Alvis 1933

Firefly 12 4 cyl., 1496 cc, 50 bhp  
wb: 9 ft 10½ in. 4 light saloon  
  6 light saloon  
  drophead Coupé  
  sports tourer  
12/50 TJ 4 cyl., 1645 cc, 50 bhp – discountinued (3616 ex.)
wb: 9 ft 4½ in. saloon  
  drophead Coupé  
  4-seater sports  
  2-seater sports  
Silver Eagle 16 6 cyl., 2148 cc  
wb: 10 ft 3 in. Atlantic saloon  
  coachbuilt saloon  
  2/3-seater sports  
  tourer  
Silver Eagle 20 6 cyl., 2511 cc  
wb: 10 ft 3 in Atlantic saloon  
  coachbuilt saloon  
  Mayfair 4-light saloon  
  Mayfair 6-light saloon  
wb: 11 ft. Limousine  
Speed 20 SA 6 cyl., 2511 cc, 87 bhp – discountinued
wb: 10 ft 3 in. sports saloon  
  drophead Coupé  
  sports tourer  
Speed 20 SB 6 cyl., 2511 cc, 87 bhp – new model
wb: 10 ft 3 in. sports saloon  
  drophead Coupé  
  sports tourer  
Crested Eagle TE 6 cyl., 2148 cc – new model
wb: 10 ft 3 in. 4 light saloon  
  6 light saloon  
  limousine  
Crested Eagle TD 6 cyl., 2511 / 2762 cc – new model
wb: 11 ft 0 in. 4 light saloon  
  6 light saloon  
  limousine  

Great Britain

Motor Sport October 1932
Sports cars for 1933.

Alvis Car and Eng. Co., Ltd., Coventry.
"12/50" and "12/60" : 4 cyl., 69 x 110 mm., 1,645 c.c., 11.9 h.p.
"Firefly" : 4 cyl., 69 x 100 mm., 1,496 c.c., 11.9 h.p.
"16.95 Silver Eagle" : 6 cyl., 67.5 x 100 mm., 2,148 c.c., 16.95 h.p.
"20 h.p. Silver Eagle" : 6 cyl., 73 x 100 mm, 2,511 c.c., 10.82 h.p.
"Speed Twenty" : 6 cyl., 73 x 100 mm., 2,511 c.c., 19.82 h.p.
Stand No. 56.-Exhibits: "Speed Twenty" chassis, 4-seater and saloon; "Firefly" chassis, saloon coupe and 4-seater and "Silver Eagle" models.
The 12/50 and 12/60 models remain unaltered for 1933, the chief features of the car being the push rod o.h.v. engine, with 3-bearing crankshaft and aluminium alloy pistons, coil ignition, single plate clutch, four speed gear box, right-hand change, open propellor shaft, and semielliptic springs front and rear. The tank capacity is 10 gallons, wheelbase 9ft. 4ins. and track 4ft. 2ins. The 12/60 sports model differs from the 12/50 in having a higher compression ratio, two carburettors, close ratio gear box and special rear springs.
An entirely new model, the "Firefly" has been introduced, the principal features of which are as follows : 11.9 h.p. 4 cylinder engine, 1,496 c.c. 3-bearing crankshaft, connecting rods with special anti-friction bearings die cast into position, aluminium alloy pistons, Duplex chain driven camshaft and auxiliary drives, lubrication by rotary geared pump, coil ignition, single plate clutch, 4 speed gear box with central change and silent third gear, tubular cardan shaft, full floating rear axle, 14in. brake drums, semielliptic springs all round, ulerslung at rear, dropped frame, 14,5 gallon rear tank, 9' 10½" wheelbase, 4' 6" track. The whole car is built on the lines of the "Speed Twenty" and is very attractive in appearance.
The "Silver Eagle" 16.95 h.p. and 19.28 h.p. models are high grade luxury cars, intended for comfort and quietness rather than speed, although their performance, in view of the weight of the bodies, is remarkable.
The "Speed Twenty" has found to be so popular that it is being continued for 1933 absolutely unchanged, a great tribute to the forethought given to its initial design. The engine is a 6 cyl. of 2,511 c.c., with push rod operated o.h. valves, giving a very high performance to the car on the road, and a maximum speed of over 90 m.p.h.
PRICES. "12/50" and "12/60" : 2 seater £450; Coupe, £435; Saloon, £495.
"Firefly" : Open 4 seater, £475; Coupe £475.
"16.95" and "20.98" "Silver Eagle" : Saloon £695 and £775.
"Speed Twenty": Open 4 seater £695, Saloon £825.
The Speed 20 was first introduced in 1932 and with 90 mph from 2½ litres was a sensation at the time. The SB model introduced in September 1933, differ from the original SA design in having independent front suspension and all-synchromesh gearbox. The six-cylinder OHV engine develop 95 bhp at 4000 rpm.
Motor Sport February 1933
A TECHNICAL DESCRIPTION OF THE ALVIS "FIREFLY"

Firefly Sports Tourer
THE appearance of the "Speed 20" early in 1932 was an event of the first importance for fast motorists. The low centre of gravity made possible by the double drop frame, the excellent brakes and unit construction of engine and gearbox were all highly successful developments. All these features and various others which will be enumerated were used in bringing the four-cylinder "Firefly" into a position as advanced as that of the six cylinder car.
The cylinder dimensions of the "Firefly" are the usual 69 and 100 mm., giving a capacity of 1,496 c.c., with an R.A.C. rating of 11.9. The cylinder head is detachable, and the cast-iron cylinder block is bolted to an aluminium crankcase. The overhead valves are operated by push-rods and the rockers and ball-ends are positively lubricated. A semi-downdraught S.U. carburettor, supplied by a petrol pump, is bolted to a V shaped induction pipe, which is in contact with a flange on the centre exhaust branch to form a hot-spot. The exhaust gases are led away from the front end of the engine, avoiding any possibility of overheating in the driving compartment. Coil, distributor and plugs are all accessible on the off-side of the engine. The distributor embodies an automatic advance and retard with an additional hand control on the steering column.
The aluminium alloy pistons carry 2 compression rings and 1 scraper. The bigend bearing surfaces, which are of white metal, are cast integral with the steel connecting rods and the three bearings for the balanced crankshaft are carried in webs extending the whole width of the crankcase. The camshaft is driven by chain from the rear end of the crankshaft, a lay-out which theory approves, but which finds a place on all too few cars. Its practical value is shown by the fact that on engines fitted with this rear dual location timing chains last at least four times as long as when the drive is taken from the forward end. The torque damper which was fitted to the 12-60 engine has been found unnecessary on the "Firefly" and is therefore not fitted.
The engine is cooled on the thermosyphon system, and the heat is dissipated by a large honeycomb radiator. The cooling water passes from the block to the cylinder-head through an aluminium casing at the rear of the engine, and there are no passages which depend for their tightness on the cylinder-head gasket. The flow of all the cooling water along the whole length of the engine and back, and the generous water spaces round the hot parts of cylinder and head should give complete freedom from local overheating, a most important consideration in the case of a small high-efficiency engine.
The oil pump is gear-driven from the camshaft and forces oil through a Tecalemit filter to the various bearings and there is another filter on the suction side. A gallery along the side of the engine supplies the main bearings with oil, whence it travels to the big-ends through the drilled crankshaft. Filter and oil filler are accessibly placed on the near side of the engine.
Engine, clutch pit, and gearbox are bolted together to form one unit of immense strength and the whole is flexibly mounted at three points, one in front of the engine, and the other two brackets at the rear end of the clutch housing. A single dry-plate clutch is used, and the four-speed gearbox has a silent third gear and a centre ball change brought back so that the lever is under the driver's left hand. The speedometer is driven from the gearbox.
The propellor shaft is of the open type, tubular, and of large diameter. It is fitted with Hardy Spicer joints front and rear. The final drive is by spiral bevel, and the fully floating rear axle, a feature not often found nowadays, should ensure a long life for this much-stressed part of the transmission.
The new Alvis "Firefly" in chassis form.
The chassis frame is double-dropped following the well-known lines of the Speed Twenty, but the dimensions are naturally somewhat less, the Firefly's wheelbase and track being respectively 9ft. 10½ins. and 4ft. 4ins. against 10ft. 3ins. and 4ft. 8ins. on the larger car. The double-dropped frame allows of a low floor line without restricting head room, brings down the centre of gravity very considerably and allows plenty of movement for the axles without striking the side members The latter are braced by six cross members, most noticable of these being the pressing which unites the side members at the front mounting of the rear springs. Half elliptic springs are fitted all round, with Hartfords back and front, those at the rear being carried parallel with the axle. A Marles-Weller steering box is used, with an unusually long drop arm.
The brakes are identical with those fitted to the "Speed 20" and operate on 14 inch drums. The shoes are expanded by a floating lever which carries two pins. When the lever is moved by the control cable, one pin bears against the end of each of the two shoes. The floating layout ensures that each shoe exerts the same pressure, and the brakes have a self-energising action. Another good feature is that there is no joint or lever exposed to dirt and wet. A knurled knob projecting through the floorboards at the driver's side operates a master-adjustment, while there is an adjustable cable stop on each brake-cable to allow the effect of all four brakes to be equalised.
Wire wheels with knock-on single centre nuts carry 30in. by 5in. Dunlop tyres.
The electrical equipment is of the normal type, the dynamo being driven from the timing chain. Rotax head lamps. are used and the two six-volt batteries are arranged one on either side of the propellor shaft. The lights are controlled by a lever in the centre of the steering wheel, and the switching mechanism is accessibly mounted on top of the steering-box.
Though the chassis is shorter than that of the "Speed 20," the 4 cylinder engine of the Firefly actually allows a greater amount of space to be devoted to passenger accommodation than on the larger car. A particularly handsome saloon with a sunshine roof, and also a drop-head coupe are offered at £495, while the open four-seater costs £20 less. A road-test of this latter model appears elsewhere in this issue, and shows that the traditional high performance and comfortable travel which one expects in an Alvis car has been more than maintained.
Motor Sport February 1933
A WEEK-END WITH THE ALVIS "FIREFLY"

The Alvis "Firefly" is a beautifully proportioned car in saloon form, and is extraordinary roomy for a 12 h.p. machine.
THE increasing standardisation in the design of modern cars has naturally led to similarity in control, so that in the ranks of cheaper cars there is very little to chose between them in this respect. This state of affairs is largely brought about by mass production methods, and does not apply to those cars which are built, not to a price, but to the designer's ideal.
This train of thought passed through the writer's mind when he first took over an Alvis "Firefly" Sports Saloon for a week-end test recently. His previous mount had been a popular light six, which did its job adequately without revealing a trace of character and without making any demands on its driver—except at high speeds, when concentration was required to remain in a straight line. What a difference in control was needed for the "Firefly," and with what correspondingly greater pleasure! Alvis cars have always been renowned for a rock-like solidity and strength, and this new model is no exception to the rule. Tautness and robust construction are one's first impressions of the car, and one felt unmistakeably that it was descended from the famous old 12/40 model of ten years ago.
For sharp turns at walking pace on full lock, the writer found the steering rather heavy, especially in comparison with the light six he had previously been handling. But you can seldom have it both ways. The effort required at low speed was more than counter-balanced by the inherent steadiness of the Alvis when travelling fast over a rough surface, a circumstance in which the light six would be a "handful." The steering is high-geared, with pronounced caster-action, so that cornering is at all times safe and controlled. After all, the majority of a "Firefly's" life will be spent in cruising at 50 m.p.h. on main roads, and at this speed the steering is effortless and at the same time positive.
Suspension can make or mar the steering qualities of a car, so that a description of one must inevitably lead to an account of the other. The "Firefly" holds the road beautifully at all speeds, and although the shock absorbers were adjusted for fast work, no discomfort was experienced at low speed. Undoubtedly the long wheelbase, 9' 10½'' is partly responsible for this, and indeed the general riding qualities of the car belong to a machine of greater size and horse-power.
It is common knowledge that a car, to be safe at its maximum speed, should be so designed that the chassis can hold the road perfectly at speeds a good deal higher than its actual maximum on the level, thereby providing a margin of safety. In order to test this margin of safety it is our custom, whenever possible, to take test cars to a certain stretch of road, straight and downhill. Here the car is driven at a higher speed than can be hoped for on the level, and a thorough test of the road-holding, and incidentally, the engine of the car under review obtained. The Alvis "Firefly" came through this trial with flying colours. 70, 75, 80 m.p.h. was registered by the speedometer, and at this speed the car held the road like the proverbial leech.
As for the engine, we had already demonstrated its readiness to turn over smoothly at 4,700 r.p.m. on third gear, so that we had no qualms about its safety. The speedometer, by the way, is accurate.
A 12 h.p. saloon with the dimensions of the Alvis "Firefly" naturally requires a long stretch of road in order to reach its maximum, and on such a highway we succeeded in reaching a speed of 75 m.p.h., with a full complement of driver and three passengers. On any good main road 70 m.p.h. can be attained, but special conditions are necessary for the extra 5 m.p.h. to be gained. The "Firefly" cruises without any effort at 50 m.p.h.
The engine is flexible at low speeds providing that it is not required to pull too hard, and the ignition control on the steering wheel quadrant enables satisfactory results to be obtained. An owner of a "Firefly" will not be of the type of driver who wants to creep about on top-gear, and will probably prefer to use the gear-box, as should be done with a car of its specification. By dropping down to second the car accelerates well even from walking pace, and on this gear a maximum of 38 m.p.h. is possible. Third is on the low side, which benefits the get away from usual town traffic. 50 m.p.h. was reached in comfort on several occasions, although it is probably better to change up at about 45 m.p.h. for the fastest acceleration.
The gear change requires a little practise in order to become completely at home with it. Precise timing has to be effected for quiet changes, the slightest delay making it impossible to engage the gears. Once the correct pause has been learned, however, no difficulty is presented at all. Unusually, changes down can be made easier at first than upward "gearshifts," that from top to third being particularly delightful.
The brakes are well up to their work, and although they require considerable pressure for maximum operation, they can be applied to the exact amount necessary. The foot-pedal has a large surface, which adds to the driver's sense of security, and indeed the angle of all the pedals has been carefully designed—a point not as common as one would imagine.
The body of the car we tested was a coachbuilt saloon of generous proportions and very pleasing lines. Four wide doors enabled the interior to be reached without any acrobatic contortions, and the driving position was beyond criticism. A large boot at the rear provided plenty of room for luggage, and altogether the car was admirably suited to long distance touring. Our only criticism of the body was that the front doors, being hinged in the middle of the car, allowed a draught to enter the front cockpit, while another breeze seemed to find its way into the rear compartment from the foot-wells and from under the seat. These faults, however, may very well be only found on the actual car tested—and in any case should not be difficult to remedy. The equipment was complete, the Rotax headlamps giving a splendid driving light, and the British Berkshire screen-wiper coping satisfactorily with a blizzard of snow and sleet.
The price asked for the Alvis "Firefly" saloon is £495, and when one considers the strength of its construction, its lively performance, low tax, and the famous Alvis wearing qualities, the worth of the car can be readily appreciated.
Motor Sport February 1933
THE ALVIS "SPEED TWENTY" FOR 1933

ONE of the most successful sports cars of 1932 was undoubtedly the Alvis "Speed Twenty." Its performance was terrific, both in acceleration and in maximum speed, and the open sports model could be purchased for £695! No wonder the car was popular!
Many new models are altered after a year's use in private owners' hands, but so much forethought had been expended on the design of the "Speed Twenty" that the car remains absolutely unchanged for 1933.
Here are a few details of the specification of the car. The engine has six cylinders of 73 x 100 mm., giving a cubic capacity of 2,511 c.c. The head is detachable, and the water spaces are particularly generous, in order to provide really effective cooling. An interesting point is that the gasket is not used to make a water-joint, for there are separate passages made between the cylinder block and the head. The four-bearing crankshaft is heat-treated and balanced, and a vibration damper ensures complete smoothness throughout its range of revolutions (it can turn over at 4,500 r.p.m.). The pistons are of special alloy, and the con-rods have bearing-surfaces die-cast into position. Situated at the rear of the engine, the camshaft and auxiliary drives are operated by Duplex chain, and lubrication is by pressure to crankshaft main and big end bearings, and to the valve rockers and push rod ends.
Petrol is drawn from a 14½ gallon rear tank by an A.C. mechanical pump to three S.U. carburettors. Ignition is by B.T.H. polar inductor magneto as well as special coil for starting in case the magneto should fail to function, which is unlikely.
A single plate clutch and 4 speed gearbox transmit the drive to spiral bevel rear axle and thence to the road wheels. 14 inch brake drums, semi elliptic springs, one shot chassis lubrication and a double dropped frame complete the specification of one of England's outstanding sports cars.
The low chassis frame gives coachbuilders plenty of scope for bodies of beautiful lines. Vanden Plas (England) 1923, Ltd., have always been noted as specialists in sports coachwork and their range of bodies on the "Speed Twenty" Alvis are well up to their usual standard. Their models are a very good looking open four-seater, a two-seater sports, and a saloon. Messrs. Thrupp & Maberley, Ltd., turn out a beautifully finished sports saloon, which is entirely in accordance with this firm's reputation for luxurious coachwork on expensive chassis. Finally, the Mayfair Carriage Co., Ltd., produce a very striking saloon with beautiful lines, and here again a very high degree of finish has been obtained.
Motor Sport February 1933
Motor Sport February 1933

Speed Twenty

Speed 20 tourer
Motor SportJune 1933
New Coachwork on the Speed Twenty Alvis.

Some minor improvements have recently been made to the coachwork of the Alvis Speed Twenty by the Alvis Car & Engineering Co., Ltd., of Coventry. On the Charlesworth saloon greatly increased luggage space has been provided, while the lines of the open 4-seater have been completely redesigned, and running boards are now fitted, and a normal type hood instead of the disappearing one previously used. In addition, a new coupe has been Introduced, with coachwork by Charlesworth, priced at £825.
Motor Sport February 1933

Silver Eagle (?)
 

           
           

   

Races:
  Event: Entered: Raced: Finished: Best results:
11.03.1933 Brooklands First Sprint Handicap - - -   C. G. H. Dunham Speed 20 2nd
11.03.1933 Brooklands Fourth Sprint Handicap - - -   C. G. H. Dunham Speed 20 3rd
16.04.1933 Brooklands Junior Short Handicap - - -   C. G. H. Dunham Speed 20 1st
16.04.1933 Brooklands Lightning Long Handicap - - -   J. H. Parsons 1,513 c.c. (s) 1st
06.05.1933 International Trophy 1 1 0   J. D. Benjafield Speed 20 dnf
05.06.1933 Brooklands Junior Long Handicap - - -   J. H. Parsons 1,513 c.c. (s) 3rd
France 17.06.1933 24h Le Mans       7 Gunter / Benjafield 2511cc dns
01.07.1933 Canada Trophy (British Empire Trophy) 3 3 1   Frank Hallam FWD 1,492 c.c. (s) 1st
01.07.1933 British Empire Trophy 2 2 1 5 Frank Hallam 8/15 FWD 5th
Rallies:
  Event: Entered: Raced: Finished: Best results:
21-25.01.1933 Rallye Monte Carlo 3 3 2 22 Runciman   31st
          73 Crisp   38th
  31.07.1933 Coupe des Alpes   1 1   Miss M. D. Patten 2,511 cc 2000→3000 14th

No. 73 Jack V. Crisp drove his Alvis from John o'Groats and took 38th place in RMC.