firm by the name of AC, and its combination of a frail-looking ladder chassis and a brutish V8 power plant that was hardly subtle.

One name provides the answer: that of a larger-than-life Texan racer and chicken farmer called Carroll Shelby. It was he who had the vision to mate the AC Ace sports car with an American Ford V8 engine and it was Shelby who actually screwed the cars to­gether in his racing workshops in Santa Fe, Califor­nia.

Shelby had heard that AC's engine supplier, Bristol, was stopping making the 2.0-litre engines used In the Ace sports car. He got in touch with AC Cars of Thames Ditton, Surrey, in 1961 with a sugges­tion: How about using an American-made engine in the form of a 260 cu in (4260cc) V8 unit from a Ford Fair-lane? The idea of purring an American V8 engine in a European sports car was not new but no one had dared to approach the heights to which the Cobra would ascend.

AC agreed to try the idea. Amazingly, the Ace's very simple twin-tube ladder chassis was retained vir­tually unchanged, although Girling in-board rear disc brakes and a reinforcing frame for the rear suspension were fitted.

At both ends, lower wishbones were combined with transverse leaf spring upper links and telescopic dampers.

Production of the Cobra got underway in 1962. The chassis and lightweight (22.5kg) aluminium body were hand-built by AC in Thames Ditton. Most of the road equipment was then fitted and shipped to California for final assembly by Shelby, using Ford engines, close ratio Borg-Warner four-speed gearboxes and strengthened drive shafts.

The Cobra first appeared on the Ford stand at the 1962 New York Auto Show, where it caused a sensa­tion, an impact which was reinforced by a number

 

 

Рис. 20

 

of high-profile road test reports. Sports Car Graphic de­scribed the Cobra as " one of the most impressive pro­duction sports cars we've ever driven", adding that its acceleration was " explosive". Their official road test recorded the astonishing times of 0-60 mph in 4.1 sec­onds and the standing 1/4 mile in 12.9 seconds. Those figures can put to shame most current supercars, let alone the sort of machinery which was available in 1962.

The secret of the Cobra's performance was not a massive power output - it had a ‘mere’ 260 bhp to begin with - but its light weight. The Cobra measured only 151in (384cm) long, so weight was kept down to 20201b (916kg), producing a power-to-weight ratio of 258 bhp per ton - better than the contemporary Ferrari Testa Rossa.

In America, the model was generally known as the Shelby Cobra but European markets always had cars badged as the AC Cobra, and later just AC 289 Sports. The advertising presented it as the perfect match of British styling and craftsmanship with American power and reliability.

Right from the start, it was offered with compe­tition options for owners who wanted to take their cars racing. Owners could buy roll hoops, racing seats, cut-down windscreen, extra vents and a whole host of engine options. Racers would soon be following in successful footsteps for the Cobra was the first British finisher in the 1963 Le Mans, scored many vic­tories in American SCCA events and met with success in numerous European races.

On the back of its racing pedigree, the Cobra sold well, especially in America. It was actually cheaper than the old Bristol-powered Ace had been, selling for around the same price as the poorer-performing Jaguar E-Type. Shelby was forced to move to bigger premises to cope with the growing demand.

In alliance with Shelby, Ford itself ironed out many of the Cobra's problems. A lot of work went into balancing the chassis. Rack-and-pinion steering replaced the archaic worm-and-roller system. Then Ford offered Shelby their bigger 289 cu in engine.

This was merely a stepping-stone to the ultimate Cobra: the 427 of 1963. Conceived as a giant-killing race-winner, it was essentially a Cobra fitted with a big block 427 cu in (6997cc) V8 from the Ford Galaxie 500. The 271 bhp Cobra 289 was already a performance legend, so the impact of the 425 bhp Cobra 427 was go­ing to be shattering. And th at was in standard tune -with the right tuning gear, there was potential for that to go up to 480 bhp and beyond.

Two examples were completed with Paxton super­chargers and claimed to deliver no less than a fright­ening 800 bhp.

To cope with the extra power, the chassis was completely redesigned. The basic ladder frame layout remained but the tubes were far thicker and the sus­pension towers were now tubular affairs, not fabri­cated sheet metal.

At last, the old leaf spring suspension gave way to coil spring dampers and double wishbones, refined by Ford Engineering to be fully adjustable. Larger brakes, beefed-up drive shafts and extra cooling com­pleted the picture.

The 427 also looked more muscular. Only the bon­net and doors stayed the same - everything else had been pumped up to accommodate much fatter 8.15in (207mm) tyres.

The 427 did not have much of a competition life, because by 1965 it would have clashed with Ford's own СТ40. Nevertheless, a Semi-Competition (S/C) model was offered to private buyers as " the fastest production car in the world", with a top speed of around 165 mph and a 0-60 mph time of 4.0 seconds. One 427 managed to accelerate to 100 mph and back to zero again in just 13.8 seconds.

Safety and environmental legislation killed the Cobra in 1968. AC tried to update the concept with the Frua-bodied AC 428 but this did not last long in the fuel crisis of the 1970s.

All types of Cobra are extremely rare and sought after today, with authenticated 427s commanding prices well in excess of £ 150, 000. With so few originals ever made, it is hardly surprising that a vast industry has sprung up dedicated to making AC replicas.

As well as literally dozens of companies produc­ing fibreglass copies the world over, an official AC Cobra Mk IV has been manufactured from 1953 by Autok-raft, which is the only company legally entitled to use the AC name.

Carroll Shelby himself launched a controversial new Cobra in the 1990s, which he said was based on chassis left over from the 1960s. However, none of the replicas could ever hope to match the raw magic of an original 1960s Shelby-built Cobra, one of the greatest motoring legends of all time and certainly one of the most exhilarating.






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