AN INDIVIDUAL RACING CAR

AN INDIVIDUAL RACING CAR

THE APPLETON SPECIAL, ORIGINALLY DERIVED FROM MASERATI AND RILEY COMPONENTS, NOW COMPLETELY REVISED TO THE OWNER’S IDEALS, PERFORMS WITH DISTINCTION AT SHELSLEY AND BROOKLANDS

Most of us at one time or other have thought out a design for a hybrid car combining the virtues of several makes or types. If the venture ever gets beyond the paper stage, it is usually confined to some comparatively simple operation such as building another variation on the G.N. theme, or the hanging of a supercharger on some power unit which was never designed for it. Pew people have the skill or the resources to carry their ideas to the finished stage, and even when they do there is no guarantee that the car will “work.” The Appleton Special is a notable exception, having now reached the status of an individual racing car comparable to the FrazerNash” Terror,” the Villiers Supercharged, and the blown Riley now driven and owned by Mrs. Petre.

Mr. Appleton gained his first racing experience at the wheel of a four-seater Riley 9. This chassis of course was much too heavy for serious racing, but he found the 1,100 c.c. four-cylinder engine responded well to tuning. He then secured the 1,100 c.c. Maserati which Widengren drove in the 1931 Double Twelve, and discarding the eight-cylinder engine, installed in its place a racing Riley 9 unit. Twelve inches were removed from the side members of the chassis, the joints being welded and strengthened with back plates. The engine was modified by fitting a special type of bronze cylinder head.

The early trials were disappointing. In the first place the car was decidedly slow, and also, as the owner remarked, it was a little dangerous. “On corners it always wanted to go straight on, but on straights it was almost impossible to keep it on its course.” In spite of these rather serious defects, Appleton climbed SheIsley in 48s. at the May 1984 meeting and scored a second at Brooklands at the Bank Holiday meeting. A year’s work went into it before its next appearance. in supercharged form

and with a stren.gthuned chassis. At Brooklands Appleton scored another second in a mountain race, Shelsley he climbed in 44 seconds, beating Hall on the Magnette by .6 seconds, and was second in his class at the Brighton Speed Trials, averaging 68.12 m.p.h. for the standing half-mile. The two-bearing crank-shaft was the impediment to still higher powers, so during the past winter a three-bearing shaft was installed. Practising at Shelsley, the Appleton Special was amongst the three or four fastest, and even in the wet the car got up in 454 seconds, fastest in the 1,100 c.c. class. At Whitsun., Appleton won a long handicap at Brooklands, and has equalled the 1,100 c.c. Mountain Record. At Donington the (unofficial) 1,100 c.c. record also stands to his credit, a circuit with a speed of 88 m.p.h. Carburetion is still a little, tricky, and at Lewes the car refused to fire on all four, but Appleton is confident that when the benefit of the mixture

problem is solved the car will be even faster and better than at present. Now for some details of this beautifully made Special. All that remains of the Riley engine is the cylinder-block-cumcrankcase, and even this is modified. The cylinder-head is cast in aluminium bronze and was designed by A. P. Ashby, the Hendon Riley specialist. The valves are operated by very light rockers, which work on needle roller-bearings, and are so short that the springs close up solid when fully compressed, effectively preventing valve bounce. 14 ram. plugs are used inclined at an angle to the cylinder • and firing through masked openings. The supercharger is a large Zoller, chain-driven from the front of the engine and supported on a skeleton crossmember. It draws its mixture from a truly enormous S.U. carburetter, and delivers it to the engine through a short length of Clayton Still tubing, which acts as an intercooler, at a pressure of 25 lb. The compression ratio incidentally is 6f

to I. When a supercharger was first applied to the engine, trouble was experienced through the mixture piling up at the end of the induction pipe and sooting the plug in the rear cylinder, but this has now been overcome, by having an adjustable extension beyond the rear inlet branch.

Some very delicate work was needed to fit an additional bearing in the centre of the crank-case, while the construction of the crank-shaft must for the present remain a secret. We can however reveal that the centre journal is of exceptional size, so much so that it serves as the central (and sole) flywheel. The main bearing in which it rotates is faced with a special type of bearing metal to withstand the high rubbing speeds set up.

The pistons are Hepolite pot-type, with light alloy H section connecting rods. Cooling and lubrication Pare two of the greatest problems on a small racing engine. A specially made water-pump with toothed impellors feeds two-thirds of the supply to the rear of the cylinder head. The remainder goes into the exhaust side of the cylinder-block, shooting up through small holes into the head, where it impinges on the exhaust-valve se a tings.

The oil pump is mounted externally on the side of the crankshaft, and forces the oil through two cleaners and an air-cooler, a miniature radiator built up with copper tubes, to a distribution box at the front of the engine. The oil is fed to the bearings, the rocker boxes, the supercharger and other parts through external flexible pipes and as the normal oil pressure is 140 lb., there is no difficulty in detecting leaks.

With the two-bearing crank-shaft the engine developed 129 h.p. at 5,800 r.p.m. ; unfortunately no figures are available with the three-bearing crank. The latter component is warranted safe up to 13,000 r.p.m., and the connecting rods to 11,500 r.p.m., but the pistons are not yet suitable for these exalted regions. 8,000 r.p.m. is the present maximum, and at this speed everything seems quite happy.

An E.N.V. seq-changing gear-box is bolted to the back of the engine, and a long selector-lever working in a central quadrant comes up between the driver’s legs.

The back and front axles are from the original Maserati, and have cable brakes with bicycle-chain compensators, the balance between those on either side of the car being maintained by means of a miniature differential. Radius rods are fitted to the front axle.

The side-members are also Maserati, but drilled and lightened so that the famous ” Fratelli ” would certainly never recognise them. No fewer than seven cross-members are fitted, not including the light one which supports the blower. The aim has been to get the portion of the chassis from the front dumb-irons to the gear-box as rigid as possible, . with a little whip further aft to aid road holding, and particularly stout-looking braced box members are used in front and behind the engine. In spite of all this the chassis only weighs 102 lb. Weight-saving and fine workmanship are in fact the predominating features

of the chassis, the drilling and lightening of side-members and cross-members being carried out with skill and artistry. RollsRoyce light alloys are used wherever possible, and the front shock-absorbers weigh only 2,3-, lb. each. Even the pedals are made of light alloy, while the driving seat is made of riveted sheets of duralimin, following aeroplane practice. The car complete with fuel weighs just 141 cwt. Great care has been taken with the streamlining of the body, and even the filler caps are enclosed. Lids secured with spring catches give access to the plugs and the 2-gallon auxiliary oil-tank, which feeds the crank-case by means of a float-controlled needle valve. The fuel tank holds 20 gallons and has an eight-inch quick-filling cap. This is

reached by swinging aside part of the fairing behind the driver’s head. Thefuel consumption works out at 4 to 6 m.p.g. now that a fairly low back-axle ratio is fitted, 4.9 on Shelsley and 4.2 for Donington.

The car is painted dark blue and frontaxle and other chassis parts are highly polished, a turn-out which does justiceto the skilful design and beautiful finish of the parts beneath the bonnet. The total cost of the car during its 24years of development has been 0,200, which included a good deal of material made up and discarded as unsuitable. Before concluding the article mention

must be made of another Appleton production, the Appleton Riley, which was. driven by Llewellyn Appleton, R. J. W.’s. brother, at Shelsley. In the Shelsley tradition this has the front half of an A milcar chassis, welded to the rear end of a G.N., with the usual all-chain transmission. The engine is a four-cylinderRiley brought from the local scrapyard, bored out to take a racing crankshaft and with the compression raised to 14 to 1. A Singer radiator is used with a water-pump from a Standard, Austin steering and non-standard components. Pertinent figures are that the outfit weighs 8 cwt., does 99 on the road, and costs complete with trailer £60. While not attempting to compete with theSpecial, the Appleton Riley shows what can be done for a small amount by a knowledgeable owner.