A History of the Armstrong Siddeley Car
Part 2—The Post-Vintage Period
As has been seen in the first part of this history, the Armstrong Siddeley was, and still is, built at Coventry alongside aero-engines. Consequently, it is a car respected and in demand in aeronautical circles. Harking back for a moment to the vintage years we are reminded by William Courtenay, in his book “Airman Friday,” that when he was Press and Publicity Director to Sir Alan Cobham’s Air Tour of Great Britain, he travelled 100 to 200 miles a day in a 20-h.p. Armstrong Siddeley two-seater making advance preparations. This car he crashed spectacularly in 1929 on a slippery road at Huntspill, the car ending up in the Post Office parlour. Courtenay persuaded the startled post-mistress to cover the hole in her parlour wall with posters advertising the air show—in which Cobham gave passenger flights in a D.H. 51 10-seater biplane, “Youth of Britain,” powered with a 500-h.p. Armstrong Siddeley Jaguar engine.
The vintage Armstrong Siddeley had valve gear even more closely related to these air-cooled radial aero-engines than to the Puma, which was an in-line overhead camshaft engine. A visitor to Parkside at this period would find cars and aero-engines being assembled literally side by side, and inspection to Aeronautical Inspection Department standards applied to the parts used in the construction of four types of car engine, five types of chassis and five types of aero-engines. Incidentally, in a factory as clean as any racing-car assembly shop, in 1928 the most powerful Armstrong Siddeley was the 47½-litre Leopard 14-cylinder radial, which delivered some 750 h.p. at 1,500 r.p.m. The track-conveyor assembly system was not used by Armstrong Siddeley in 1928, and it is now a legend that if an owner inquired, on taking personal delivery of his new car at Parkside, how long it would take to run-in the engine he would be told politely, “as far as the factory gate.”
Leaving the vintage Armstrong Siddeleys, for 1931 price reductions and other changes were made. The engine of the 12-h.p. six-cylinder model had its stroke increased to 95¼ mm. from 84 mm. (the bore remaining at 56 mm.), so that the swept volume went up to 1,434 c.c. instead of 1,236 c.c., the size of the diminutive vintage Six, although the h.p. rating remained at twelve. This model, smallest of the range, was available with an orthodox three-speed gearbox, but also with a three-speed self-change gearbox. The 15-h.p. Armstrong Siddeley was now offered in two forms, the Short 15 (9 ft. 1 in. wheelbase) with three-speed self-change gearbox and the Normal 15 (9 ft. 7 in. wheelbase) with four-speed self-change gearbox. The chassis had been lowered and a new, more upswept front axle adopted. with redesigned steering pivots and steering gear and the brake camshafts above instead of below the axle. The vee-radiator was set farther back, while the 15-h.p. engine was modified, with a new cylinder head having the plugs almost on the centre line, an air cleaner for the carburetter, while camshaft and valve gear were altered to provide an increase of power coupled to greater refinement. Other detail changes were incorporated, including jacking pads on the front axle. The one-shot system of chassis lubrication was simplified by the incorporating at many points on the chassis of Silentbloc bushes, and the petrol tank filler cap was repositioned and provided with a clamp instead of a screw action.
The 20-h.p. chassis now had a large under-bonnet toolbox and the brake lever on the right, while the Special 20 had a six-shoe instead of a four-shoe braking layout and cantilever instead of ½-elliptic back springs. On both Special 20 and Special 30-h.p. cars a fluid flywheel could be had for £50 extra, and it would be interesting to know if any Armstrong Siddeleys were actually supplied to customers with this Daimler-like transmission. The 1931 cars were distinguishable by the silver finish of the radiator honeycomb but, alas, as the ‘thirties advanced the proud vee-radiators were replaced by cooling elements of flat formation, the vee effect being obtained by the shape of the cowling. Thermostatically-operated shutters were also adopted. In the 1931 Monte Carlo Rally a very fully-equipped Silver Sphinx Armstrong Siddeley won the Coachwork Competition.
The year 1932 saw the introduction of an Economy 12 version of the 1½-litre six-cylinder model, the saloon costing £260, or £35 less than the New 12 saloon, and the introduction of a New 20, of 73 by 127 mm. bore and stroke (3,190 c.c.) with a wheelbase of 10 ft. 11½in., available also in Long 20 form, with a wheelbase of 10 ft. 11½ in. The 15 was now designated a Short 15 or Long 15 according to wheelbase and the former 2,872-c.c. Twenty was continued as the Special 20. This, and the fine old 30-h.p. car, retained magneto ignition, but otherwise coil ignition was adopted. The fluid flywheel appears to have been abandoned but the famous self-change gearbox was used for all models.
At this period Armstrong Siddeley cars, unlike certain other illustrious makes, made frequent and successful onslaughts on competitive rallies. Many prizes were won in the 1932 R.A.C. Rally, the make was represented in the Monte Carlo Rally and in 1933 three exciting new Siddeley Specials, a Long 20, a Sports 20, a Long 15, a Long 15 sports saloon, a 12 saloon and an Economy 12 competed in the R.A.C. Rally, each car carrying four passengers so as to gain extra marks. Mrs. T. H. Wisdom handled the 15 sports and spoke well of its self-changing gearbox, while the new Siddeley Specials were in the hands of C. D. Siddeley, the late Humphrey Symons and S. C. H. Davis.
This new 30-h.p. Siddeley Special was a very sensational new car, which had appeared in chassis form at the 1932 Motor Show. It retained the engine dimensions—88.9 by 133.4 mm. (4,960 c.c.)— which the 30-h.p. Armstrong Siddeley had used ever since 1919, so probably the same crankshaft and connecting-rods, etc., were retained. But crankcase, cylinder block, sump and cylinder head were made of separate castings of Hiduminium light alloy, as were the pistons and connecting-rods. Wet cylinder liners were used, sealed by a copper and asbestos joint at the top and by a copper diaphragm, retained by two castellated ring nuts on liner and cylinder block sleeve, these being tightened by means of a special spanner. About the only ferrous metal parts in this remarkable light-alloy power unit were the crankshaft, which was fully counterbalanced, ran in seven bearings and carried a friction-pattern vibration damper at the front, the camshaft and the valve gear, which incorporated Fabroil timing gears. The stainless steel overhead valves. push-rod-operated, seated upon aluminium-bronze inserts which were screwed, shrunk and then expanded into the cylinder head. The camshaft was driven from the front of the crankshaft and ran in four phosphor-bronze hearings. From it were driven the oil and petrol pumps. The ignition distributor was mounted vertically on the off side of the timing case, with the coil clipped to the cylinder block, and a long shaft with small universal couplings extended from the gear-driven dynamo to drive the water pump. Also on the off side of this externally neat power unit were the sparking plugs, oil filler and float-style oil-level indicator.
The near side of this fine engine was occupied by the manifolding, for a single downdraught Clandel-Hobson carburetter with hot-spotted manifold and two-piece exhaust system. The engine was inclined, so that a single universal-joint was permissible in the long shaft uniting the flywheel with a self-change four-speed gearbox mounted well behind the centre of the chassis. This preselector gearbox had no clutch, the gear bands acting as such. The channel-section chassis frame was double-dropped. amply cross-braced. and sprung on out-rigged ½-elliptic springs. Final drive to the spiral-bevel back axle was by torque tube enclosed shaft, there was worm-and-nut steering with the column adjustable for rake, and the cable-operated Bendix brakes were vacuum-servo-operated. The wheelbase measured 11 ft. 0in., the track 4 ft. 8 in., and the tourer weighed 38 cwt. Pulling a 3.6-to-1 top gear this Siddeley Special, in two S.U. carburetter form (twin S.U.s were adopted for the production cars), could go from 6 to 93 m.p.h. in top gear, attain 70 m.p.h. in third gear and reach 60 m.p.h. front a standstill in 18½ seconds.
The new car was entered for rallies to prove its worth but did not get into production until late in 1933. At the 1933 Motor Show it was exhibited on its own stand, as a black Hooper limousine on a new 12-ft.-wheelbase chassis, priced at £1,360, and a Mach Burlington sports saloon on the 11-ft. chassis, costing £965. The original Siddeley Special was priced at £900, or £650 in chassis form, so that advanced high-performance car was by no means expensive. It was supplied with wire or disc wheels to choice, shod with 6.50 in. by 19 in. tyres, the disc wheels, which were used for a streamlined saloon (AXC 1) driven by C. Wansburgh in the 1934 Bournemouth Rally, being of the kind introduced fifteen years earlier. A Siddeley Special was used by W. F. Bradley, Continental Correspondent of The Autocar, for an A.A. survey of a proposed International Motor Road from London to Istanbul. Nearly 400 were made, in all.
A feature of the Motor Show at around this time Was a perfect scale model Armstrong Siddeley on the Burlington stand in the Coachwork Section–does it exist today? For the 1933 Motor Show Sir John Siddeley introduced a two-door foursome coupé on a short-chassis version of the 12-h.p. model, specially designed “for the daughters-of gentlemen.” It had a vee-fronted radiator shell, wire wheels, handsome lines and a wheelbase of only 8 ft. 1 in. It cost £285.
For the 1934 R.A.C. Rally Armstrong Siddeley struck the happy idea of entering nine cars, all sports Twelves. each painted a different colour and each one starting from a different starting point. The idea was that when all the cars had assembled at the finish they would represent the colours of the spectrum! Also, all were registered in Scotland to obtain the letters ASM.
There were few changes in the range that year but for 1935 new Seventeen and Seventeen Sports models were introduced, with a capacity of 2,394 c.c. The 66.67 by 114 mm. push-rod o.h.v. six-cylinder engine engine gave a maximum speed of 72½ m.p.h. in two-door sports foursome form. and 0-50 m.p.h. acceleration in 17.8 seconds, the new model costing £385; 14-mm. sparking plugs were used and radius-rods located the front axle.
The new Armstrong Siddeley Seventeen proved extremely popular and for 1936 it was improved only in matters of detail, but an entirely new model was added to the range of 12, Short 17, 17 Standard, Long 17, 20 and Siddeley Special models. This was known as the Plus Twelve. It bad an o.h.v. engine of 61 by 95¼ mm., with belt-driven dynamo and water pump. The capacity of the new Plus Twelve was 1,666 c.c. and an increase in power of some 50 per cent. was claimed with no increase in fuel consumption. A horizontal carburetter was used. The top-gear ratio was 5.33 to 1 against 5.5 to 1 for the side-valve Twelve, which was retained, and the price of the new Plus Twelve was £295 as a tourer, £305 as a saloon, the wheelbase being 8 ft. 9 in. The gear ratios were 19.46, 11.28, 7.59 and 5.33 to 1. A very handsome model was the 20-h.p. four-light sports saloon. which cost £585. The Siddeley Special was now made with rather lower gear ratios, top being 3.82 to 1, but in saloon form, priced at £1,050, could do 85.7 m.p.h., reach 50 m.p.h. from a standstill in 13.8 seconds, and go from 30 to 50 m.p.h. in its 5.28-to-1 third gear in 9 2 seconds, returning a petrol consumption of 12-15 m.p.g. The Plus Twelve of the same period would do nearly 65 m.p.h. and 20-24 m.p.g.
Before 1936 a centrifugal clutch was incorporated in the Armstrong Siddeley Twenty and early that year was incorporated in the 17-h.p. model. In January 1936 a Touring saloon version of the Seventeen, priced at £475, was introduced, with the seating within the 9 ft. 6 in. wheelbase. The weight had been reduced by some 150 lb. and D.W.S. permanent jacks and one-shot lubrication were standardised.
For 1937 Sir John Siddeley introduced a car which he hoped would possess sufficient performance to compete with contemporary American vehicles, while retaining the quality and high-grade equipment for which Armstrong Siddeley were renowned, This was the 20/25-h.p. car, which had a six-cylinder 82½ by 114.3 mm. (3,670 c.c.) engine with o.h.v. valve gear, a four-bearing balanced crankshaft, steel connecting-rods with large-diameter big-ends, and Bohnalite Invar-strut pistons. The valves were inclined at a slight angle as on early Armstrong Siddeleys and an S.U. carburetter was used. An enclosed Roper and Wreakes clutch took the drive, via an open shaft, to a Separate rubber and Silentbloc-mounted four-speed self-change gearbox giving ratios Of 14.54, 8.46, 5.57 and 4.09 to 1. The linger-tip gear-control lever was now placed below the steering wheel on the left side. The brakes were Bendix servo with Millenite c.i. drums, and the 20/25 had a wheelbase of 10 ft. 3½ in., or 10 ft. 11½ in. on the long-wheelbase model. The latter pulled a 4.7-to-1 top gear. A saloon was listed at £575, the smart wire-wheeled “Atalanta” saloon at £625. The tyre size was 6.50 in. by 18 in. This was a car of no mean performance, capable of nearly 82 m.p.h., of getting from 30 to 50 m.p.h. in third gear in fractionally over 10 seconds and of accelerating from a standstill to 50 m.p.h. in 15½ seconds. Fuel consumption was 16-18 m.p.g. This fine medium sized Armstrong Siddeley was commendably quick for its size and might have been more successful in Overseas markets had even better servicing facilities been available.
The 1937 range was simplified considerably. The Plus Twelve model Was listed as the Fourteen, the 17-h.p. car was, as we have noted, continued, including a 9 ft. 8 in. wheelbase version with 5.1-to-1 axle ratio, the only other models being the New 20/25 and a Mk. II series Siddeley Special, the lust-named having even lower gear ratios, top gear now being 4.1 to 1 and the length of the short” chassis version increased by 3½ inches. This also constituted the 1938 range of models, which continued up to the outbreak of war. The Siddeley Special was dropped by 1939, in which year two additional models were ready, a Sixteen Six of 65 by 100 mm. (1,990 c.c.) and a Twenty of 75 by 105 mm. (9,780 c.c.), the New 20/25 being continued as the Armstrong Siddeley 25.
It has to be admitted that in complexity of yearly range; if not in interchangeability of engines and chassis, Armstrong Siddeley rivalled a well-known Wolverhampton make! It would he interesting to know how many examples of each model are still in service. In their day the Armstrong Siddeley was favoured by journalists. The Autocar staff. for example, enthused over a Twelve coupé in 1934. while H. S. Linfield. who conducted road-tests for that magazine, used an open Twelve sports tourer, a car which, if it wasn’t capable of much over 60 m.p.h.. he found pleasant to drive and essentially reliable; covering over 18,000 miles in less than seven months, commencing with the 1934 R.A.C. Rally. averaging 22 m.p.g. overall and being at its best 55-m.p.h. cruising speed, and notably fatigue-free. The late Humphrey Symons owned an Armstrong Siddeley Twelve before the war and the late C. G. Grey (outspoken “C. G. G.” of The Aeroplane) had a series of these fine cars. Several Siddeley Specials remain in commission, of which probably the best-preserved is a 1937/8 model owned by Mr. D. W. Brown, a V.S.C.C. member.
Part 3—After the War
Having during the second world war supplied nearly four thousand Cheetah 9 and 10 aero-engines for Use in Anson and Oxford aircraft (this incidentally being the last piston-type aero-engine made by Arinstrong Siddeley), built gearboxes for tanks and other vehicles and constructed torpedo engines, special gyroscopes and other equipment for the Royal Navy, car production was resumed soon after the termination of hostilities. The pre-war Sixteen Six engine was installed in a new chassis having torsion bar i.f.s. This 2-litre Armstrong Siddeley was one of the first post-war cars of entirely new appearance, the slightly vee radiator shell and bonnet front being a continuation of former Armstrong Siddeley lines. The first model comprised the Hurricane drophead coupé and Lancaster saloon. names recalling famous war-time aircraft. The price of both models in 1946 was £1,150, and later that year the Typhoon saloon was added to the range, its price being £1,215. Continuing the use of aircraft names, in 1949 Armstrong Siddeley introduced an additional body style known as the Whitley, the engine of this car having an increased bore size of 5 mm., bringing the capacity to 2,309 c.c. In 1950 the same size engine was used for the Hurricane, Lancaster and Typhoon.
The 1952 Earls Court Motor Show marked the appearance of the first Armstrong Siddeley Sapphire. This luxury car was proved in 1953 to be capable of more than 100 m.p.h. in twin-carburetter form, while its acceleration from rest to 60 m.p.h. was the best of any post-war five-seater saloon road-tested by a contemporary weekly. The 3.4-litre six-cylinder engine of the Sapphire has ingenious valve gear in which inclined overhead valves are operated by push-rods from the normally situated camshaft on the system pioneered in big scale production by Peugeot. The dimensions were literally square, bore and stroke both being 90 mm. The single carburetter engine developed 125 b.h.p. and the twin-carburetter engine gave over 150 b.h.p.
An interesting feature of the Sapphire was that for a time it was available with three different types of transmission, i.e. a synchromesh gearbox, a preselector epicyclic gearbox or a fully automatic gearbox.
Besides the Types 246 and 346 six-cylinder Armstrong Siddeleys, for a time the company listed a four-cylinder model, known as the 234, the body styling of which attempted to provide good driving visibility by having a sharply down-sloping bonnet.
At this year’s London Motor Show the Sapphire was joined by the new 4-litre Star Sapphire with Girling disc brakes on the front wheels, power steering, fully automatic transmission, separate heating for the rare compartment of the luxuriously appointed and very fully-equipped closed body, and the claimed maximum .speed in excess of 100 m.p.h. Thus does this long-established Coventry concern maintain the tradition built up by its former fine—and in the case of the Siddeley Special fast—motor cars. — W. B.