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Not since fish met chips – or, if you’re of a North American disposition, since peanut butter met jelly – has there been a more happy union than that of Ford’s compact and powerful small-block V8 and the lithe, agile and pretty AC Ace.
Born of expediency and ambition, what was created in 1962 proved to be far greater than the sum of its parts – a machine that turned the world of production sports cars and endurance racing on its axis, giving rise to a legend that has endured for more than half a century.
But of all the variants to emerge from the alliance between the British Thames Ditton factory and Texan team boss Carroll Shelby, it’s the last of the line that provides the most intrigue: the AC 289 Sports.
Marriages of convenience rarely last, but that’s what the Cobra project became.
For AC owners William and Charles Hurlock, it was a way of infusing the outdated flagship with a new cachet, at the same time solving an engine problem that had shadowed the model throughout its production life; from aged AC to proprietary Bristol and Zephyr ‘sixes’, the performance potential of the older design always fell slightly short of that of the chassis.
For Ford, the Ace was a shortcut – a ready-made sports car that could take the firm to the top of the podium faster and more affordably than anything else.
And for Shelby, the driving force behind the project, it became a way of realising a lifelong dream.
The very first Cobra prototypes varied little from the Ace, save modifications to make the engine fit and reinforcements to the chassis to cope with the extra power of the 260cu in V8.
Not long after the first car arrived in the States from Surrey, the pioneer destined for the track touched down in Los Angeles, heading straight to Dean Moon’s shop in Santa Fe Springs, which then housed Shelby.
From its debut race at Riverside in October 1962, the Cobra proved its mettle.
And though wins didn’t come straight away, a series of impressive showings – usually curtailed by mechanical failure – demonstrated not only the car’s performance but, crucially, its ability to beat the new Corvette.
With track success came rapid development.
Inboard rear discs were quickly ditched, and by the time just 75 of the initial 100-car order had been fulfilled, the switch was made from 260 V8 to the uprated Hi-Po 289cu in small-block.
By chassis CSX2126, rack-and-pinion steering had replaced the Ace’s vague steering box for the MkII, while by CSX2160 side vents in the front wings had been added along with lightly flared wheelarches to accommodate wider 6in wheels.
The biggest change to affect the Cobra line-up came in 1965 with the arrival of the MkIII, which featured a completely redesigned chassis and a big-block 427cu in V8.
The idea had been trialled as early as 1963, when Ken Miles shoehorned Ford’s 7-litre engine into the chassis of a standard Cobra, fresh off the boat from Blighty.
Fitted with uprated brakes and dampers and sporting peg-drive alloy wheels – and by then a 390cu in V8 – the car was put to work at Sebring in 1964. It was an abomination, an unruly pig of a thing that could barely stay on track.
Miles stuck it into a tree in practice, and after it was patched up the race wasn’t much better.
Fuel starvation and leaking hydraulics marred a frustrating debut, and the car finally gave up by expelling a conrod on to the track.
The experiment showed up a chassis that had its roots in the early ’50s, and though Shelby wasn’t exactly fired up by the prospect of the big-banger, he realised that a stronger, more advanced chassis was a necessity.
Ford was more enthusiastic, keen to extend the Cobra’s competition life with the 289 by then being comprehensively outgunned.
The new frame was a collaborative effort, with Ford’s computer – plus a little help from suspension guru Klaus Arning – contributing the geometry to AC, where in-house engineer Alan Turner turned the ambitious printouts into a more grounded reality.
The result bore a familial resemblance to the outgoing chassis, in that it still featured two longitudinal tubes, though these were beefed up to 4in diameter, as well as being set further apart.
Uprights rose at each corner – single at the front and double at the rear – braced at either end.
At the front, in place of the old transverse leaf springs, the suspension comprised unequal-length wishbones with 4½in coil springs allied to Armstrong telescopic dampers, while the rear incorporated trailing arms and springs with two fewer coils.
Despite a monumental effort to meet homologation rules for the 1965 season, the requisite number wasn’t hit and just 56 of the intended 100 cars were built – some detuned and sold to the public as fire-breathing road cars.
The ‘production’ 427 didn’t fare much better in showrooms, however, and by 1967 Shelby had wound down imports.
There the story might have ended but for AC, which decided to continue production for a further two years.
Not only would the car be badged as an AC – cocking a snook at Shelby, who removed the crests from the earlier cars as soon as they got Stateside – but it would combine the best componentry from across the range, mating the big-block’s coil-sprung chassis with the 289cu in Hi-Po engine only offered up to that point in the earlier leaf-sprung cars.
Chassis COB6116 is one of these special machines, just 27 of which left the Thames Ditton works between 1967 and late ’69. (Cars for export wore ‘CSX’ chassis numbers, while UK cars featured ‘COB’ numbers.)
Originally finished in Pacific Green over black, it rolled off the line at the end of January ’67 and headed to Hersham and Walton Motors in Surrey, from where it was purchased by David Skailes – with a Marcos 1800 taken in part-exchange – before being delivered by none other than HWM co-founder George Abecassis.
Though Skailes was no stranger to the track, the 289 Sports was used predominantly as a road car – testament to the usability of the package – before being sold on.
The lure of great power is always a draw, and in the ’70s the car found its way to the workshops of Brian Angliss, who was commissioned to transform the 289 into the firebreathing big-banger for which the chassis was originally intended.
A side-oiler 427 was fitted – not the softer, cheaper 428 that found its way into some factory cars – while the delicate bodywork was modified to match the engine, with wider, more aggressive arches.
Things changed again when the car was later sold to Japan, and the big-block V8 was replaced by a 302 and the body was refinished in metallic blue.
By 2015 the AC had found a home with its current owner, whose passion for originality resulted in a comprehensive overhaul of the mechanical components that included a return to the original-type Hi-Po 289.
The slightly more muscular bodywork that was formed around the original bonnet, bootlid and doors was retained, as was the colour, but in every important respect COB6116 is now back as the factory intended. And how it sounded.
Check the isolator, let the fuel pump prime the carb, turn the key and the twin pipes report with the same angry burble that was first heard as the car left its Surrey birthplace in 1967.
There’s a power trade-off associated with the return to the correctly dated engine, though the figures are still impressive in a car that weighs so little: 271bhp at 6000rpm, and 312lb ft of torque at just over half that.
The Hi-Po 289 has plenty of muscle, but the AC isn’t the lazy animal you might imagine: it’s a great bear of a thing that comes to life when the throttle pedal is stabbed.
This is no lolloping boulevardier, but a shivering mass of muscle and sinew whose vocal range spans from rolling thunder to a screaming song.
Of course, it’s possible to stick the AC in top and rumble along at anything over 25mph, but you’ll rarely find yourself doing it.
The ratios are so well judged and the acceleration so thrilling that the seemingly unburstable V8 rarely drops below 3500rpm on cross-country drives.
Keep the revs up and the power delivery is instant; the casual jogger becomes the Olympic hopeful, and you’ll swear you catch glimpses of Miles, Dan Gurney or Bob Bondurant in the rear-view mirror, if only for a moment.
Push the AC to its limits and you’ll quickly be reminded that you are not, in fact, an endurance-racing legend.
While the talented and brave reported in period tests the ability to ‘use more throttle to keep the tail in check’, a hair-raising twitch is enough to make lesser mortals ease off.
Early Cobra brochures described such comforts as ‘a full instrument panel’, and as you contort your left leg past the enormous transmission tunnel and on to the clutch pedal for another change, the irony isn’t lost.
In this car you work around the machine in many ways, and in harmony in others: the short-throw, direct change of the Borg-Warner T-10 ’box is a delight and the steering, of the revised rack-and-pinion type, is perfectly weighted when matched with the lighter small-block motor.
The leaf-sprung Cobra was always an effective yet slightly crude device in comparison with European sports cars; like using a hammer to drive a screw.
This is a more considered machine, as bouncy and choppy as befits a roadster born in the mid-’60s, but at the same time boasting a compliance that blunts the worst characteristics of the earlier Cobra while accentuating the best.
It lacks the outright power of the fearsome 427, but the 289 Sports is lighter, better balanced and more wieldy; you don’t need bulging forearms to pull it into line or haul it back from the brink.
Period reports cast some doubt on whether it could be used as a 20,000-miles-a-year everyday car, but simply asking the question highlights the sheer usability of this last-of-the-line small-block wonder.
The more time you spend with it, the better it gets.
Images: Will Williams
Thanks to The Classic Motor Hub
AC 289 Sports
- Sold/number built 1967-’69/27
- Construction twin-tube cross-braced steel chassis, aluminium body
- Engine all-iron, ohv 4727cc V8 with four-barrel carburettor
- Max power 271bhp @ 6000rpm
- Max torque 312lb ft @ 3400rpm
- Transmission four-speed manual with Salisbury limited-slip differential, RWD
- Suspension independent, by double wishbones, coil springs, telescopic dampers f/r; rear trailing arms
- Steering rack and pinion
- Brakes discs
- Length 13ft 3¾in (4057mm)
- Width 5ft 5in (1651mm)
- Height 4ft ¾in (1238mm)
- Wheelbase 7ft 6in (2286mm)
- Weight 2094Ib (950kg)
- 0-60mph 5.6 secs
- Top speed 135mph
- Mpg 17
- Price new £2951
- Price now £4-500,000+*
*Prices correct at date of original publication
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