The Emeryson Special
A very advanced Amateur-Built 1,100 c.c. Racing Car that was successful on its first appearance. Two-stage supercharging and independent suspension front and back.
The Emerys, father and son, have produced in the latest Emeryson Special a racing car of which a specialised factory might well be proud. Working in a small shed at Maidenhead they have evolved a 1,100-c.c. engine with two-stage supercharging and installed this in a modern tubular all-independently-sprung chassis. On its very first appearance, at Gransden, driven by Eric Winterbottom, the Emeryson easily won the First All-Corners' Handicap at an average speed of 68.17 m.p.h., reaching nearly 140 m.p.h. on the straight and proving stable and very controllable round the corners.
Paul Emery was with the Alta Company before the war and his first competition car was the Gvvynne-engined Emeryson Special, which gained quite a number of successes. During the war he acquired Fitt's amazing twin-Centric-blown Hudson Special after it had been blitzed and this he has rebuilt into a very potent sprint car, which is also perfectly tractable in London traffic. We had a short run in the Hudson on the way to view the Emeryson and were profoundly impressed by its ability to accelerate from a crawl up to 90 or so m.p.h. along very short pieces of straight-going without using the lower gears and to stop with equal facility. It is possible that Emery may dispose of this car in order to do justice to the racing car and anyone in need of a car which makes long runs seem child's play and which is ideal for sprint events might care to bear this in mind. His father has been largely instrumental in working out the details of the Emeryson. In the early nineteen-twenties he worked for Kaye Don on his A.C. and similar cars and up to the war he was responsible for Winterbottom's 1,100-c.c. Alta, which could lap the Brooklands' outer-circuit at around 120 m.p.h.
The engine of the Emeryson, amazingly enough, is a practically standard 1934 twin o.h.c., 1,104 c.c. Lagonda Rapier unit, reduced to 1,087 c.c. Apart from pulling it apart and very carefully assembling it, nothing drastic was done other than to fit 1/16th-in, oversize inlet valves (the port area remained unchanged) and to supercharge it. In the original engine the compression ratio was 8 to 1, and it has not been lowered, although boost at 22 lb./sq. in.is now applied.
At first a single Marshall-Roots supercharger was tried, then a supercharger from a 1,750-c.c. Alfa-Romeo was substituted, the results being practically identical. Then it was that these enterprising engineers decided to attempt two-stage boosting. From the front of the crankshaft an extension shaft was driven via a coupling composed of two sprockets united by a wrapping of roller chain. From this shaft dual roller chain drives were taken, one to the Marshall blower on the near side, another to the Alfa-Romeo blower on the off side, the blowers being mounted side by side. This a of two-stage boosting was found to give remarkable acceleration, but gave rise to various troubles, notably over heating of the inlet tract. It was decided that the Alfa-Romeo blower was unsuitable, so a Marshall cabin blower, with leather seals, was substituted. Using the original Marshall I.Z.85 blower for first-stage, driven at just above 11 times engine speed, and the Marshall cabin blower, driven somewhat faster, as second stage, the results have been immensely satisfactory, and this installation reflects the greatest credit on the painstaking Emerys. The blowers were tested in the chassis to determine correct speeds of drive, using a pressure gauge on each blower, and the necessary sprockets to achieve the speeds decided upon were found by searching the breakers' yards! The boost now achieved is 22 lb./sq. in. at 6,500 r.p.m. The first supercharger draws from a large S.U. carburetter formerly fitted to Winterbottom's Alta. Inlet temperature is now practically zero, and the engine is surprisingly tolerant as to carburetter setting, which suggests that both blowers are doing their job very thoroughly.
The inlet system is distinctly interesting and reminiscent of that used on Lockhart's famous 164-m.p.h. Miller. At first a simple Y-manifold was used, but an obscure ignition trouble produced symptoms suggestive of faulty mixture distribution, so a new induction system was devised. It comprises an external four-branch inlet manifold, fed by another pipe directly beneath it, through two ports in its under-surface. The lower pipe is fed, in turn, from the second-stage, or off side blower, through a large-bore pipe. Both blowers are lubricated from the engine pressure system, a drip-feed above each controlling the supply of lubricant. There is a four-branch exhaust manifold on the near side of the head. Before we leave the engine, one other modification must be mentioned. In standard form the dynamo, on the off side, drove the magneto. As no dynamo was required on the racing car, a water-pump from a 3-litre Sunbeam was obtained and bolted in place of the dynamo. This not only provided an effective magneto drive, but also gave double the rotor capacity of the Rapier water pump. The magneto now in use is a Scintilla N.M.4 and K.L.G. 690 14mm. plugs are employed, although another grade of plug is likely to be tried in future. The water off-take pipe leaves the top of the head at the front and merges into tapered "delivery-box" like that used by the racing Mercédes-Benz cars, to assist the flow.
To obviate gasket troubles, which the high boost might have caused, very clever use is made of Will's Pressure Rings to seal each bore. Although one side of each ring is exposed to the burning gases, no failures have been experienced, and the same rings have actually been replaced and used again after the head has been lifted for inspection. Specialloid pistons have given every satisfaction. It says much for the Rapier engine, which first appeared in 1934, that it has stood up so well to two-stage boosting. Its normal helical oil pump has proved entirely adequate, giving 100 lb./sq. in. pressure, even when the oil is hot. Castrol "R" lubricant is used, also fed to the blowers, of course, and the engine is run on Formula 1 fuel, which it consumes at the rate of approx. 5 m.p.g. Rubber engine mountings are used.
This truly remarkable engine is installed in a chassis no less creditable as an example of what the Emerys can achieve by way of immense energy and enthusiasm to off-set a not excessive expenditure of hard cash. Incidentally, effective and efficient as this Emeryson Special is, many parts that have gone to the making of it have been adapted from scrap and all the machining has been done in the home garage by Emery senior, on a 5-in. I.X.Z. lathe.
The chassis is of tubular construction, the substantial tubular side members being united by four main tubular crossmembers of like diameter, of which the rear-most accommodates the torsion bars for the rear suspension assembly. At the front two smaller-diameter tubular cross-members, one mounted above the other, carry the front suspension unit. This is none other than a Gordon Armstrong coil spring and swinging arm assembly from an old Singer. Needless to say, its geometry has been modified and the steering is now controlled by a separate drag link on each side. These drag links are cleverly actuated from a steering box, mounted centrally at the foot of the steering column, containig, a G.N. steering bevel working, as it were, two G.N. steering crown wheels, each connected to its own drop-arm. To provide a further reduction in steering ratio a model-T Ford epicycle reduction box is incorporated in the steering column, modified and now contained in a newly-fabricated steel box.
At the rear Alta-type independent suspension is used, swinging arms running forward from the rear chassis cross-member to carry the wheels and being attached to torsion bars within that cross-member. The final-drive casing is carried on the chassis and universally-jointed driving shafts on each side of it take the drive to the wheels.
Ingenuity is found in the braking system, and still more so when you examine the transmission. Taking the brakes first, those at the front came from a 1935 Riley "Merlin Nine," but the Girling operation has been changed to Lockheed. The drums are cast-iron — "We can't afford light-alloy," laughed the Emerys. At the back similar brakes are employed, but the operating cylinders are carried externally, at the top of the back-plates, to keep them cool and there is a mechanical link-up with the handbrake lever, which lies horizontally on the driver's right. A very clever feature of the rear brakes is that the back-plates are floating, being free to turn on a fibre bush, but are anchored to the chassis by the arms of the Luvax shock-absorbers. This ensures that the back-plates remain in a constant position as the wheels rise and fall and obviates that variation in braking effect normally experienced due to the action followed by this form of independent suspension.
The shock-absorbers are mounted by the rear cross-member, the arms running forward to the base of the back-plates. The transmission arrangements leave one quite breathless! The gearbox is a Type 75 4-speed E.N.V. pre-selector, with Ferodo-lined bands, controlled by a lever on the steering column, situated by the driver's left hand. The propellor shaft runs beneath the seat, the drive being stepped to the final-drive unit through an auxiliary gearbox. This second box gives 2 speeds, either of which can be selected by a small gearlever in the cockpit, although usually these ratios are not changed during a race — actually, if this box is used, eight forward speeds are available; it also gives a neutral for towing. The casing of this 2-speed box was fabricated from electrically-welded sheet metal by Emery pere. The final-drive ratio is 4.66 to 1 and in conjunction with the 2-speed box, overall top-gear ratios of 4.08 to 1 or 5.3 to 1 are available. The differential unit is E.N.V. and a self-locking device is incorporated. As mentioned the final-drive unit is mounted on the frame and the drive taken to the wheels through short shafts with Hardy-Spicer joints. The normal tyre sizes are 6.50 ins. by 16 ins, rear, and 5.25 ins. by 16 ins, front, to Riley hubs, but 17-in. tyres were used in the Isle of Man.
The radiator is one taken from a Jeep and suitably cut-down, and the tail of the body is thought to be from a M.G. Magnette, containing a 22-gallon fuel tank with two fillers. The Emeryson ran at Gransden sans body, because no coachbuilder could be found who would make one. Before the B.R.D.C. race Paul Emery got busy and in a week had made an excellent single-seater body and radiator cowling of modern Grand Prix conception. It is of light-alloy sheet with an Alclad centre-section, but light-alloy is likely to be used in entirety at some future date. The layout of the cockpit is conventional, with clutch pedal to the left of the gearbox, accelerator and brake pedals on the right. The facia carries the usual gauges and a Speedometer Supply Co. rev.-counter reading to 6,000 r.p.m. By the gearlever there is an ignition advance and retard control to ease matters when starting up.
The Emeryson had not been weighed at the time of our interview, but it is estimated to weigh in the region of 12 cwt. — possibly a little heavy, confess the cheery Emerys, for the torsion bars at present supporting the rear of the car.
Not only was it successful to the extent of winning its very first race, but it is exceptionally fast. At Gransden it was attaining 136 m.p.h. at 6,200 r.p.m. along the straights and since then the power output has been slightly increased! "So it should," is the Emery creed, Emery senior reminding us that in 1921 at Brooklands A.C.s were comfortably exceeding 100 m.p.h. on about 45 b.h.p. — he estimates the output of his modified Rapier as about 150 b.h.p. Almost as amazing as the performance of this remarkable two-stage eleven-hundred is the speed at which it was built, quite without the backing of even a small workshop. It was evolved, in the form of a rough sketch, last September, and construction did not commence until Christmas, 1946. In single-blower form the car was taken to Prescott for the May Meeting this year, but was not sufficiently completed to run. It then took our breath away at Gransden, but suffered a sheared driving-shaft universal in the second lap of the Gransden Trophy race. It was scheduled to run in the B.R.D.C. Handicap Race in the Isle of Man shortly after we inspected it. Certainly we shall watch its future career with interest, for it is one of the most effective "Specials" devised for a long while. But the Emerys are ambitious folk — even as they strive to perfect this astonishingly satisfactory little car, they talk of an air-cooled flat-twelve with hydraulically-actuated valves and something very special in the way of boosting, to be built "if ever the finance becomes available."