A.C. SPORTS TWO-SEATER
AN ATTRACTIVE LITTLE CAR CAPABLE OF OVER 80 M.P.H. AND EQUALLY SUITABLE FOR TRIALS AND FAST ROAD-WORK
Take a powerful and smooth-running 2-litre engine, instal it in a shortish chassis eminently suitable for fast cornering and narrow lanes, and crown it with an attractive and comfortable two-seater body. That is the prescription of the short-chassis A.C., and an exhilarating tonic it proved when we tried it in a weekend of hard driving. The engine is identical in design with that of the four-seater car, except that the compression ratio has been raised to 71 to 1 to give the utmost performance on standard fuel. The short-chassis, 8 ft. 10 in. instead of 9 ft. 7 in., has been produced at the request of trials enthusiasts, so what better test of the car than to take it down to Gloucestershire and try it up some of the London-Gloucester
pimples” ? In the hurry of getting away incidentally we forgot to secure the two wheels shod with Dunlop Competition tyres which we had waiting for us in the stores, and so had to tackle the gradients using only the far-from-new standard covers.
Setting off from Thames Ditton for the West, in a very few miles we had decided that here was a car which was a real joy to drive. To begin with the gear-change, always an important matter to the enthusiast, was beautifully easy, the snicking across the gate in one from second to third and almost as swiftly into top. Gaining a speed of anything between fifty and seventy miles an hour, the throttle could be eased back, allowing the car to swing effortlessly with no drop in speed and with only a gentle murmur from the exhaust, which is a pleasant change from the majority of small fast cars. Of course it is not so surprising when one that a 2-litre engine is installed beneath the bonnet, but the car gives that lightness of handling which one with cars half the size. With such a useful power-weight ratio, a top gear 4.2 can be fitted without making the feel over-geared, and at 60 m.p.h. revs, at approximately 3,000. The springing is firm, in keeping with the sporting character of the car. The telecontrol shock-absorbers proved worth, giving quite comfortable riding when fully slacked off for town work, while t mc vheelbase is sufficiently long
the gradient is reputed to be 1 in 4. Letting in the clutch at about 3,000 r.p.m., we got away without the slightest difficulty. The rocky outcrops and boulders at the top of Mill Lane are too damaging for any owner who respects his car, so we turned the wheels towards Stroud and the Golden Valley.
Bismore, the hill leading down from Eastcombe village to Ferris Court, was dry, and the car made light of its gradient, reputed 1 in 4 at its steepest part. We then shot off up Ferris Court itself, rounding the hair-pin with half the road to spare, finishing at the summit at full revs on bottom. Unfortunately there is a long wait between bottom and second gears, which can only be reduced by crashing through, but anyhow one rarely gets above 23 m.p.h. in this type of test. Following the roads at the top of the hill, we revisited Stancombe, down the precipitous hill which is so alarming in night trials. With well-worn tyres the wet surface of 1 in 5 might have been unpleasant, but the engine pulls strongly down to 2,000 r.p.m. and we contrived to avoid getting wheel-spin.
Back again nearer Stroud we tackled Quarhouse, where alternate mud and loose gravel meant gentle work with the throttle. The stone setts of Bussage were dry and harmless, so we went on to Station Lane. The boulder-strewn surface at the bottom of the hill was merely, annoying without providing any serious obstacle. On the higher section, under the trees, there was a good deal of slippery mud about, and only a quick change into second, which the engine pulled quite willingly, prevented a Night on the Mountain Side. Our scramblings ended with Iles Lane, which has now returned to its former rutted condition. Too much reliance on the slow-pulling qualities of the motor nearly caused a failure, but we just contrived to trickle up the 1 in 5. With competition tyres, or even with full throttle from the start, the car would obviously have taken the hill in its stride.
On these half-dozen typical trials hills, therefore, it will be seen that the A.C. performed with flying colours. The surface was in most cases reasonably dry, but on the other hand the car was fitted with touring tyres inflated to normal pressures, and the writer has no claims to skill as a trials driver. The steering is decisive, the brakes are excellent, and the car is small enough to be manceuvred comfortably on the narrowest lane or hill. ‘Me ground clearance is 71 in., and the only projections below the line of the chassis are the permanent jacks attached to the rear axle. These could easily be removed when serious work is in prospect. Without being in any way freakish, the two-seater A.C. seems the ideal trials car. Returning to London we were again impressed with the purposeful way the car swung along at speeds around the 70 m.p.h. mark, while its short wheelbase and general handiness made it a machine which can be driven for long distances with a minimum of fatigue. Following our usual plan the car was then tried on Brooklands. Here we came up against an unexpected fault, the engine showing unwillingness to ” rev ” above about 4,200 r.p.m., though its normal maximum is about 4,500. Whether this was due to unsuitable plugs or a weak coil—the symptoms inclined us to think it was the latter—was not discovered, but even with this handicap the timed speed over a flying half-mile worked out at 81.7 m.p.h., as against a level 80 m.p.h. achieved on the open four-seater previously tested. When everything is in order, an all-out speed of about 85 m.p.h. is to be anticipated. Except for a slight trace of roughness at about 2,500 r.p.m. the engine ran smoothly throughout the range. For smooth running the ignition had to be retarded slightly up to about 3,000 r.p.in., the advance and retard being manually controlled with the usual small lever on the steering-wheel boss. Running on Esso Ethyl there were no signs of pinking. The petrol consumption with continual fast. running and full use of the
gears worked out at better than 20 m.p.g., and as the tank holds 20 gallons, no petrol stops should be required on the longest trials run. At 4,500 r.p.m. the speed on the gears are respectively 23, 47 and 68 m.p.h. At 4,000 r.p.m. on top, the road speed is almost exactly 80 m.p.h. As has been said, a considerable pause has to be made to avoid a noise when passing from first to second gear, though this can be speeded up considerably at the expense of a little noise. An alternate gear-box with synchro-mesh on second, third and top is also available, and on this all changes
are practically instantaneous. Second on the ” clash ” box omits a high-pitched whine, which disappears at higher revs. The lever can be pulled in one movement across the gate from second to third, which is a silent-running gear, and the change into top is almost as quick. Top gear is “forward-right,” which feels rather unusual at first. The brakes we found excellent. The snatch one is inclined to associate with self-servo brakes, has been eliminated and on flooded concrete the car pulled up all square in /5 feet from 40 m.p.h. On a dry road from the same speed the stopping
distance worked out at 57 feet. The application was smooth, and a firm pedal pressure was needed to get the full braking effect. The driving position is a comfortable one, with the hands resting easily on the wheel, and the right elbow supported on the cut-away top of the door. The driving scat is well padded, and its rounded
back holds one steady when cornering fast. Another six inches on the back would be an advantage for the tall driver, as the top of the seat at present is liable to make contact with the shoulder-blades. The driver sits low in the car, and the scuttle is quite high, but the top of the near-side wings can be seen without stretching. The screen is shallow but effective, and can be folded down. The short stiff gear-lever comes naturally under the left hand, and the handbrake to the right, while there is plenty of room round the pedals for large-sized feet.
Effective sweeping mudguards are a feature of the body, and they are lined with wire-netting to prevent splashing and damage from flying stones. Behind the seats there is ample space for two large suit-cases, rugs and so forth. The tools and battery are carried in lockers under the bonnet. The hood drops down into the luggage space, and this is covered with a tonneau-cover, split down the middle and provided with a zippfastener, and long enough to be fastened to the scuttle when required, protecting one or both of the seats. Unlike the average car engine, in which a cast-iron cylinder block is used the
A.C. Six employs wet liners in an aluminium water jacket. A useful amount of weight is saved by this method of construction, and its success is shown by the fact that the design has been little altered during the past ten years. The liners fit into rubber gaskets in the jacket, and their upper ends are spigoted into the cylinderheads. The combustion chambers are hemispherical, with inclined valves, operated by means of rockets from a single overhead camshaft. The camshaft is chain-driven from the rear end of the engine, and the top sprocket can be disengaged without upsetting the timing. Coil ignition is used, with the distributor and the dynamo accessibly mounted and drivent6T a crossshaft at the rear of the engine. Three S.U. carburetters are fitted, and are supplied by an S.U. electric petrol pump.
The crank-case is cast in one with the water-jacket, and carries the crank-shaft, which is fully balanced, in four main bearings. A torsion damper is fitted.
A large oil-filler is provided in the valve cover on the top of the engine, and the sump holds two gallons. The cooling water is circulated by means of a pump, a fan is fitted, and a thermostat in the top water-pipe quickly brings the engine to its best working temperature.
The gear-box is mounted in unit with the engine, and a single dry-plate clutch is used. A self-changing gear-box can be fitted in place of the standard pattern at an additional cost of j,”35. The other transmission details follow normal practice, an open propeller shaft with twoneedle-bearing universal joints transmitting the power to the bevel-driven back-axle. The chassis is a fine piece of engineering, built from high-tensile Tormanc steel. The side-members are upswept over the front axle and run straight back beneath the rear one, the principal bracing being a box-section X-member running from the rear engine mountings to those for the front ends of the rear springs The
rear springs are tmderslung, with pivots at the front ends and shackles at the rear, and Telecontrol friction shock-absorbers are standard on the sports two-seater. brakes are of the Bendix pattern, with cased cable operations.
Like the chassis the bodies are built throughout at the Thames Ditton works, The best of materials are used, and they should give satisfactory service over long periods. For an individual handbuilt car the price of the A.C. seems distinctly reasonable, and as our test of this and other models in the range has shown, the performance is fully up to the promise of the sporting lines, and would undoubtedly maintain the high prestige of the make, as the long-chassis model has done, in events such as the Monte Carlo Rally, the Paris-Nice and the Alpine Trial.
The short two-seater seems perfectly adapted as a car for fast touring, for trials and rallies.
to avoid pitching on corrugated surfaces. With 200-lb. pressure on the “shockers ” the cornering reaches racing-car standards, and fine averages can be kept up even on twisty roads. The steering is pleasantly high-geared, light and accurate and the caster action, though small, holds the car perfectly steady at all speeds.
Fifty miles from London rain began to fall. Wet roads made no serious difference to the car’s road holding, and we continued at speed. Unlike so many small ears one’s range of vision through the wind-screen was not restricted with the hood up, but longer hood-sticks would have been an advantage in keeping the fabric off the driver’s head. With one side-curtain in position, we arrived warm and dry at our journey’s end. The next day’s Alp-hunting was begun on Bushcombe Hill. an old favourite in the” Gloucester “though now no longer used. The hand-brake, though short and handy, proved amply powerful to hold the car on the steepest part, where