Austin/Morris Mini Cooper
Austin/Morris Mini Cooper Published: 28th Aug 2018 - 0 Comments - Be the first, contribute now!Fast Facts
- Best model: Cooper S 1275
- Worst model: Anything fake
- Budget buy: Mk2 Cooper 998
- OK for unleaded?: No – you need an additive
- Will it fit in the garage? (mm): 3048x1410mm
- Spares situation: Very good
- DIY ease?: No problem
- Club support: Excellent
- Appreciating asset?: Yes, but not by as much as you might think
- Good buy or good-bye?: Proof that the best things come in small packages

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Mini with the most is as appealing now as ever. Terrifi c point-to-point enjoyment is tempered by lack of comfort and refinement.
It’s not always true that less is more. Take the Mini Cooper for example, which in standard form is a riot to drive in any situation. Whether you’re cruising urban streets or tearing up a mountainside, the Mini is immense fun. But in standard form the Mini isn’t exactly over-endowed with grunt – something that John Cooper spotted almost 60 years ago. He reckoned that a Mini with more power would be just what the market wanted and despite Alec Issigonis having severe reservations about the idea, a hotted-up Mini was introduced in 1961.
Suddenly, the car that had been launched with economy at its core now had a focus on performance, and punters couldn’t get enough; when the even hotter Cooper S arrived two years later, that proved just as popular. Over the next decade almost 145,000 Cooper-badged Minis would be made, proving that far from being mutually exclusive, performance and economy go together to create a very desirable package indeed.
Dates to remember
Sep 1961 The Mini Cooper arrives with a 997cc engine featuring twin SU HS2 carbs and a compression ratio of 9:1 (8.3:1 for some overseas markets). Engine prefix: 9F-SA-H (high compression), 9F-SA-L (low compression). The engine block (with removable tappet chest covers) has 12A 204 cast into the back, 12A 497 for later 997s. Early cylinder heads are the 12A 185 casting, later versions are 12G 202. Remote gear change, close-ratio gears (in a 22G 68 gearbox casing), 3.76:1 final drive ratio, seven-inch front disc brakes, duotone paint with a contrasting duotone interior borrowed from the Mini Super, except 100mph speedometer and ‘Cooper’ exterior badging.
Mar 1963 The 1071 Mini Cooper S débuts with a revised Formula Junior cylinder block (AEG 151 casting no. on back), big-valve version of the 12A 185 cylinder head with an extra stud and bolt at each end; later cars adopt the AEG 163 cylinder head. Compression ratio 9:1. Valves have double springs and solid forged valve rockers. Engine prefi x: 9F-SA-H. Twin SU HS2 carbs, EN40B steel Nitrided crankshaft, duplex timing chain. Bigger (7.5-inch) front disc brakes with Lockheed servo. Close-ratio gears in a 22G 190 gearbox casing, 3.76:1 final drive ratio, remote gear change, colour schemes and interior as per 997cc Mini Cooper, except 120mph speedometer, ventilated wheels, exterior Cooper badging supplemented with the letter ‘S’. Optional factory oil cooler and right-hand fuel tank.
Nov 1963 997cc Mini Cooper engine replaced by 998cc powerplant based on the Riley Elf and Wolseley Hornet unit (12A 497 cast on the back). Early cars have 12G 206 cylinder head, most have the 12G 195 unit. Power output remains unchanged. Duotone colour and trim features as before.
Feb 1964 1275cc Mini Cooper S enters production. Same as 1071cc model but with taller engine block (AEG 312 casting no. on back) with longer throw crankshaft. Compression ratio 9.75:1, engine prefix: 9F-SA-Y, close ratio gearbox uses 22G 333 casing and a final drive ratio of 3.44:1 as standard.
Jun 1964 970cc homologation special goes into production. Just 963 are built. Shares same cylinder block and gearbox as 1071cc Mini Cooper S but with high-revving ultra short stroke configuration. Compression ratio 10:1, engine prefix: 9F-SA-X.
Aug 1964 1071cc Mini Cooper S ceases production.
Sep 1964 Revised SN4417 Smiths speedometers introduced with orange warning lights and calibrated to 105mph for 998cc Cooper and 130mph for 1275cc Cooper S.
Oct 1964 Hydrolastic suspension replaces rubber cone suspension across the Mini range, instruments now operate through a voltage stabiliser, revised sun visors and rear view mirror, door courtesy light switches introduced.
Apr 1965 970cc Mini Cooper S ceases production.
Sep 1967 MkII replaces MkI with redesigned grille and surround, bigger rear window, and larger tail light clusters. Chassis numbers prefixed C-A2SB (Austin) and K-A2S6 (Morris). Engine number prefixed 9FD-SA-H (998cc Cooper) and 9F-SA-Y (1275cc Cooper S). Plain black interior becomes standard at the end of September 1967. Instrument dials given redesigned faces and rounded bezels.
Oct 1968 Four synchromesh gears introduced. engine prefixes change to: 9F-XE-H (998cc Cooper) and 9F-XE-Y (1275cc Cooper S). The Cooper and Cooper S gear ratios are now housed in the rationalised 22G1128 gearbox casing. Mar 1969 998cc Cooper engine prefixes change to: 99H 377CH (dynamo) and 99H 378CH (16ACR alternator).
Nov 1969 The 1275GT replaces the 998cc Mini Cooper and the AEG 163 Cooper S cylinder head is superseded by the more reliable big-valve 12G 940 1805 cylinder head.
Mar 1970 The Cooper S MkIII supersedes the MkII, with concealed door hinges, wind-up windows and monotone exterior colour schemes. Chassis prefi x XAD1, commission no. prefi x: N20D, engine prefi x: 12H-397-F (dynamo) or 12H-398-F (alternator).
Jun 1971: MkIII Mini Cooper S production ceases.
Driving and what the press said
Surely everybody knows Minis and either loves or loathes them – there’s still no half measures almost 60 years since launch. They’re a road legal rollerskate that’s a sort of masochistic fun for four.
By the time the Cooper came along, motorists were warming to the quirky and cute little Mini but the press was always sold on the sportier type.
Although hardly shattering even back then Autocar said that the performance (0-60mph in 18 seconds!) was unheard of out of a 1-litre engine and the Cooper was “an astonishingly fast means of reaching B from A”. The weekly went further and predicted that such small performance cars, such as the Austin Seven Cooper it tested, will be in increasing demand due to density of traffic (in 1962!). Rival Motor’s verdict on the Cooper S, with 0-60 clipped to 1.9 seconds, was “ this is one of the most inexpensive, most versatile and most exhilarating road cars ever offered”.
When Sporting Motorist first tried a Mini Cooper in 1962, it was clear that this was more than just a warmed-up regular Mini: “Increased performance was but a part of the overall improvement which makes the Cooper models very desirable motor cars. Major change from the driver’s point of view is the remote control gear change lever which is sited in the centre of the car just in front of the seats, so that the reach required for the normally angled lever is eliminated. The new change is also much more positive and the close-ratio gears fitted to this model also make for fuller use of the engine’s potential” was the judgement.
The cabin improvements were welcome (extra instruments, comfier, more supportive seats, more upmarket two-tone trim) but of course it was the extra performance that was the headline feature. “The performance of the 997cc engine is a marked improvement on the 850cc version. The acceleration imparted by this engine is truly remarkable for a small car… the 0-50mph figure of 11.5 seconds struck us as being the most impressive and certainly the most useful… The finish and performance is such that one often gets the impression of driving a quality GT car, but the noise level at high speeds soon dispels this”.
If Sporting Motorist was keen on the Cooper, predictably it was even more enthusiastic when the Cooper S was released. When reviewed in 1963 the magazine wrote: “The S really denotes Something; it is a real advance on the 997cc Mini Cooper which was introduced almost two years ago. We have considerable experience of the Mini Cooper and already it is clear that the bigger-engined version, with 70bhp as against the 55bhp for approximately the same car and all-up weight, is appreciably nippier up to 60/70mph.
“Our two outstanding impressions so far are the smoothness of the engine and the remarkable power of the Lockheed disc-and-drum brakes with Hydrovac servo assistance. Only moderate pedal pressure is necessary at any time and the car pulls up all-square whether the road surface is wet or dry”.
More than half a century on the refinement levels and the ability of the braking system aren’t seen in quite the same light, but such is the march of progress. The final word goes to John Rhodes, who was reckoned to be the most talented circuit racer of Mini Coopers in period. When he was asked why he drove faster than anybody else he replied: “Because the brakes were so poor when I first drove one, I arrived at my first corner far too quickly and the car just went round”.
Values and marketplace
Values for Minis has gone through the roof, even for ordinary versions let alone the Coopers. The Mini Cooper Register’s John Parnell comments: “Forget about the headline-grabbing cars with very high prices; these are best consigned to the world of those with more money than sense. Most Mini Cooper enthusiasts live in the real world, even if the current market doesn’t seem to reflect that.
“When buying a Mini Cooper or Cooper S you should consider only two types of car: the basket case that’s complete but requires full restoration or a properly restored pristine example featuring most, if not all, of the correct original detailing. The riskiest cars to buy are those that are still roadworthy but require TLC. Such a car can still carry a heavy price tag, and yet what was described as “needs some attention to make perfect” can quickly escalate into a full-scale restoration costing thousands. At least with a non-runner wreck you already know that a lot of work (and expense) lies ahead of you.
“As with most classic cars, the presence of factory originality and a nice thick file showing long-term continuous ownership history are the two elements that really add value. And sometimes a time-warp vehicle that is completely sound but showing age-related patina can be worth a lot more than one that has undergone a nut-and-bolt rebuild.
“The most desirable models are the MkI 1071, 970 and 1275 models (down to personal preference); many enthusiasts like the extra grunt offered by the 1275cc models while the most affordable cars are the MkII 998cc models.
“Parts availability is generally very good but genuine items like speedometers and good Cooper S engine blocks and gearbox casings are hard to come by and fetch very high prices. Some gearbox components are also becoming scarce even for four-synchro boxes”.
Restoration project Cooper Ss turn up occasionally and sell at auction for eye-watering (and headline-grabbing) prices. In recent years many cars have been brought back from the US but some people baulk at converting them to right-hand drive as it affects originality and hence value. The 997cc cars have a strong following in historic racing which has pushed up prices; far more 998cc cars (MkI & MkII) have survived making them good entry-level cars and you have a better chance of fi nding one of these, and at a more reasonable price, than a MkI or MkII Mini Cooper S.
Just 1568 MkIII Cooper Ss were built but the survival rate is high. Seen as a watered down model and boringly plain in appearance, they’re as potent as earlier 1275cc cars and have a much-deserved following. Examples regularly come up for sale and because most of their trim was pared back and shared with other contemporary Mini models, they’re much easier (and cheaper) to restore to factory spec. Many Cooper parts have been remade, quite a few to a better standard than original; the demand for new old stock items has driven prices to stratospheric levels, which is why many parts are now being remade.
Parnell concludes: “These early Coopers are still out there but fewer owners seem prepared to take them to shows possibly because of the expense they may have gone to restore them and a reluctance to expose them to the dangers of the open road.
“What you will find is far greater numbers of 1990- 2000 Rover Mini Coopers, many of which are still used on an everyday basis. Even though prices of these are creeping up, they offer the right level of nostalgia and yet all of the trappings (comfort, safety, and quietness) of a modern day car. You will find a lot more of them for sale too”.
Improvements
The Cooper and Cooper S are some of the most collectible classics around, which is why more and more owners crave originality. If you do decide to uprate in any way, retain any original parts so if you come to sell the car you have those factory bits to pass on.
In period, an entire industry sprang up to service the needs of Mini owners keen to pep up their cars. Downton was one of many tuners, which had to compete with the likes of Speedwell, Alexander, Taunus, Stewart & Arden, Broadspeed and the factory BMC Special Tuning among many others. These focused on spicier camshafts, reworked cylinder heads, bigger carburettors, big-bore exhausts – all of the traditional methods of tuning that have now been overtaken by chipping and remapping and even crossflow alloy cylinder heads – avalable from Webcon – if you want to shell out some £1200 – the Mini market is as buoyant as ever with new ideas constantly surfacing.
While many of these upgrades are still worthwhile it’s essential that you don’t damage the Mini’s essential driving characteristics, compromise reliability or destroy your car’s value. For the full picture it’s worth investing in a copy of Tim Mindy’s Mini Performance Manual, published by Haynes in 2003 (ISBN 9781859-608807) – not to be confused with the New Mini Performance Manual which focuses on the BMW Mini.
Delights of a Downton
The 1967 Mini Cooper pictured here is rather special, as it’s a Downton-tuned edition bought as several boxes of bits in 2012. It’s owned by Paul Moran who comments: “A dealer was selling the Cooper as a project, but they didn’t know that it was a Downton-tuned car. Once I’d handed over my money I started to research the Mini’s history, initially via the archives at Gaydon. It transpired that the car had a unique build number which couldn’t be explained. But I did establish that the car was originally sold through a Herefordbased dealer.
“I contacted the records office for Hereford County Council and while they don’t routinely keep all records of cars sold 50 years ago, they did have a few and mine was one of them. Although it wasn’t immediately obvious, from the limited documentation available it turned out that the original owner was the engineering company Rubery Owen [Ro Style wheel fame-ed], so I contacted them.
“Rubery Owen has an archive but couldn’t tell me much about my car. However, I’ve got to know Sir David Owen very well along with his brother Jim and they’ve really enjoyed seeing the Mini now that it’s been restored. I’ve also joined the Owen Motoring Club (owenmotoringclub. co.uk) which was established in 1959, when the Owen Organisation ran the BRM racing team along with Rubery Owen; the latter is still going as an R&D facility. The Owen Motoring Club is a local motoring group that’s open to anyone and sometimes the Mini is displayed on the club’s stand at events.”
It took three years for Paul to return his Cooper to the road, with as much of the original car retained as possible. Says Paul: “The speedo had just 4000 miles on the clock but I don’t know if that’s original. When I got the engine rebuilt the engineers reckoned the car had covered hardly any miles – they also discovered that the camshaft was something they’d never seen, before so presumably it’s a Downton item which is very rare. You can still buy original Downton parts when they crop up and in period you could buy kits through motor factors, but most Minis weren’t tuned to any great degree. This one seems to have had a lot more spent on it though as it appears to have every mod going: a polished inlet manifold on a bespoke (unique to Downton) cylinder head, air filters, sports exhaust and twin 1 ½-inch SU carbs along with that unusual camshaft. The brakes, driveshafts and dampers were also upgraded to Cooper S items for better reliability”.
Paul reckons his Mini is about 65 per cent original, with most of the bodyshell and mechanicals retained. He had to source some new front seats though after the originals were lost. When Rubery Owen sold the car on it went to the South of France where it remained until it came back to the UK and Paul bought it. In France the car was laid up and turned into a kennel for the owner’s dogs…
Thanks to the volunteers at New Hall Mill, who turned up to open up the mill especially for us to take our photos. The mill holds regular open days and it’s located in Sutton Coldfield, near Birmingham. For more about the Grade 2-listed New Hall Mill and when you can explore it, log on to newhallmill.org.uk
Small Body - Big Rust
Minis rust horrendously badly, so you need to check everywhere; outer and inner panels, floorpans, bulkhead – leave no stone unturned. Inner and outer front wings are especially rot-prone, especially the metal around the headlamp and all the seams between the various panels. The rain gutters can rot through while the rear wings are just as likely to be as bad as the front ones. The rear valance could well be history by now and the same goes for the lower edge of the bootlid and the boot floor – which is frequently eaten away by leaking battery acid.
The sills (outer and inner) are often rotten, along with the wheelarches, door bottoms, floorpans and subframes; once the latter has started to corrode significantly, wholesale replacement is needed.
New BMH body shells are available from BMH but cost almost ten grand plus painting. On the other hand, it may prove cost effective in the long run with a restoration project although you will lose originality. Your final check should be the rot-prone A-posts, as effecting decent repairs is a real pig of a job. There are several panel joins and box sections to deal with, so lining everything up and gaining access is a real pain. So watch for endless bodges!
How to spot a counterfeit cooper
As prices have risen, so the temptation for the unscrupulous to turn ordinary Minis into fake Coopers has followed. Whether from a defunct logbook or upgrading an ordinary Mini into something much more desirable, the wide availability of detailed production reference material now means that it’s possible for someone to pull off a creditable fake. The problem is, finding the correct original parts, such as its vented steel rims (right) can be massively expensive.
- Join an enthusiasts’ club like the Mini Cooper Register so that you can tap into their decades of expertise.
- Is the car in question known to them? It helps if it is.
- Make a study of the features you would expect to see on the car in question. For example, a genuine Mini Cooper S engine will have removable tappet chest covers on the back of the block and an extra stud and bolt at either end of the cylinder head. A substitute 1300GT unit may look like the genuine, but the back of the block is solid with no tappet chest covers.
- Does it have a continuous ownership audit trail going back many years or has it just appeared from nowhere with little or no provenance?
- Most enthusiast restorers take ‘then and now’ photographs as they carry out their work. The absence of any such record should make you wary.
- A Heritage certificate should never be taken as evidence that the car it now attests to is the genuine article. Shady sellers can try to pass off a Cooper as a 1275cc Cooper S by means of an engine change and uprated disc brakes.
- Mini shells have an ‘FE’ number spotwelded on the inner wing adjacent to the radiator. The Mini Cooper Register can now date a car from the ‘FE’ number alone.
- Many components on a car, the trim and electrics in particular, including the windscreen wiper motor and distributor, have date marks on them. The glass too will have a date code. Although by no means an exact science, on a genuine car the various dates should mostly tie up to within a month or so. On a car assembled from a jumble of separately acquired parts, they won’t. But, if the price is right there’s little wrong with a ‘Cooperised’ Mini, if you know what you are getting that is!
What To Look For
Power Points
Ensure you’re getting a Cooper powerplant; substitutions are often made. There are key issues that can crop up with any A-Series, includes overheating and oil leaks. Also, check for worn piston rings and bores, betrayed by oil being burned, especially upon acceleration after the over-run, while a noisy top end suggests that the rocker gear or timing chain are worn.
If the unit runs unevenly, it could be a split head. Coopers featured a special head if the engine has been allowed to get too hot, such cracks by the valves could be evident; you need to check for misfiring as you rev the engine.
Transmission Troubles
The Cooper’s four-speed gearbox is under great pressure, as its lubricant is shared with the engine. Until 1968 there was no first-gear synchromesh; many cars have post-1968 ’boxes as they’re easier to use. If 22G1128 is stamped on the transmission casing, a four-synchro gearbox is fitted. The nylon gearchange bush is weak, but easily replaced. More importantly, the driveshaft rubber couplings frequently lunch themselves after getting soaked in leaking engine oil; replacements cost £150 a time.
Chassis Checkpoints
Pre-September ’64 cars featured conventional ‘dry’ suspension, with rubber cones and telescopic dampers. Subsequent Minis had Hydrolastic. Conversions from wet to dry are common, so if you want a completely original car make sure yours hasn’t been changed; it’s an involved job to convert back. The Mini’s rack-and-pinion steering is one of its best things; vagueness or stiffness means a new rack is needed. If play is in the steering wheel, it’s because the bushes at the top (and maybe the bottom) have worn; expect to pay £80 to have them both replaced.
Three Of A Kind

BMC 1100 & 1300
Think of the bigger brother as an overgrown Mini but family sized. The boy-racer 1300GT (pictured) is a hoot to drive, and while these are among the most valuable of the ADO16 variants, you can buy any of the others – such as the MG 1300 (which has virtually a Cooper S engine after 1968 and plush Vanden Plas, Wolseley and Riley variants – and have just as much fun. Much cheaper than a Mini but parts harder to find.
Rover Mini
Cooper was reborn for the 90s with a standard 1275cc engine (first carb, then EFi after ’96 coupled with taller gearing) with modern conveniences. Lots on options from Cooper (including Works S tuning kits) and wealth of special editions, some highly coveted. Much cheaper than originals with prices from £6000 but they rust just as badly and the EFi cars can have an assortment issues. Just as much fun as the early cars though.
Mini 1275GT
When the Cooper and S were dropped by BMC the 1275GT took over. For years these restyled cars were shunned by Mini fans, but now they’re becoming collectible – although values are still low. More of a Cooper replacement, rather than Cooper S, the 1275 single-carb engine is tuned to give 59bhp (later just 54bhp), it’s easy enough to pep things up a bit if you don’t crave originality.Verdict
The hype is all true. No matter what you’ve driven before, get behind the wheel of a hot Mini and you’ll get out at the other end spouting clichés about go karts. The Mini’s massive popularity and motorsport success aren’t mere flukes; its agility, affordability, economy and practicality conspire to make this one of the most fun and usable classics bar none. Then there’s the social scene. Buy a Cooper and there’s an array of clubs that’ll welcome you with open arms, whether you’re a fan of the concours scene or you want to use the car as intended.
Parts availability is superb, specialist support is unrivalled and prices are only going one way, even if genuine Coopers and Cooper Ss are hardly a bargain. On that note, be very careful before buying any car because prices vary wildly. Vendors know that these cars are in demand and they’re not afraid to be bold with their asking prices – many of which are hopelessly unrealistic.
Thanks are also due to Mini Cooper enthusiast John Parnell of the Mini Cooper Register (http://www.minicooper.org) along with Richard Williams of Richard Williams Classic Minis (http://www.rwclassicminis.co.uk).
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