THE ALVIS "SPEED TWENTY"
THE ALVIS “SPEED TWENTY “
SMOOTHNESS, PHENOMENAL ACCELERATION AND HIGH MAXIMUM SPEED CHARACTERIZE LATEST MODEL . . .
FROM the inception of the Alvis company in 1919, their name has always been associated with the production of sports cars, and their products soon gained for themselves an enviable reputation for performance and excellence of material and manufacture.
Many seasons of racing experience gave them valuable data for the building of their cars, one of their most notable victories being in the 200-miles race of 1924, when one of their famous 4-cylinder 14-litre models, forerunner of the 12-60 h.p. of to-day, averaged over 94 m.p.h. for the distance, a very wonderful performance for a car which was but little modified from the production machine.
They kept an active interest in records and racing for some years, and only recently decided to wait till our present races give up the handicap system as the means of deciding the winner of the chief trophy.
When they announced their latest model, the ” SpeedTwenty,” motorists immediately became enthusiastic, and the description of the chassis which appeared in MOTOR SPORT at that time showed how neatly, and with what strength, the new model had been fashioned. Now that we have had an opportunity of testing an example for ourselves we have been able to realise that appearances were not deceptive, and the performance and handling were fully up to expectations. This model owes a great deal in the power unit to the 3-carburettor Silver Eagle, but in the chassis layout itself, it is entirely new. Those who read our road test of the Silver Eagle in MaroR SPoRT of June, 1930, will remember that our verdict was roughly this—a fine car, but too high for the best results in cornering. Good cornering naturally depends on other things besides chassis height, and the Alvis Company were not to be rushed into producing a car which was low without
having the other important factors a so brought into line, and their policy has been fully justified in the “Speed-Twenty.”
Before describing our impressions of this car on the road, we will run through its main constructional features. The six cylinder monobloc engine has a detachable head, carrying the valves, these being operated by push rods. Separate water passages between head and block obviate the necessity of using the main gasket to seal the water joints.
The 4-bearing balanced crankshaft has oil fed through it to the main and big end bearings by a gear type pump driven from the shaft by spiral gears. The camshaft and auxiliary drives are taken from the rear end of the crankshaft through duplex roller chain with automatic adjustment. The valve rockers and push-rod ends are lubricated under pressure.
Mixtu e is supplied by 3 S.U. carburettors, and ignition by a B.T.H. polar inductor magneto and also by coil, the latter for starting and in the unlikely case of magneto trouble. The fuel is fed from the rear tank by an A.C. mechanical fuel pump. The 4-speed gearbox has a central change lever, and incorporates a silent third gear. On the road the smoothness and silence of the engine were particularly pleasant, and enabled the car to be driven equally effectively on top gear under all circumstances of traffic, or hard on the gears as the driver’s mood dictated. At first we did not feel that the acceleration was much out of the ordinary as it was so smooth and free from fuss and noise. It soon began to dawn on us, however, that other vehicles were overtaken with extraordinary facility, whatever gear was in use, and when we came to get the actual figures against the clock we found that they were really rather remarkable for a 24 litre unsupercharged car in which weight has no
where been skimped and strength has been the primary condition. The only thing which prevents these. figures being better still is the fact that the upward gear change is rather slow,—that is , unless brute force is used to engage the gears. This not being a good method of operation we did not employ it, and normally used, the gear is very pleasant and
easily managed, though the necessary wait is bound to produce gaps in the acceleration curve.
There was a very slight period at just over 2,000 r.p.m. in the engine we tried, but it was hardly noticeable, and at all other speeds up to 4,500 r.p.m. it was as smooth as could be wished. The driving position was comfortable, and the controls well arranged. The accelerator pedal, which is on the left of the brake, has an extension from the tip to the floor, and this makes it easily operated by the right heel when braking and changing down at the same time. This practice, which some racing drivers seem to imagine they have invented, but which is actually quite general on all sor s of vehicles where the pedals are suitably arranged, saves quite a lot of time and trouble in ordinary touring, especially in these days when we no longer drive on the hand brake. The Alvis brake ; are cable operated, the foot brake
adjustment being easily operated by the driver while travelling, and they have a slight, but well controlled servo action. When applied hard they are extremely powerful, but are s o progressive that locked wheels are rare, even on wet roads, and control is consequently excellent. From 40 m.p.h. the car can be stopped in 57ft. on wet, but not greasy,
tarmac, without locking any wheels, and on a dry surface this already excellent figure can be improved on slightly.
The wet weather behaviour of this car is very good indeed, and brings out to the full the excellence of the weight distribution and steering.
When cornering fast it is not only free from rolling,— the low build sees to that—but the layout is such that it clings to the intended path at quite unexpected speeds, and when centrifugal force does eventually produce a skid it is of the rear wheels only, and easily controlled. When we took over the car the suspension was too lively, as the Andre dampers were quite slack, but once these had been adjusted the springing was really good. The car held the road really well over all sorts of surface without being harsh, and a test carried out with a load of first one person and then no less than six, showed
that the suspension is thoroughly self adapting to variation in load.
With regard to the shock absorbers we have one small criticism to make. The rear pair of these excellent fitments was so situated that it was necessary to crawl under the car to adjust them, access from above being, as far as we could see, barred by the batteries and cross member.
Although this car is as quiet and tractable as any touring model advertised as a “top gear motor,” it is definitely fast. The maximum speed, as handed over to MOTOR SPORT, was 88 m.p.h. on the level, and would doubtless vary on different cars with different bodywork. The hood on the standard tourer disappears very neatly and gives the car a very finished appearance when down. It is not, however, by any means quick to erect
owing to the number of fasteners to undo and do up, and the hood itsel is not up to the very high standard set by the chassis as a whole. If a disappearing hood is to be used, there seems to be no reason why some adaption of the ” Zip ” fastener could not be used where it fits on to the body. It is a very fine achievement, turning out the standard tourer at £695, and it is really remarkable value, both in quality and performance. For those who wish for something a little more individual or luxurious there is a most attractive range of coachwork by Van den Plas on this chassis. These are handled by Charles Follett, Ltd., of 18, Berkeley Street, W.1., the Alvis distributors, to whom we are indebted for the loan of the car tested by