AC Ace

Auto Carriers Ltd

AC started out right at the very dawn of the automobile as Auto Carriers Ltd, producing a range of singularly odd commercial vehicles. After a financial reform they began, as AC, what was to be a long and patchy car production career, turning out one of the nicest voiturettes of the halcyon pre-1914 years - the Sociable three-wheeler. The Sociable's companion, a 1096 cc four-cylinder with a full complement of wheels, won a reputation as the best looking light car of its time. A 65 by 100 mm overhead camshaft wet-sleeve alloy six hit the market in 1922 and remained for decades to come.

In 1921 J. A. Joyce became the first person to clock 100 miles per hour, behind the wheel of an experimental 1.5-litre AC. And even before 1920 AC Cars were fitted with disc brakes. But innovation was not enough to guarantee the success of an automotive venture, and by the 1950s AC was in trouble. It seemed the public were not great fans of the distinctly odd long-wheelbase, beam axle saloons AC were manufacturing. The firm's directors began to look about them for the kind of design people did want.

John Tojeiro

The answer they were looking for came from a young British engineer-turned-racing-man John Tojeiro, and more particularly his creation - a Bristol-engined sports car called after its designer. The Tojeiro had for a whole season monopolised the pages of Britain's sporting weeklies, much as a certain Colin Chapman's creations were to do several years later, by romping home at the head of formidable fields in short-circuit races all across, the country.

The secret of the Tojeiro's success was an ingenious composite frame made up from paired main fore and aft ladder tubes, amply cross-braced, a network of small diameter stiffening body-support tubes, and a semi-stressed alloy skin. Suspension was all-independent. AC engaged Tojeiro to help them develop the Ace. To do it, he simply adapted his established ideas to the firm's limited production techniques. The Ace was suspended independently by a single transverse leaf spring at each end and a single tubular lower wishbone for every wheel.

Built-up sheet metal towers supported the springs and distributed stresses through the frame's, backbone tubes and to the small largely straight tubes of the overhead network. Engine placement was well back in the interests of weight distribution (helping to place some percent on the back wheels) and a low centre of gravity. Space around the compact power unit was more than adequate for most maintenance jobs. The battery, placed low in the engine bay, was a little hard to reach.

The Ace's shapely lines were sensational. The curves in every plane were generous, and cleverly matched, partly for reasons of aesthetics, partly for strength, and partly for lowered wind resistance. Overall styling was well integrated - a point that did not apply to many other British designs from the era. The shapely sides wrapped well under; the nose was gracefully contoured underneath as well as everywhere else. Lights and grille were designed-in as part of the car, not added as afterthoughts. That made it almost impossible to customise an Ace – but then, why would you want to?

A Brilliant Piece of Functional Design

Admittedly protection from minor bumps gots little attention. In a car to which even small panel repairs could be expensive, full-width bumpers were essential. Although the Ace's designers went out of their way to make an artistic success of its simple, almost Italian contours, they didn’t forget the practical things,. The Ace had a rare sports car luxury, a really useful boot. Spare wheel, hood, screens and tools all screwed and clipped into place in there with plenty of space left over for luggage. All of which was just as well, since there was little surplus room in the cockpit.

Indeed the Ace-Bristol's control space was a brilliant piece of functional design. There was adequate room there for driver and passenger, but no more. Meanwhile the cockpit was far less a weak point in the frame-skin structure than most. Its lip cut well into what would otherwise have been square corners at the edges of the scuttle and behind the seats, so that the opening was as small as possible and when the doors were shut stresses were distributed unusually well through frame and body. For the same reason, the door openings were made as small as they could be without making it hard to get in or out.

Detail finish everywhere was functional. When a piece of metal was exposed, AC made sure it didn't offend anybody. Carpeting, lining and upholstering was kept to strict limits, but where it occurred, it was well done. The car did not have a single piece of decorative trim. They did not put in, nor keep, anything that could reasonably be thrown away. Yet nothing was skimped, nothing botched. Door locks, hinges, weather sealing, boot, lining, floor insulation – it was all done properly, with a strict eye to the important things. The soft top, too, was really well designed. It would perhaps have looked better if it were not made quite so high at the back, but in every other way it was one of the best detachable hood then available. Uniquely, it didn't flap even at nearly 115 mph, and this combined with brilliantly simple opening side-screens which uniquely made the Ace a sports car that was really pleasant to use in the wet.

Behind the Wheel

The Ace-Bristol driver sat quite high, which is why the windscreen had to be so big. Sitting there at the wheel, you got a feeling of mastery over the car much like the sensation you got in the old sit-up-and-take-notice square riggers of old. Visibility over the long, lean bonnet was good. You could see the road quite close through the troughs between wings, and nose. The small, plain, rather unattractive wheel was adjustable on a splined column. Even pushed right forward, with the seat butting up against the bulkhead at the back, it didn't give quite enough reach - but the result was far from unsatisfactory. After a little time at the controls you were far too busy enjoying yourself to worry anyway.

The seats themselves were superb. The part where your behind went was troughed deep between two padded side supports, so you sat wedged tight for maximum control in turns. The firmly padded cushion reared up in front to hold your thighs. The backrest was wide enough to locate your shoulders properly. The pedals, conveniently hinged on their stalks and stamped as in days of yore with the AC trademark, were surprisingly badly placed. They all had a lot of travel, most of it unnecessary. Besides being annoying, the arrangement meant that legroom in the cockpit, which would have been only just big enough had the pedal arrangement been perfect, was instead limited. It was a tight fit to get your left foot down on to the dipswitch between the clutch, pedal and the bulky transmission housing. The accelerator was better placed, but it too moved through far too wide an arc.

Gearstick placement was good. The lever was long, but it didn't make for abnormally long movements between cogs. The shift pattern was well defined. Reverse was safe from accidental engagement. Minor controls were almost ideally laid out. Big, precise, white-on-black speedometer and tachometer dials, calibrated in fifths, lay on a plain recessed vinyl-covered alloy dash panel at either side of the steering column. Four minor dials were set in a T-shape above and beside the tacho: fuel gauge, oil pressure gauge, water thermometer across the top and an ammeter under the oil pressure with the old-fashioned (but highly efficient) ignition-lighting switch in a matching bezel below.

A microscopic clock face and trip and total mileage recorder were built into the tacho. The starter was a simple button within finger's reach of the ignition keyhole. Other controls in what was essentially very much a driver's car included ignition advance-retard and instrument lighting rheostat. The AC's dashboard had the studied, functional look almost like that of an aircraft control panel. On the passenger side of the dash there was a huge glovebox with a thinly padded lid.

The Brilliant Bristol Six

Early Ace-Bristols had AlFin drum brakes all around. The factory later substituted discs for the front wheels. The rugged, high-camshaft, crossed-pushrod Bristol six-cylinder was based on the celebrated 80 bhp pre-war BMW-325 , this very engine being built in several variations by a special division of the Bristol Aeroplane Company. From the factory and stock, the Bristol engine was good for around 125 bhp, but this could easily be increased to 140 or more. Enthusiasts that wanted even better performance could shave the head to give an extra unit and a half of compression (making it 9.5, instead of 8). Other mods performed by some owners was the fitment of bigger inlet and exhaust valves, matching and polishing, and streamlining the butterflies of the three standard Solexes.

First gear was good for around 40 mph. Wheelspin, thanks in part to the independent rear-end layout and brilliant Michelin tyres, was almost non-existant. A puff of rubber dust and a brief shriek from both back tyres was all you got as the Ace thumped back on its single tailspring and sprung lustily forward. A very crisp backward movement of the long, leather-shrouded gearstick brought up second and, almost as quickly, a healthy 60 mph plus. The AC's Bristol-built gearbox was one of the sweetest then going. Lever movements were admittedly long, but inside was one of the world's better synchromesh systems.

On the Road

It was on the road that the Ace really excelled. The handling was brilliant. The Ace's specification made it a natural for something special in the way of road adhesion. In practice it wass more than something special. It was a delight. It was one of the rare cars that built confidence. The Ace was at its best in the more trustworthy type of medium bend. There you could throw it into third, thrust the nose firmly into line and floor it. All four wheels would cling tight. Push the boundaries and you could usually persuade (thanks to the Solex's) the tail to slip gently towards the outside verge as centrifugal force build-up would overcome the adhesion ability of the tyres. When that happened it was no big deal, because the AC did nothing crudely, although you did have to act fast. A quick but purposeful snap of correction, confidently applied, would bring about a kind of controlled high-speed tailslide most driving enthusiasts only got to dream about.

The steering was not among the Ace-Bristol's strong points. It was heavy, rather slow and a little vague when the wheels were pointed straight ahead. Not that it was bad steering. Just a little too heavy then, and would be considered a dinousaur now by papmered drivers used to power everything. When you got behind the wheel of the Ace, and it was a big wheel, you had to put plenty of swing into your normal driving. A brief encounter does not quality us here at Unique Cars and Parts as being any kind of authority, and we would presume that owners would quickly adapt to the way the steering felt. But while we were no fans of the steering, the brakes on the other hand were bloody brilliant. The factory Lockheed-setup worked as well as any disc-front/drum-rear layout and was the equal of systems around today.