To Issigonis, the idea of a souped-up Mini flew in the face of the car’s raison d’Ϊtre – economy above all

In the anthology of bad decisions, Dick Rowe must take the gold prize; he’s the bloke who told Brian Epstein that Decca wouldn’t sign the Beatles because ‘guitar groups are on the way out’. But the gong could so easily have gone to Alec Issigonis, who took a lot of persuading that drafting in John Cooper to build a hot Mini would be a good idea. To Issigonis, the idea of a souped-up Mini flew in the face of the car’s raison d’Ϊtre – economy above all else.

Thankfully the famously stubborn Issigonis was prepared to listen, and one of the all-time great partnerships was born, that of BMC and John Cooper.

The latter was an expert on tuning the A-series engine, and he was acutely aware of the unit’s reliability problems when the wick was turned up. Camshafts, crankshafts and timing gear were lunched on a regular basis, which is why Cooper dispensed with the standard 848cc unit. Instead, just the basic block was used, with the stroke increased to give a 997cc displacement.

Thrown into the mix were an uprated camshaft, bigger inlet valves, twin SU carbs, a three-branch exhaust manifold and domed pistons to increase the compression ratio; performance was transformed, but not at the expense of reliability.

The Mini-Cooper was an instant hit, but development didn’t stop there. From 1963 the 997cc engine was replaced by a 998cc version, based on the Riley Elf and Wolseley Hornet unit. At the same time it was clear that some people wanted an even fruitier Mini, so the Cooper S was devised. During an eight-year lifespan, this used three different versions of the A-series: initially there was a 1071cc unit, succeeded by a short-lived 970cc edition in 1964. By far the most common is the 1275cc variant, current between 1964 and 1971.

In the 21st century, the Mini-Cooper is even more desirable than it was when new. As a result, these are some of the most faked cars around – which is surely a measure of just what hot property they are. Believe it or not, nearly 120,000 Coopers of the various types were produced – but that hasn’t stopped many standard Minis being passed off as something they’re not.

That’s why you must ensure you’re buying the real thing. This guide will get you started, but you should join the Mini Cooper Register and obtain a copy of its in-house buying guide if you’re considering purchasing one. It’s also worth investing in a copy of John Parnell’s originality guide; it’s essential reading if you’re not to be duped.

Peter Barratt is chairman of the Mini Cooper Register. He comments: ‘For many years the focus has been on the Cooper S, but recently we’ve seen more interest in the standard Cooper, resulting in increased values for these cheaper cars. But you can still get a decent Cooper for little more than £5000; the S typically carries a 25% premium.

‘The cheapest Cooper S is the 1071, followed by 970cc editions; the 1275 is the one everyone wants and a really superb one of those can fetch as much as £15,000. Restoration projects start at £1800, or £3000 for an S – but check the car is genuine before buying!’

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