THE: 1933 LE MANS ASTON MARTIN
CARS produced at the Aston Martin works have always had a distinctive character of their own, and the Le Mans model embraces in a high degree the features of high mechanical efficiency, roadworthiness and ability to stand long periods of full throttle ; all this with a silence and refinement of handling which makes it an ideal dual-purpose car.
A visit to the factory at Feltham reveals the care with which the car is built, and the hand-work which goes into the assembly not only of the engine, but of such parts as the front axle, with its tubular ends polished inside, and the gear-box.
The engine and chassis follow the lines of development which have been evolved by racing. The four-cylinder engine has a single overhead camshaft driven by a half-speed chain at the front end, and provision is made to avoid disturbing the timing when the head is removed. Two valves per cylinder are fitted, operated by fingers. The fulcrums are eccentrically mounted, and by rotating them a fine adjustment of valve clearance can be made, and the rockers can be removed easily by slacking off the locking nuts. The combustion chambers slope steeply up towards the exhaust valves, allowing the inlet ports to be inclined and thus offering little obstruction to the incoming gases.
Forged elektron pistons are used, and duralumin connecting rods, so that the reciprocating weight is low. The Nitralloy crankshaft is carried in three bearings and is exceptionally stiff. Magneto, starter and water pump are spigot-mounted on the side of the crank-ease, while the dynamo is driven off the front end of the crankshaft. The two S.U. carburettors are fed by two Autopulse pumps, one of them drawing off the reserve supply of two gallons. The cylinder block is cooled on the tilermo-syphon system, while a water-pump is used to maintain circulation in the head. A two-gallon oil tank is carried between the front dumb-irons, and the oil is pumped into the engine through a pressure filter extending the entire length of the cylinder
block. A large scavenging pump returns the oil to the front tank.
The engine and gear-box unit is carried on four bearer arms mounted on silentbloc bushes. A single dry-plate clutch transmits the drive to the unit-mounted four-speed gear-box. The shafts are short and 11 inches in diameter, and the casing is ribbed and strengthened internally to resist distortion. All the gears have
straight teeth, but the care with which the gear box is assembled and run in before being fitted to the car results in a sturdy and silent running unit.
The transmission follows orthodox lines, with an open propellor shaft fitted with two universal joints, and a spiral-bevel back axle.
The chassis, which is upswept in front and passes under the rear axle, is rigidly braced by six cross-members. Flat underslung semi-elliptic springs are fitted, with shackles at the rear ends. The front axle is of I section between the springs but the portions between the springs and the stub axles, which have to resist the braking stresses, are of hollow tubular construction.
The brakes, always a notable feature of Aston Martin cars, are 14 inches in diameter, the ribbed aluminium drums being fitted with high-carbon steel liners to resist wear. They are actuated by enclosed cables, and the adjustment is effected by a wing-nut on each brake-arm.
First impressions, especially if they are favourable, are often worth recording. During our run in the Aston Martin, occupying first the passenger’s seat, we were impressed with the comfortable seating position, upholstery, and riding comfort, the pleasant sound of the exhaust, and the general effortlessness of travel. There is plenty of elbow and leg-room and the low-hung chassis and powerful brakes encourage the passenger to forget that he Is in a motor-car driven by someone else and to remain unperturbed by any manoeuvres the driver may care to attempt.
The driver sits in an erect position, the only safe posture for fast motoring, and can see the front wings without stretching. The steering wheel comes right into the lap, the short gear-lever, of the remotecontrol type lies under the left hand, and the hand-brake lever, with a racing rachet, is fitted almost horizontal on the right, and does not interfere with getting in and out of the car. Clutch and brake pedals are arranged in a comfortable position, but there is not much room to put one’s left foot when not using the clutch.
When the car was handed over to us, the 17 gallon tank was full, but with the Andre shock-absorbers properly adjusted the large load of fuel did not upset the handling of the car, and gives a cruising radius of well over 400 miles. The steering is light and positive, with plenty of caster action, and gives the driver complete mastery over his vehicle. The weight distribution was just right, and if ever a corner were taken too fast, the tail could be swung round to put the nose straight again, a thing which made fast driving on twisty roads very entertaining.
No alteration of the suspension was required on Brooklands or elsewhere, and the car rode the track steadily and in complete comfort. Timed over a half mile, with a slight favourable wind the car averaged 86.7 m.p.h., and later without its aid the speed was 81.8 m.p.h. For a fully equipped and comfortable motor-car these figures are very satisfactory. The braking distance from 40 m.p.h. was 601t., not as good a figure as we have previously had on Aston Martin cars. Actually on the road the brakes proved very reliable and could be applied with full force without any unpleasant consequences. Developed by competing in the Le Mans 24 Hour Race and other long-distance events, the outstanding impression one gets from driving the Aston Martin is one of stamina. It runs steadily for miles at 70 m.p.h., when the engine speed is about 4,000, a very different matter from the occasional reaching of this speed
which a less powerful car might manage, and the elaborate precautions for cooling water and oil ensure freedom from trouble under these conditions. On the other hand, should one wish to ” scrap ” other motor-cars, or to put up a fast average on winding roads, the gearbox makes it easy to do so. 45 m.p.h. and 65 m.p.h. can be reached on second and third gears at the safe revs. of 4,750, and in emergency one could go up to 5,000. All the gear-wheels have straight teeth, but are quiet running at normal speeds. They become more noticeable at full revs. With second gear one can get away from a curve in a satisfying way, and bottom is low enough for trails. The carburation was good throughout the
range and the engine went up to maximum revs, without a period in any part of the range. The headlamps, which are controlled from the centre of the steering wheel, give a powerful driving light, and in the dip-and-switch position the near-side one projects a beam equally suitable for spotting cyclists and driving in fog. A Trico suction wiper is fitted and by having a reserve vacuum tank, it continues to work even when the throttle was fully depressed. On the car we tried, Trico vacuum operated horns, working on the same system, were fitted. They gave a distinctive warning note and actually enhanced the appearance of the front of the car. Another interesting accessory
was the Donford car-lock, which affords absolute protection against theft.
The 2-4 seater body on the car we tested is a sensible compromise between the racing two-seater which has no luggage room and the four-seater which is apt to detract from the high performance expected from a 1+ litre sports car. The two front seats are adjustable and give plenty of leg room in the rear-most position. They are fitted with pneumatic upholstery and give good support for the back.
The rear portion of the body affords room for a number of suit-cases, the hood, which is permanently attached to its sticks, and a large tool-box extending right across the car. A cushion is not supplied as standard, but in emergency one or two passengers could sit in the back and would be under cover with the hood raised.
The appearance of the car is on a par with its performance. The lines are sleek without suggesting insufficient groundclearance or scanty passenger accommodation, while the domed cycle-type wings hint at the car’s racing career without sacrificing protection from mud-slinging.
Some cars give one the impression that they would be entertaining for an occasional afternoon’s “blind,” while others, though pleasant enough, do not arouse great enthusiasm. The Le Mans Aston Martin is a car which one would like to keep and use continually. There always is a market for a hand-made article of the highest quality, and the increased demand for this season’s cars may be guaged from the fact that the output of the factory has lately been doubled.
The maker’s address is Aston Martin Ltd., Feltham, Middlesex, and the Le Mans two-seater costs £595.