The Front-Wheel-Drive Alvis

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76

Its Development and Racing Career

By G. N. S. Davies

Part 1: The Racing Cars

When, in the early spring of 1925, the Alvis Car and Engineering Company produced the first British racing car to have front-wheel drive, they were living up to their reputation of not being afraid to try new ideas. They had long realised the prestige value of success in open competition, and this, their latest and most adventurous project was, in prototype form, designed purely and simply for sprints and hill-climbs.

Drive via the front wheels, although it had been a talking point amongst engineers for a good many years, was very, very new in practical application, and Captain G. T. Smith-Clarke, Alvis’ chief designer, had little option but to start from first principles. Before the First World War, he had, while working with the Great Western Railway Company, designed an “iron horse,” which, on account of the work it was called upon to do, had to be driven through the front wheels; from this early work, the F.W.D. Alvis was eventually to develop.

The prototype racing car was interesting indeed, and attracted a good deal of attention in motoring circles at the time of its appearance. In order to reduce weight, light alloys were used wherever possible, and even the channel-section frame was of duralumin, with the side-members braced together with duralumin tubes in steel sockets; the complete car weighed only 9½ cwt. The engine, supported by stout tubular bearers, was the well-tried and highly successful 68 mm. by 103 mm., push-rod o.b.v. 12/50 unit. Apart from attention to compression ratio, valve timing and the usual polishing of internals. etc., it was a completely standard unit, placed “backwards” in the chassis. Since the tooling-water entrance and exit were thus at the end of the block farthest from the radiator, some rather “Heath-Robinson” plumbing had to be hastily devised. The car was to be supercharged by means of a Roots-type blower coupled to the nose of the crankshaft. In a single unit with the engine was a bell-housing, containing a conventional single-plate clutch, four-speed gearbox, and bevel final drive and differential. Bolted to the differential casing were the inboard front brake drums.

The front suspension was by means of twin ¼-elliptic springs, a pair on each side of and parallel to the chassis, which carried what was, in effect, a twin de Dion tube with its extremities terminating in forks for the steering swivels. The drive was transmitted via exposed half-shafts, having two universal joints each; one within the brake drum and the outer one being integral with the hub which, in its turn, carried a four-bolt disc wheel. This front-drive and suspension unit was the model from which all subsequent Alvis F.W.D. systems were to be developed.

The rear axle, having very little to do except hold that end of the car up, was of the simplest. It consisted of a straight tube. supported by single ¼-elliptic springs, parallel with the chassis and carrying the rear wheel bearings. The rear brake drums were in the conventional position on the hubs.

The car’s bodywork was brief in the extreme, and consisted of a lengthy bonnet, and primitive bucket seats for driver and mechanic jammed as close as possible to the rear-axle tube. A two-gallon scuttle tank fed fuel by gravity to the 40-mm. Solex carburetter.

The new car made its first public appearance at Kop Hill Climb on March 28th, 1925. Driven by the late Major C. M. Harvey, the car took second place in its class, with a time of 52.6 sec. Major Harvey was number-one driver for Alvis from the very earliest days until they ceased racing in 1930. Driving a racing 12/50 he had won the 1923 J.C.C. 200-Mile Race at Brooklands, at 93.29 m.p.h.

Having made a successful debut with their F.W.D., Alvis now embarked upon a full programme of competition and at the Brooklands Easter meeting on April 13th, 1925, Major Harvey appeared in the works car, which had been painted bright yellow (and named “Tadpole “), but achieved no notable success.

Hill-climbing again, Harvey took two ears to Shelsley Walsh on May 2nd, and in spite of very wet weather gave a good account of himself and the two F.W.D.s. One of the cars had been bored out to 75 mm, and entered in the 2-litre class. For some reason. however. this bored-out version was slightly slower than the standard car, but still managed third in its class, having climbed in 54.4 sec. In the smaller car Harvey had taken f.t.d. in the 1½-litre class, with a climb of 54.2 sec., both cars being unblown for this occasion. Times had been taken over a marked distance through the “esses” and the F.W.D. showed its considerable roadholding and cornering potential by making f.t.d. over this section in spite of the very wet and slippery conditions. In those days, of course, Shelsley had a much rougher and looser surface than is the case today.

At Brooklands again, for the Whitsun meeting, “Tadpole” in two successive races shed the off-side, front tyre, fortunately without damage to car or driver. By the summer meeting, however, a solution had been found to this tyre problem, and Harvey took second place in both the “100 Short” and the “100 Long,” having lapped at 104.41 m.p.h.

Since their win in 1923, the J.C.C. 200-Mile Race had been a “must” for the Alvis works team, and on September 26th, 1925, two of the new cars were brought to the line after the almost traditional frantic scramble to get them ready in time. Both blown, the cars were very fast in practice, but front tyres were causing no little concern, as was the problem of negative castor angle under braking. Mechanics were to be carried, calling for rather mare elaborate accommodation than had been provided in the hill-climb cars, and short pointed tails had now been added. Other alterations included the cleaning-up of the cooling-water pipes, and the fitting of a shaped scuttle enclosing a 25-gallon fuel tank. Drivers were C. M. Harvey and the Earl of Cottenham. Lord Cottenham was to become quite a character in the Alvis pit: his valet would accompany him, bringing a comprehensive selection of suede waistcoats, and, before donning his overalls, his lordship would, at some length, select one which was exactly to his liking.

Harvey drove a fine race, running third for many of the early laps, but shortly after half-distance came into his pit to change a push-rod and rocker, which cost him half-an-hour and caused him to drop from third to 19th place; repairs completed, he was back in the race with the obvious intention of finishing at all costs, which he did. During Harvey’s pit stop Lord Cottenham had moved up into third place, there to remain for fourteen laps. His car, however, had shot its bolt, and he and his mechanic were conveyed down the straight to the Paddock perched on a marshal’s 30/98 Vauxhall, ‘midst many gestures of sympathy from the crowd.

Both retirements were caused indirectly by brake trouble; the rear brakes had been rather hastily devised and fitted, there being no time for proper testing, and those on Harvey’s car had failed early in the race. He had been instructed to drive flat out, which he most certainly did, and had been forced to use the engine as a brake, the consequent over-revving causing the push-rod and rocker failure. In the case of Lord Cottenham’s car, the heat from the inboard brake had done nothing to improve the lot of the differential bearing, which had seized, shearing the short drive shaft, which, in turn, had dropped its broken end into the works, effectively locking the transmission solid.

A good deal had been learnt about front-wheel-drive during 1925, and Alvis’ faith in their new venture was made apparent by their offering to the public for 1926 an addition to their range of well-established 12/50 cars—a supercharged F.W.D. sports car, guaranteed to reach 100 m.p.h., and priced at £1,000. Fitted with a tuned version of the standard push-rod engine, it was to be known as the “12/80.” Very few, however, if any, of these cars were actually sold, which was hardly surprising, in view of the still experimental nature of the car and the not inconsiderable price.

The design department was, however, by no means idle, and an even more interesting racing car was shortly to emerge. On August 2nd the first British Grand Prix was to be held at Brooklands, with another J.C.C. 200-Mile Race on September 25th, and with these two events particularly in mind, the design and racing departments concentrated almost entirely on preparing and testing a new car. The cars were to comply with the Grand Prix formula of 1926/7, which called for an engine capacity limited to 1,500 c.c., superchargers being allowed. Minimum weight was to be 700 kg., and minimum body width 31 in. No mechanics were to be carried, and the driver could sit centrally; this provision being made to allow the inclusion of American Indianapolis-type cars.

Following the trend in racing engines at that lime the new Alvis unit was a straight-eight, of 55mm. by 78.75 mm. bore and stroke, giving 1.496 c.c., with the top half of the crankcase, cylinder block and head all cast in one piece. The combustion chambers were flat-sided, and the valve layout was unusual, the valves being horizontal, and opposed to each other, The exhausts seated in the metal of the head, while the inlets were in detachable cages. They were operated by two high camshafts, one on each side of the engine, and short vertical rockers, each of which was independently mounted to simplify the changing of valve springs. Twin B.T.H. polar-inductor magnetos provided the sparks, each serving four cylinders, and the Roots-type blower, driven from the crank, projected backwards into the cockpit. The crankshaft was of circular web type, and was supported by five plain main bearings. The con.-rods were of duralumin, with plain big-ends, the duralumin providing the actual bearing surface. Lubrication was by dry sump, twin pumps feeding the crankshaft and the two camshafts, which were supported by three ball-and-roller bearings apiece. No flywheel was considered necessary, in view of the circular crank webs, and power was transmitted via a multi-plate clutch of quite small diameter to the gearbox and final drive. Transmission, final drive and suspension were much the same as on the earlier cars, but the chassis was now of pressed steel, of very deep section at the front, where all the weight was concentrated, but reduced considerably behind the scuttle, and tapering still more into the flat-pointed tail. A massive bulkhead-cum-cross-member gave rigidity to the front of the chassis, and also acted as a front engine mounting. In order to lower the centre of gravity, fuel and oil tanks were carried alongside the engine, slightly below the axle line, the tail being quite empty. Considerable attention had been paid to streamlining the body; the undertray was perfectly flat, the only components protruding into the air-stream being the wheels (still of four-bolt, disc type), axle extremities, and rear Hartford shock-absorbers. The wide radiator was covered by a sloped cowling, giving the car a very business-like appearance.

As the date of the British Grand Prix approached it became all too obvious that even if the car could be made ready in time, adequate testing was going to be almost impossible. And so it was to be; a single car was entered, with Major Harvey as driver. He did, in fact, practise, but trouble developed—hardly surprising in so new and untried a car—and the Alvis was a non-starter.

The J.C.C. 200-Mile Race was to take place on September 25th, which gave the works team none too much time to prepare. It did prove possible, however, to give one car a trial run at Shelsley on September 4th and, conducted by Harvey, it climbed very well, though it was not among the fastest owing to unsuitable gearing. Acceleration, however, was impressive, and the rear wheels were seen to be snaking all the way up the final straight. One of the early four-cylinder cars was also entered, and with this car Harvey took third fastest in the 1½-litre class, with a climb in 53.6 sec.

Two cars were entered for the 200-Mile Race, drivers being again Harvey and Lord Cottenham. The regulations were slightly modified in that crash hats were now compulsory, and no mechanics were to be carried; this latter being the result of accidents in the previous year’s race, in which two mechanics had been hurt. The cars now had their nose cowlings removed to improve cooling, and the tails housed 35-gall. petrol tanks.

Once again, that particularly nasty gremlin who concentrated his energies on Alvis F.W.D.s appeared in the race. In the early stages Harvey, who had been driving a splendid race, found himself baulked by a Fiat while coming through one of the artificial corners, went into a violent slide, made worse by the weight of fuel in the tail, and found himself marooned on a sandbank. Having no mechanic to help him restart, he had no option but to retire. Lord Cottenham, finding his engine completely without oil pressure, had left the car on the other side of the course and walked back to retire. This was particularly unfortunate, since when the mechanic went out to collect the car he found that the trouble was caused by a fractured flexible connection, which he repaired in less than ten minutes, driving the car back to the paddock.

For 1927 Alvis’ racing department concentrated their energies on preparing cars for two races only: the second British Grand Prix on October 1st, and the 200-Mile Race a week or so later. The early push-rod, four-cylinder cars had now been dropped, and no F.W.D. car was listed for sale. The results of lack of time for adequate testing and preparation were very fresh in people’s minds and it was hoped, by concentrating on two events only, to prevent a recurrence of the previous year’s troubles. An additional difficulty, ever present through Alvis racing history, was dire shortage of ready cash, and many and various were the devices used to circumvent this difficulty.

The straight-eight Grand Prix cars, around which all the works team efforts were to revolve during 1927, had been completely redesigned since the previous year. The engine, although retaining its non-detachable head, now had hemispherical combustion chambers and valves inclined at 90 deg., operated by twin overhead camshafts, with dashpots enclosing the valves and springs. As on the first eight-cylinder engines, twin polar-inductor magnetos were used, one driven from each camshaft. To drive the camshafts, one huge idler pinion, over a foot in diameter, transmitted the drive from the crankshaft to the camshaft pinions. The supercharger, of Roots type, was gear-driven on the off side of the engine, and the inlet manifold was cast into the cylinder block itself. Within the sump were no less than four gear-type oil pumps, two of them scavengers which passed oil to an oil cooler, mounted beneath the very wide squat radiator. These two pumps operated one at each end of the sump, to eliminate any chance of oil starvation due to surge. The two feed pumps (one high, one low pressure) dealt one with the crank, and the other with the camshafts and timing gears. This new engine was a great improvement on its horizontal-valve predecessor, in which it had been found impossible to fit valves of adequate diameter and at the same time provide the pistons with sufficient clearance.

A multi-plate clutch was again used, with no flywheel, but the final drive had undergone many changes. The differential, to which were bolted the inboard front brakes, came between the clutch and the gearbox, which protruded right out in front of the car. This arrangement caused some additional complication, particularly of the clutch withdrawal mechanism, but had the advantage of making the whole unit very compact, and of concentrating the weight over the front wheels.

Rear suspension was much the same as on the previous cars, but the whole of the front end had been redesigned. The twin de Dion tube had now disappeared, and the front wheels were independently suspended by means of eight transverse ¼-elliptic springs, four on each side, damped by twin Hartford shock-absorbers. The four-bolt disc wheels were retained, mounted on hubs which must have cost a small fortune, being machined from solid billets. The spacers through which passed the spring anchorage bolts were aluminium castings, machined all over. These spacers, together with two channel-section cross-members below, and two angle-sections above the chassis, made the front end very rigid.

The steering-box was, of course, centrally placed, with the shaft carrying the worm wheel emerging on both sides of the car. To each end of this shaft was attached a drop arm, one pointing upwards and the other down; from these, a separate drag-link passed forward to each wheel, the off-side one above the hub and the near-side one below it.

In view of the very low scuttle height, the space available for a radiator of adequate cooling area was limited, and a very wide, squat core had to be used. Twin fuel tanks of 20 and 25-gall. capacities were carried in the scuttle and tail, respectively, the tail tank to be emptied first.

In spite of months of hard work, it was again all too obvious that the Alvis would only just be ready for the British Grand Prix on October 1st. In view of the fact that there would be no time to do any proper testing, withdrawal from the race was considered but, since theirs was the only British works entry to oppose the all-powerful Continental teams, Alvis decided to try to get the car to the line somehow, if only to show the flag. Once again, however, the gremlin reared his ugly head; Major Harvey broke a piston in practice, a broken piece of which wrecked the oil pump, and in spite of the team working all Friday night the car was a non-starter.

For the 1927 200-Mile Race Major Harvey and the Earl of Cottenham were again down to drive two works cars, but Lord Cottenham withdrew at the last moment, giving “family matters” as his reason for so doing, his place being taken by George Duller. Slight alterations had been made; the oil coolers had been removed, since they had proved to be somewhat vulnerable, and hardly necessary in any case. With Harvey’s retirement in the previous 200-Mile Race in mind, starting handles had been fitted, to enable the drivers to restart single-handed if necessary; mechanics being, of course, no longer carried.

Neither driver had a chance for any real practice, since the cars only arrived at Brooklands on the morning of the race, and there was no time to get them properly run-in. They did, however, manage a few laps on the outer circuit, and the cars were certainly fast: Duller had what seemed to be the better car, and lapped the outer circuit at around 120 m.p.h.

Both cars were all but written off immediately after the start, when Duller went into a corner too fast, with Harvey right on his tail, and slid violently. Harvey managed to dodge him, however. and a multiple pile-up was averted. Neither car was running as it should, and Harvey came in with a burnt piston soon after quarter-distance. Duller, although not on all eight cylinders, pressed on and, by splendid and determined driving, managed to work his way into fifth place, until he, too, was forced to retire with the same trouble.

So came to an end the last 200-Mile Race in which Alvis were to participate as a works team, and the cars were the last pure racing models to emerge from the works. It is fortunate that one example, Duller’s car, still exists.

After all their years of effort, Alvis deserved greater success than it had been their lot to receive, but the greatest, and ever-present, stumbling block was lack of adequate funds; such situations are not unknown in England today.