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’etre – 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 well versed on the black magic involved to successfully tune the fairly weak A-series engine. There were of course many problems, with camshafts, crankshafts and timing gear chewed up regularly. In the end, it was these issues that eventually the lead to Cooper ditching the standard 848cc engine. While the block was retained, the stroke was increased resulting in a 997cc capacity.
With the increased displacement came some carefully balanced upgrades. A spikier camshaft, bigger inlet valves, twin SU carbs, a three-branch exhaust manifold helped the breathing, while domed pistons raise the compression ratio. Performance was significantly increased, while reliability didn’t suffer too much.
The Mini-Cooper was an instant hit, but development didn’t stop there. From 1963 that original 997cc became obsolete, swapped out with an updated 998cc from the Riley Elf - with a few Cooper tweaks.
While the standard Cooper evolved and improved though, it turned out that there was a significant demand for something with a bit more performance. This was satisfied in the form of the Mini Cooper S, the car we’re looking at in this guide
Which one to buy?
Highly coveted today, there were three major variations of the S over it’s lifespan. Rarest today are the 970cc versions which followed on from the initial 1071cc cars. The best remembered, and by far the most common are the 1275cc cars, utilised between 1964 and 1971.
Due to the serious desirability and collectability of genuine Cooper models, combined with serious values, there are many counterfeit Coopers around so it pays to do your homework. With almost 120,000 Coopers of all flavours produced, it can be difficult to spot a well-produced fake.
Your best chance to avoid being stung is to research any potential purchase thoroughly. Know exactly what you are looking at, and contact the Mini Cooper Register for extra help. 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.
Performance and specs
Engine 1071cc, four-cylinder
Power 70bhp @ 6200rpm
Torque 62lb ft @ 4500rpm
Top speed 90mph
Fuel consumption 29.4mpg
Gearbox Four-speed manual
Dimensions and weight
Kerb weight 686kg
• Early on, it’s fair to say that most Coopers would have been driven hard, and many are still enjoyed enthusiastically to this day. While they are built to take a certain amount of punishment, the engines do develop a number of issues.
• A smokey, oil-burning A-series is not uncommon and is something that will affect most at some point. The main culprit is worn piston rings and bores. If the top end of the engine sounds overly noisy, then the rocker gear needs attention.
• Overheating is also a potential problem, although this affects standard Cooper models more than the more substantially-cooled S.
• Most rough running can be traced to badly adjusted carburettors. When they are worn out or incorrectly balanced it can make a cooper feel rather unpleasant to drive. Sorting is a cheap and relatively easy process, as there’s still plenty of mechanics skilled in the art of setting up these carbs.
• Cylinder heads do have a habit of cracking between the valve seats. As the Cooper came with larger valves, cracks can form if and when the engine gets too warm. These cracks might not be evident, however a badly misfiring engine could be a warning sound.
• The Mini’s gearbox has always been known as fragile, even in standard form, and the Cooper is no different. Sharing its lubricant with the engine means that it needs special attention.
• Going without a synchro on first gear until 1968, all models featured a four-speed transmission. Some may have been converted to five-speed today, while earlier cars might have also been retrofitted with a later all synchromesh ‘box.
• If the shit doesn’t feel quite right, it’s likely that the nylon bush has become perished, but this is a cheap and easy fix.
• Driveshaft rubber couplings also have a limited lifespan, especially if they are contaminated with engine oil (most have some form of leak). Post-1966 S models used Hardy-Spicer needle-roller couplings which are much stronger, but all other cars need regular coupling replacement, at £150 a time.
• It depends what age of car you’re look at as to which suspension set-up you get should be seeing. Early cars got the standard rubber cones and telescopic dampers, but post-September 1964 Coopers got the more advanced Hydrolastic set-up. The company reverted to the classic set-up as of 1969.
• Many Hydrolastic cars have been converted to the more simple set-up but it’s a difficult job to put it back to standard, so ensure you are happy with what you’re buying.
• Standard rack-and-pinion steering should feel direct and responsive, as one of the car’s defining characteristics. Sloppiness of an inconsistent feeling is a sign that a new rack is needed. Thankfully, this is a relatively cheap and easy job to carry out, with spares availability extremely good.
• With such tiny wheels, it’s no surprise that the Cooper’s brakes are equally diminutive. If the car is driven hard, they struggle to cope, so worn and scored discs are quite normal. With virtually everything being available to rebuild any Cooper braking system (standard calipers are obsolete), there’s no excuse for poorly anchors and in this case safety should come before originality.
• Standard Minis featured drums all round, while the Cooper had seven-inch discs at the front; S discs were half-an-inch greater in diameter. Upgrades to S specification are common, and usually seen as acceptable – but even this may not be enough to rein in a very hard-driven car.
• Rust is a serious issue for every Mini ever built, and the Cooper is just as prone. Virtually every panel is susceptible to the tin worm, and it can seriously affect the value - so do be thorough with your checks.
• The floorpan and bulkhead should be first on your checklist, followed by the front wings, and all outer panels – paying special attention to the seams. Rear wings rust through, and the rain gutters can also cause issues.
• It’s likely that the sills will have been replaced on more than one occasion, so check them for any corrosion or dodgy patches. Doors and bootlids tend to rust just as badly as the rest, so again - check every panel!
• Out of everything, the A-posts are generally considered to be the most difficult area for repairs, so take a good poke around this area.
• Interior trim was varied and extensive, and incorrect parts are common. The various Coopers featured all sorts of different trim and instrumentation combinations.
Mk1, Oct 1961-Jan 1964: Chassis nos. prefixed C-A2S7 (Austin) or K-A2S4 (Morris), engines prefixed 9F, 55bhp, 54lb ft from 997cc. 24,860 made.
Mk1, Jan 1964-Oct 1967: Chassis nos. as above, engines prefixed 9FA, 55bhp, 57lb ft from 998cc. 64,224 made.
Mk2, Oct 1967-Nov 1969: Chassis nos. prefixed C-A2S8 (Austin) or K-A2S6 (Morris), engines prefixed 9FA, 55bhp, 57lb ft from 998cc. 16,396 made.
1071S, Mar 1963-Aug 1964: Chassis nos. prefixed C-A2S7 (Austin) or K-A2S4 (Morris), engines prefixed 9FSAH, 70bhp, 62lb ft from 1071cc. 4031 made.
970S, Mar 1964-Jan 1965: Chassis nos. as 1071S, engine prefixed 9FSAX, 65bhp, 55lb ft from 970cc. Just 963 made.
1275S, Mar 1964-Jul 1971: Chassis nos. as 1071S until introduction of Mk2 Mini in Oct 1967. From then, prefixes are C-A388 (Austin) and K-A2S6 (Morris); from arrival of Mk3 bodyshell in March 1970, cars carry B-20-D prefix. 1275S engines have 9FSAY prefix, 76bhp, 79lb ft from 1275cc. 14,313 made, with another 6329 Mk2s and 19,511 Mk3s built.
Owners clubs, forums and websites
Summary and prices
All Coopers are great to drive and unlikely to depreciate, but the pick is the Mk1 1275S, built between April 1964 and September 1967. With a perfect blend of performance, relative availability and charming looks thanks to the Mk1 bodyshell, this is the Cooper that has it all.
As long as you buy a good one, you’re pretty much guaranteed to see your Cooper go up in value. But as soon as you slide behind the wheel, all thoughts of seeing the car as an investment will go out the window.
This really is a car that redefines the joy of driving – and that’s in standard form. Thanks to its iconic status there’s no shortage of specialists willing to sell you bits to make the Cooper even better to drive, and you won’t need to spend a fortune either.
For many years the focus has been on the Cooper S, but the standard Cooper is now also significantly sought after, resulting in increased values for these cheaper cars. But you can still get a decent Cooper for little more than £12000; 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 £35,000 today. Restoration projects start at £3500, or £10,000 for an S – but check the car is genuine before buying!