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The Birth of the MINI COOPER
When the Mini was designed by Sir Alec Issigonis back in the late 50’s, he would not have envisaged that such a humble little car would become a giant killer on the racing and rally scene. Nor would he have thought that it would still be in production, with the same basic shape, forty years later.
If the Mini was born because of the brilliance of Issigonis, the Mini Cooper owes its birth to the genius of John Cooper, already a World Champion racing car constructor when the Mini was released in 1959. The Cooper Formula Junior cars were powered by modified BMC A-series engines bought from the BMC plant. At the time Issigonis was technical director.
Cooper was well aware of the Mini’s development and its racing potential. He persuaded BMC to loan him an early production version so he could carry out performance modifications. The prototype Mini Cooper which resulted, featured a 997cc Formula Junior engine and 7inch disc brakes on the front.
The new car was well received by those who test drove it. Cooper sensed that he was on to a winner, so he sought the support from Issigonis to persuade BMC to produce the 1000 cars required to meet group 2 homologation racing regulations. Issigonis refused to help, as the Mini as he saw it, was never designed to be a sports saloon. John Cooper appealed to the then managing director of BMC and although sceptical that 1000 cars could be sold, agreed and also granted Cooper a royalty for every car built.
Production of the 997 Mini Cooper began in July 1961. Apart the duo-tone paint, special grille and badging, there was little to distinguish this hot Mini from the more sedate 850. The big difference was of course in the engine – with twin SU carburettors – and the upgraded running gear. Other changes were the 100mph speedo, oil and temperature gauges in a revised oval binnacle and a remote gear change lever. In all, 24,860 Cooper 997’s were produced before it was replaced by the shorter stroked 998cc version in November 1963.
Knowing that the 997 engine had reached the end of its development potential and that to keep both the Mini and Junior Formula cars competitive on the racetrack, Cooper was keen to move up into the 1100cc class. The long 81.28mm stroke of the 997 engine was not conductive to high revving and increasing the bore to a planned 64.58mm left very little between cylinders, so it was obvious that a re-designed engine was required.
The development of the new engine was undertaken. It featured ‘siamesed’ bores, 2inch diameter big-end journals, nitrided crankshaft and a big valve cylinder head. The re-designed engine was unlike any other A-series engine produced at the time.
Just as the 997 engine heralded the birth of the Cooper, this 1071cc engine was to be the launching pad of the Cooper S, which was announced in March 1963. Production got under way in late April.
The 1071’s free revving 68.2mm short-stroke power unit delivered 15bhp more than the Mini Cooper, giving it a top speed around 95mph which was good for a car of that size at that time. The braking system was upgraded to cope with the extra speed with 71/2 inch discs on the front and boosted by a hydrovac servo. The only difference between the Cooper and the Cooper S were the addition of the S badge on the bonnet and boot, ventilated wheels and a 120mph speedo. Options available for the 1071 included an oil cooler, sump guard, close ratio gears and right hand tank.
Before the year was out 2 new Cooper models were released and Paddy Hopkirk and Henry Liddon became national heroes after winning the Monte Carlo Rally in 33EJB, a 1071 Cooper S.
From June 1964 to April 1965, the Cooper S 970cc version was introduced. The power unit had the standard 70.6mm bore common to all Cooper S models, but the 970S had an ultra short stroke of 61.9mm, giving it a phenomenal revving capability. Only 963 cars were made.
In March 1964, the 1275cc Cooper S was launched and was immediately a runaway success. The long stroke of 81.28mm, the same as the 997cc Cooper, gave a distinctive note to the exhaust, pushed it from 0 to 60mph in 10.9 seconds and gave it a top speed of nearly 100mph. But few cars are perfect from birth and the 1275 S was no exception. Its alarming thirst for oil, over heating and high fuel consumption meant that an Oil Cooler and right hand tank were much used options and became standard equipment from January 1966.
With the launch of the 1275cc S, the Cooper had come of age. On 28th August 1964 the 1071cc S ceased production after rolling out 4031 units, just before hydrolastic suspension was introduced on the 1275 S in September 1964.
The Mini Cooper’s competition successes are unequalled around the world. Its phenomenal handling and performance enabled it to dominate in all forms of motor sport through the 60’s.
The merger of BMC with Leyland in 1968, came at a time when the corporation was in deep financial crisis, and a ruthless rationalisation program began. All badge engineering ceased and with it disappeared the long links with the Cooper name.
The Mini Cooper was re-launched by Rover in on 10th July 1990.
Information was sourced from John Parnell’s book “Original Mini Cooper & Cooper S”.
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