THE SPEED TWENTY ALVIS

Author

admin

Browse pages
Current page

1

Current page

2

Current page

3

Current page

4

Current page

5

Current page

6

Current page

7

Current page

8

Current page

9

Current page

10

Current page

11

Current page

12

Current page

13

Current page

14

Current page

15

Current page

16

Current page

17

Current page

18

Current page

19

Current page

20

Current page

21

Current page

22

Current page

23

Current page

24

Current page

25

Current page

26

Current page

27

Current page

28

Current page

29

Current page

30

Current page

31

Current page

32

Current page

33

Current page

34

Current page

35

Current page

36

Current page

37

Current page

38

Current page

39

Current page

40

Current page

41

Current page

42

Current page

43

Current page

44

Current page

45

Current page

46

Current page

47

Current page

48

THE SPEED TWENTY ALVIS

A SPORTS CAR OF QUALITY AND ADVANCED DESIGN, FURTHER IMPROVED FOR 1935.

THE name of Alvis has for many years been synonymous with sports cars of the highest quality and thea Speed Twenty since its introduction has had an enviable reputation for high performance and long-wearing qualities. Independent springing and an all-synchromesh gearbox w:ere two outstanding innovations brought in on last year’s cars, while on the model under review the designer has effected further advances in suspension, chassis design and quiet running which maintains its position as one of the leading British sports cars.

To the enthusiastic owner appearance comes close after performance, and the double-dropped frame allows both the makers and the specialised coachbuilders to construct coachwork which satisfies One’s conception of speedy lines without being in any way unpractical. This was the impression we had gained through seeing the new models on the road, and the road test we carried out showed that the car’s performance was as outstanding as its lines suggested. Altogether a well-balanced car which one remembers with real satisfaction.

We took over the Alvis from the West End showrooms of Messrs. Charles Follett, and in the pouring rain were not unpleased that the vehicle we had been lent was a large and comfortable saloon. The long bonnet and the ample wings might have proved awkward in traffic on a car with less visibility, but the Alvis has an upright driving .position and a wide and deep wind-screen, almost all of which is swept by the twin wiper blades. The driver feels quite in command of the situation as soon as he settles into the luxurious driving seat. A short run in busy streets showed that the engine is quiet and flexible, the suspension supple without sway, and in short the Speed Twenty has town-carriage attributes which are particularly welcome when the car is to be used continually in traffic-ridden parts of the country. Gaining the comparatively open bye-pass

Brief Specification.

Engine : 6 cylinders. Bore 73 mm. Stroke 110 mm. capacity 2762 cc. R.A.C. Rating 19.82 h.p. P-21.41 rod operated overhead valves. Dual ignition, magneto or coil. Three S. U. carburettors.

Gear-box : Font’ speeds and reverse. All forward ratios constant-mesh, and _fitted with synchromesh mechanism. Ratios 4.53, :6.53, 9.4 and 14.33 to 1. Central change.

Suspension : Independently sprung front wheels, with ‘transverse cantilever. spring. Semi-elliptic at rear.

Dimensions : Wheelbase 10ft. 4in. Track 4 ft. 8in.

Weight with two-door saloon body 32cwts.

Price £8.95.

roads leading away from the Metropolis, we were next impressed with the way in which the .car reached 55-60 m.p.h. where the slightest opportunity offered, with an effortless feeling which suggested ” 40 ” at the most.

On reaching Brooklands we found that the Railway Straight and the Bytleet Banking had still resisted the efforts of the repairers and some acceleration tests were carried out. Gaining the first-named at 60 m.p.h. over a narrow strip of concrete, the car accelerated in a striking fashion to 75 m.p.h. and beyond, and achieved a flying half-mile at 83 m.p.h. on the stretch of track between the Aerodrome and the Fork. Subsequent tests on the road showed that this was approximately the maximum speed, a, creditable one for a substantially built saloon, and further more, one which Can be attained in practise on English roads.

At 4,500 r.p.m. the maximum speeds on second and third gears were found to be respectively 40 and 58 m.p.h. An interesting point is that the exhaust note, which we considered rather prominent on former Speed Twenty models, is now pleasantly subdued up to 3,800 r.p.m., where it is joined by a certain amount of power roar, but not sufficient to be objectionable even in a saloon car. On top gear at these revs the road speed is approximately 75 m.p.h. and the sound is carried away by the wind. The engine is smooth throughout its speed range, and the carbutetion free from flat spots.

Rich mixture for starting from cold is supplied by an auxiliary carburettor controlled from the dash-board, and the engine always started easily in spite of the cold weather which prevailed during the time of our test. It was found advisable, under these conditions to disconnect the fan belt and also to blank off part of the radiator, so that one can rely on having a good reserve Of cooling capacity for summer work abroad. Independent front wheel springing is still such a rarity in this country that a

car so fitted commands special interest, and the system fitted to the Alvis fully justifies the claims of the designer. The spring itself is more flexible than that used on the 1934 models, and is damped by adjustable telecontrol shock-absorbers. These may be slacked right off for town use, with consequent easy riding, and only a slight pressure was called for even when negotiating the bumpy surface of the Track. However, adjusted, the suspension is unusually good, and apart from the cushioning effect, no shock is transmitted to the steering wheel even when mounting a curb, dropping into a pot-hole or negotiating the rough section of concrete at the Brooklands Fork.

Another feature of the Alvis is the constant-mesh gear box, which is fitted with synchro-mesh mechanism on all gears. The synchronising mechanism is a particularly powerful one, making it possible to effect a straight-through change on any gear. Consequently the change is heavier than it would be on the orthodox ” clash-type ” box, but one can change up almost as rapidly as with the self-changing box, surging forward with each movement. Useful time is also gained when changing up on a hill, while in emergency a change-down at an unexpected obstacle can be made while still keeping down the brake pedal, then accelerating at leisure. Double-clutching may still be carried out, using the synchrocones to speed up the change, and no unseemly noises can be made whatever one does.

Winding cross-country roads are not the kindest places to test a large car, so we were pleasantly surprised by the ” Alvivacity ” as the makers term it, of the Speed Twenty. With the shock-absorbers firm but by no means uncomfortable, one could safely forget that the car under test was a substantially built saloon and take it round corners with foot hard down. The wheels remained, as it were, glued to the road at all reasonable speeds, and with really fierce treatment the tail slid round gently and perfectly under control. On short pieces of straight road the speedometer swung round almost at once to 55-60 m.p.h., so much so that we found ourselves at fault on several .occasions through going into corners we knew well at quite unaccustomed speeds, and were glad to keep the brakes on and to push the gear-lever across in the way already described. The brakes themselves were powerful, light in action and progressive, and could be applied at full strength without causing the car to swerve ; from 40 m.p.h. they pulled the car up in 60 feet.

On reaching more open roads the speed of the car went up almost automatically to 75 m.p.h., and ‘remained there wherever conditions made it safe to maintain it, while the maximum of 83 was reached on one or two occasions. The great charm of the car was the way in which it held its speed running quietly and making averages of 50 m.p.h. possible on fast main roads, while on the earlier winding section where we were really hurrying the speed was not much less. Third gear maintains the pace on the steeper main road hill, while second is required only for getting away from slow speeds, such as are occasioned by right-angle bends or road obstructions.

The Lucas P.100 headlamps gave a driving light remarkable both for the length of beam and the even lighting of both sides of the road, and one may therefore safely maintain 75 m.p.h. after dark. Below the headlamps are mounted two anti-dazzle lamps, which are controlled by a finger-tip switch, and with these on and the headlamps extinguished 45 to 50 m.p.h. can still be kept up. High speed of course is not the whole story, so on the following day we continued the tests at a more leisurely pace. Run ning at 40 m.p.h. one could scarcely find a more restful car, for the suspension damps out road-shocks even with the shock-absorbers quite hard, the engine is as silent as one could wish for, and the Dunlop ” 90 ” tyres have lost the whine which was characteristic of the blockpattern tread. On top gear the car runs smoothly down to 15 m.p.h. with the

ignition slightly retarded, and the lever can be left in this position for all town work.

Despite the 10 ft. 4 in; chassis, the cornering ability of the Speed Twenty takes sharp corners in the most surprising way, while its steering lock of 38 feet, which allows it to negotiate comfortably the Monte Carlo ” Figure of Eight ” would be no less welcome on the hair-pins of an Alpine Pass. The steering, which seemed a little low-geared when manceuvring in the garage, suits the car admirably on the open road, and is light and rigid and we liked the powerful caster action, which centres the wheels after a corner with the minimum of effort on the part of the driver. The driving position is an upright one, with the large steering wheel comfortably in the lap, and the central -gear-lever and the substantial hand-brake lever, which is mounted on the forward On the right well clear of the door, come naturally

under the hands. The foot controls are light in action, the telecontrol knobs and the traffic-signal switch are mounted conveniently on the driver’s right, and the dash-board equipment is complete. The driving seat gives excellent support to the thighs and shoulders, but as open car enthusiasts we should have appreciated a little more room on the right when the elbow is raised to indulge in fast driving. There is of course plenty of room when driving normally. There is much of technical interest in the engine and chassis of the 1935 Speed Twenty, and some of the salient points will now be dealt with. The engine of course is a six-cylinder unit with a fourbearing crank-shaft, balanced and fitted with a torque damper at the front end. The overhead valves are pushrod operated, and are each fitted with multiple small helical springs instead of the more usual

concentric pattern, giving quiet operation and freedom from valve bounce. Pump cooling is used in conjunction with a fan, and exterior water passages are used to convey the water to the detachable cylinder head.

Coil ignition is used for starting purposes, the engine is switched then over to the special Polar Inductor magneto. Three S.U. carburettors are used, with a supplementary starting device, the petrol is drawn from the 16 gallon rear tank by two S.T.T. electric pumps, and a reserve tap is fitted under the dash. A leaded fuel such as Pratt’s Ethyl suitedthe engine very well.

Forced lubrication is used for all working parts, and suction and pressure filters are used. A one-shot chassis lubrication tank is mounted on the dash, as are also the fuse box and regulating system for the two-unit constant voltage electrical system, and the handle for the permanent jacks.

Everything under the bonnet has the characteristic high finish of Alvis products, the wiring and pipework is neatly carried out, and the auxiliaries are all accessible.

The single-plate clutch is carried in a bell-housing at the rear of the engine, and the all-synehro-mesh gear-box, which has already been described is separately mOunted and driven by a short shaft. The open propeller shaft is free from whip up, to 6,000 r.p.m., and is fitted with two universal joints, and the bevel-driven back axle has fully-floating shafts.

The chassis is of deep section upswept at the front and carried very sharply over the rear axle, the bottom of the arches thus formed being bridged by detachable bracing pieces. Six carefully lightened pressings form the cross-members,. and these are so tied by struts and the steel ‘floor amidships that the car’s stability at speed is readily understood. Underslung half-elliptic springs are used at the rear, while the front springing is effected by a single transversely-mounted cantilever. The lower ends of the steering pivots are maintained in position by swinging links, and Telecontrol shock-absorbers are used to regulate, at will, the stiffness of the suspension. Each wheel has its own steering rod, which passes through an aperture on each side of the chassis frame to a common bell-crank lever mounted inside the side-member on the ‘off-side, and the bell-crank lever is in turn actuated by a short link from the drop arm.

On last year’s models, on which the track rod was carried underneath the chassis, there seemed a possibility of its being damaged when passing over rough roads, but in the revised lay-out all parts are well-protected, and the connecting links short and rigid. Before leaving the chassis we must not forget the powerful Alvis cable operated brakes, with their 14 in. drums. A special feature Of the design is that all parts are either in tension or compression, with no possibility of lost motion through

torsional whip of cross shafts. The car we tested was fitted with a handsome two-door saloon, One of the series of Special bodies designed by Messrs. Charles Follett and built by Vanden Plas ; and one would not fail to be impressed by the long bonnet, the sweeping lines, and the handsome and

efficient mudguards. The roof level is no higher than the average man’s shoulder, ‘yet in the front a felt hat can comfortably be worn by a six-foot driver. In the back seats the hat just touches, giving six inches of head-room when sitting without a hat. The back seats are well forward of the back-axle and should be as comfortable as those in front. Front and backs seats are comfortably upholstered in leather, there is plenty of leg room at the back, good access to the back seats, and

room for three when the central armrest is folded hack. There is ample luggage accomodation in the sloping tail, and also a tool locker, and a flap can be let down to act as a luggage grid. The Speed Twenty Alvis comes closer to our conception of the ideal sports car than any vehicle which we have handled

for a considerable time, and it was with real regret that we returned it to its Berkeley Street home. We have to thank Messrs. Charles Follett, who are the London distributors of Alvis cars., for an ‘enjoyable week-end ‘s motoring, and no less So Mr. Follett himself, who as a practical motorist of great experience has ably co-operated with the makers in bringing the car to the high pitch of efficiency and comfort which it has reached in its latest form.