100’M.P.H. PERF.ORMANCE ALLIED WITH REMARKABLE ROAD-HOLDING AND STEER.ING

THE TWELVE CYLINDER ATALANTA SALOON

THE twelve-cylinder Atalanta is such an extremely good car that MOTOR SPORT has great pleasure in presenting this test, the first to be published in any paper, to its readers.

The performance is terrific, as might only be expected with the big Viz American engine in a relatively small chassis, and this is backed by superlative road-holding and cornering. The price, too, is really very reasonable.

The Atalanta is the only British production car which has independent suspension for all four wheels. This is an excellent feature in itself, and despite the adoption by the Grand Prix cars of De Dion-type rear axles, instead of independent rear springing, it is an arrangement growing in popularity on the Continent, and one which •cannot fail to make its mark in this country also.

However, to secure good road-holding one has not merely to lit all-independent suspension and straightway achieve one’s object, no matter what the system is like. There is far more to it than that, and the very difficulty of getting good results is one of the reasons why British manufacturers have fought shy of the additional complications involved by independent rear suspension. The Atalanta system is quite unique, employing in the front vertical coil springs, working in compression and mounted on a powerfully braced and triangulated structure, while at the rear the coil springs are mounted horizontally, alongside the frame members. Specially made double-piston hydraulic shock

absorbers are now fitted. The links *which support the stub axles are made of RR53 light alloy, and thus the unsprung -weight is very low.

Moreover, the wheels are mounted in such a manner that they have a parallel action, and cannot lean over, while the track does not vary on a bumpy surface. On many systems the track does vary, and although the effect of this upon tyre wear has been exaggerated by some Opinions, it is nevertheless an advantage to have wheels which move only in a vertical plane.

Put into practice, this system works in an enviable manner. One of the tests by which one may be regaled on a demonstration by the works drivers at Staines is to get up to 90 m.p.h., put the nearside wheels on the grass verge, and remove one’s hands from the steering wheel ! It must be admitted that the writer did not himself on the present occasion attempt this feat, because he was desirous Of returning the car to the manufacturers in one piece, but he has been in the car when it was done. The Atalanta responded easily to less sensational tests of the steering. On one occasion it was necessary to get from one point to another in the shortest possible time, but the shortest possible distance, viz., a straight line, was far from being available. On the contrary, the road was full of twists and turns, but the Atalanta went round bends at 80 m.p.h. as though it were on rails. When

this particular stretch had been completed, the passenger, who, it is believed, had never previously travelled at much above 70 m.p.h., remarked casually, “Well, I wouldn’t mind betting that you have never been along that piece of road

faster before.” This was undoubtedly the case.

One of the advantages of a car with good steering capable of 100 m.p.h.—for the Atalanta, as will be told later, did achieve the magic three-figure niark—is that if one approaches almost any corner at the right speed, one has still plenty of power left to drive the car round. Indeed, at 85 to 90 m.p.h. there is still quite a kick coming when one utilises the remaining throttle opening. It appears difficult to approach a corner at the wrong, that is to say, an excessive speed, with the Atalanta steering because if one has any judgment of speed at all, one nearly always finds that one has been reckoning by less exacting standards, and that one has under

estimated. So the acceleration comes into play, which is just as it should be for really enjoyable motoring.

The acceleration is quite something to write home about, assuming that the recipient of the letter is not easily shocked. In its native surroundings, that is to say, in the big eight chassis, the twelvecylinder engine enables one to step off the mark to some purpose, and with the smaller Atalanta one can really get going. The gearbox has synchromesh on second and top gears, and the change is sure and reasonably quick, without being instantaneous. It is curious, with the tremendous power available, that it does not seem possible to make the tyres squeal through wheelspin as one gets away from a standstill on a dry road. This may be due to some matter of torque at low speeds, which is quite different from power, but in any case is no discredit to the car, as wheelspin merely wastes time. The action of the clutch is light and sweet, and very pleasant for ordinary

work. However, whatever the effect of all these factors, there did seem a slight hesitation in the first fraction of a second when making a racing start for the purpose of acceleration figures from a standstill. But these figures can speak for themselves :—

Since Brooklands Track was still not fully available, these figures were done on a level piece of road, and represent a mean of several rums both with and against

the wind. It is interesting to note that the best figures from 0-60 m.p.h. was 12* secs., while the figures to 80 and 90 m.p.h. were particularly creditable. The gear ratios are 10.15 to 1 bottom, 5.77 to 1 second, and 3.6 to 1 top. On bottom gear a speed of about 30 m.p.h.. was found to be possible without overrevving, and on second gear 70 to 75

m.p.h.. The manufacturers had stated that the top speed of the car was likely to be about 95 m.p.h. This is no overestimation, for it proved in fact to be the give and take speed which the car would reach in any conditions.

But if anything this estimate of the maximum speed is pessimistic, for on one occasion during the test, a long, perfectly flat stretch of road allowed the Atalanta to get up to a speed of 101 m.p.h., with a slight wind behind. The speedometer was checked carefully, and found to be a trifle slow, an excellent feature, enabling one to be quite certain that ally speeds reached are genuine. Nothing is more irritating to the real motorist than to find that speeds shown by the instrument do not bear comparison with stop-watch times. The brakes are hydraulic, with Lockheed double-barrelled master cylinder, as in racing practice, to prevent any possibility of both sets going out of action through some such unlikely occurrence as a punctured supply-pipe. With huge

16 in. drums, they proved smooth and powerful. The hand-brake was located in a convenient position between the front seats, with a racing-type ratchet.

This particular car was the first of the type to be built, and has led the usual rough-and-tumble life of a works demonstration machine. There were, for instance, sundry squeaks and rattles in the bodywork, which naturally would not be present on production types. Through expeiience gained, it has been possible to eliminate other points of criticism. The chief and almost the only criticism which the writer had on returning the car was the fact that excessive heat was developed in the front compartment (though the water temperature, in spite of much fast driving, never rose above 800). He was at once led to a production car in course of construction, where it was pointed out that, to meet this very criticism, a double-sheeted aluminium

bulkhead had been adopted between the engine and the driving compartment. There is an air space between the aluminium sheets, with a scoop projecting through the scuttle, which causes a continual flow of cool air, and should entirely obviate the trouble. The writer also said that it was somewhat confusing to have to grope about under the dash to find the dipping switch, and this was met by the statement that on the production cars the dipping Switch could either be on the steering column, or foot-operated, exactly as a customer wished. In all such small points, a customer’s particular requirements are

met so far as possible. The lights, it may be mentioned, were extremely good, a.s witness the fact that when 101 m.p.h. was achieved, it was in the dark. The body was of a very pleasing shape, even as it was. It had two long doors, and a feature was the absence of any pillar between the front and rear windows, the sheets of glass interlocking in a cunning manner. The wide expanse of unobstructed window thus gave ex

cellent visibility on either side. Visibility all round was above the average, as with_ a low radiator mounting, the driver could quite easily see not only both side-lamps but the whole width of both wings as well. A good view out of the rear window—sometimes an advantage on a fast run—was also possible.

With the exception of the ignition system, 12-volt electrical equipment is used. The ignition system has two special 6-volt coils, one for each bank of cylinders, and each has its own fuse in case the coils. are inadvertently left switched on. Since the ignition is 6-volt, the petrol gauge has.

a separate switch. Petrol consumption with such a large and powerful engine is really extraordinary, being round about 20 m.p.g. at all ordinary cruising speeds of between 60 and 80 m.p.h. This can only be due to the efficiency of the induction system. A central manifold between the banks feeds all

twelve cyclinders, with one large downdraught carburetter. A mechanical fuel pump is fitted, and there is a big air-cleaner.

The twelve-cylinder side-valve engine, arranged in V-formation, has a bore of 69.85 min. and a stroke of 95.25 mm., giving 4,379 c.c. The cylinder heads are of aluminium alloy, while above the engine projects an easily accessible oilfiller. A float level indicator is provided for the sump, and there is an external oil purifier which needs attention Only every 20,000 miles.

Instruments include thermometer, fuel gauge, speedometer with clock, and a separater, and there is a lockable cubby hole in the dash. Twin Mellotone wind. horns are fitted. The wheelbase is 10 ft., and the track 4ft. 5 in. in front, and 41t. 6 in. at the

rear. The approximate weight of the saloon model is 26 cwt., and at a price of 4740, this safe and comfortable 100 m.p.h. car represents remarkable value. The address of the manufacturers i* Atalanta Motors, Ltd., London Road, Staines.