The first published description of Sydney Allard's new air-cooled V8 sprint car, which is competing for the British Hill-Climb Championship.
One of the sensations of this year's sprint events has been the debut of S. H. Allard's new sprint car, his air-cooled V8 single-seater Steyr-Allard. Allard commenced Motoring fast many years ago with a Morgan 3-wheeler and later with a very ingenious four-wheeler conversion of that car. His subsequent highly successful and at times hectic career with the white T.T. Ford V8 and Allard cars, is well known to all followers of the Sport. Last season Allard built a special 2-seater sprint car and experimented with an o.h.-exhaust valve head to obviate the overheating to which Ford V8 engines are so prone at prolonged full-throttle. That car went very well indeed, but someone had brought to "S. H.'s" notice a certain German air-cooled V8 lorry engine of the same capacity as a V8 Ford, but some 100 lb. lighter and giving rather more b.h.p.-91 at 3,600 r.p.m. Allard did not rest until he had acquired one of those engines and a reasonable stock of spares. Then, employing his own team of selected mechanics and working after business hours himself, he commenced construction of the Steyr-Allard single-seater sprint car, which made its debut at Prescott last May and established f.t.d. in 47.25 sec., beating Abecassis' Bugaitti. The car has been built as a private venture, quite independent of Adlards Motors, Ltd. and the Allard Motor Co., Ltd., of both of which S. H. Allard is a director. Since its sensational debut at the first Prescott. meeting, it has made 6th fastest time, tying with Mrs. Darbieshire's Riley, at Bo'ness, finished 2nd in its class and made 10th fastest time at Shelsley Walsh, and tied for 2nd fastest time with Ansell's E.R.A. to win its class at the B.O.C. Club Prescott meeting, when Gerard's E.R.A. made fastest time. Being a sprint car pure and simple it did not run at Gransden.
So well has this new Allard performed while still largely experimental, and so interesting is it technically, that we invited ourselves to inspect it and were privileged to do so when it was stripped down in the racing workshops beneath Allard Motors' Clapham Road showrooms, preparatory to the July Prescott and Bouley Bay hill-climbs.
The engine is, as we have said, a normal Steyr lorry engine, as used in German transports during the war. In a lorry it is fan-cooled through an elaborate ducting system, but Allard has dispensed with all that, trusting the alloy heads and well-finned cylinder barrels to keep cool enough for those brief periods during which the car is extended. The cast-iron crankcase has been mounted in the narrow chassis on two girder-brackets, one each side at the front, and on an alloy bell-housing at the rear, giving 3-point mounting. The cylinders are separate barrels, inclined in V-formation to constitute a 60 degree V8. Each cylinder head is a separate well-finned light-alloy casting carrying two inclined KE965 valves, the inlet valve having a diameter of 1 1/4 in., the exhaust valve a diameter of 1 3/8 in., and both valves seating on steel inserts. The crankshaft runs in five plain bearings of the thin-shell variety and there are two connecting rods per crankpin. Above it is the chain-driven camshaft, which is thus enabled to actuate the valves via simple short push-rods and the usual rockers. Cast-alloy covers hide the valve gear and each valve has two springs. Originally coil ignition was used, with the distributor set vertically above the engine, but this drive is now used for the rev.-counter and an 8-cylinder Scintilla "Vertex" magneto is driven-direct from the nose of the camshaft, it being mounted horizontal thereto. The ignition leads protrude from the bonnet sides and are led backwards through tubes above the outer valve covers, these tubes being concealed by streamline fairings when the bonnet is in place. The sump holds two gallons of oil, which is circulated by a gear-type pump driven from an extension of what was the distributor-drive shaft. One Amal carburetter is used per cylinder, mounted so that all eight are inside the V formed by the cylinders. Flanges, four each side, bolted beside the leading edge of each of the inner valve covers, form bearings for long rods which operate the throttle slides. A separate exhaust pipe runs vertically downwards from each exhaust port and these pipes are united by a horizontal, flexible-pipe exhaust system on each side of the car, which gives a distinctly, "V8" exhaust beat. An improved layout of piping is now in hand.
This Steyr engine has the usefully short stroke of 92 mm., compared with 95.25 mm. of the Ford V8 "30," and, with a bore of 79 mm., its capacity is 3,600 c.c. Not only was this unit some 100 lb. lighter than the Ford to commence with, but, naturally the fact that no radiator or coolant is required further reduces the weight of any car in which it is used. The main reason for its adoption, however, is the very good power-output which it gives low down the speed range. Something like 80 b.h.p. is developed at 2,000 r.p.m. and Allard thus finds he can let in the clutch at this speed and accelerate hard with little or no wheelspin, whereas with most racing cars the engine speed at which the car is taken off has to be far higher and the throttle has then to be eased as the car moves off to control wheel-spin. So far as maximum power is concerned, after special Martlet pistons, with slight cut-aways in the crown to clear the valves, had been acquired from the Brooklands Eng. Co., Ltd., the compression ratio went up to 12 to 1, and it is estimated that the b.h.p. is now between 140 and 150 at 4,000 r.p.m. The engine is started on benzole by pushing the car, as hand-cranking is impractical, and is then run on methanol-base J.A.P. fuel. No trouble has been experienced with the Lodge R49 plugs.
Turning to the car in which this interesting engine is installed, light weight was the obvious criterion and Allard is to be congratulated on having kept the weight of the complete car down to just under 13 cwt. This is an astonishing figure for a 3.8-litre car built, as we shall see, largely of standard Allard components.
The chassis side-members are those used for the "Competition" model Allard, united by the standard Allard girder cross-member, which carries the i.f.s., at the front, and thereafter by a substantial tubular cross-member ahead of the engine and two more of these tubular members aft. Front suspension is by the normal Allard divided front axle and transverse leaf spring, the axle having a track of 4 ft. 4 in. The rear suspension is most ingeniously simple, for a normal Allard rear axle, giving a slight crab-track of 4 ft. 2 in. with single rear wheels, is merely separated from the frame by a single Terry coil spring on each side. These springs are positioned in cup abutments on axle and chassis, respectively, and the axle is located by a ball mounted on the differential case, sliding in a guide on the chassis crossmember. Hartford double-arm friction shock-absorbers are used front and back and normally the suspension is used quite soft, in the modern manner. The steering column extends from the spring steering wheel right along above the engine to the nose of the car, where it terminates in a small rubber universal-joint coupling, which actuates a cut-down Allard-Merles steering box with the extended drop-arm shaft vertical, mounted on a bracket which is welded to the chassis frame. A divided track-rod connects with the steering arm.
The clutch is normal Ford and has stood up extremely well. The gearbox, in unit with the engine, is, again, standard Allard-Ford, giving ratios of 12 to 1, 6.5 to 1, and 4.1 to 1 with a 4.11 to 1 rear axle. These ratios are used for Prescott and it is both interesting and significant that "S. H." starts in 2nd gear — in fact, he has never yet used the lowest ratio. Second is held all the way up Prescott, yet something approaching 80 m.p.h. is reached before cutting for the first corner. Naturally, Bo'ness permitted a change into top, and about 100 m.p.h. over the line. If required, axle ratios of 3.5 to 1, or 4.55 to 1 can be substituted for the 4.11 to 1 axle, and with the former alternative the second-gear ratio then becomes 5.6 to 1. This is with twin 5.00 in. by 18 in. rear tyres, although 6.50 in. by 16 in. single rear tyres are another possibility. The gearbox is the side-control type and a short gear-lever, emerging through the r.h. side of the.cockpit, now links directly to this control via a long rod and gives very positive, if rather tricky, gear selection. Formerly a steering-column gear lever location was employed, but Allard knocked the lever into neutral at Bo'ness on one run and now prefers the more-positive normally-placed control. The rear-tyre size has already been given, and it may be remarked that Ford pressed steel wheels are used, those carrying the twin rear tyres being a clever job of welding together two standard rims. The front tyre size is 5.51) hy 16 in.
The brakes are Lockheed hydraulic and two brake pedals are used, the additional one being to the left of the clutch pedal and used to steady the car while the throttle is still being operated. An external hand-lever operates on the rear wheels only. The body is a light alloy shell of very pleasing aspect, made for Allard by Woodward of Putney. The long bonnet is no more than a detachable cover over the engine and the narrow front grille is of Allard formation. Taking a page from Alfa-Romeo's book, the facia carries a minimum of instruments — a Smith's rev.-counter (replacing a former, inaccurate instrument), an aircraft air-pressure gauge and tiny ignition switch. The fuel tank lives in the tail and has a capacity of 2 to 3 gallons, but normally only a gallon is carried. The driver's seat is a metal bucket. That then, is the Steyr-Allard, one of 1947's most interesting and successful sprint cars. It is no secret that some trouble has been experienced, chiefly from stretched valves, but Allard and his racing staff are rapidly becoming acquainted with the temperament of the specialised Steyr engine and we are indebted to them for letting us examine what is likely to become one of the fastest sprint cars in this country.
Beside the Steyr-Allard at the time of our visit stood Sydney Allard's latest road-equipped Allard, which ran in a sports-car race at Gransden, for which it was finished only at the very last minute. This is a most intriguing car. Its dimensions are the same as those of the "Competition"-model Allard, which was recently withdrawn from the production range because these cars offer comparatively cramped accommodation, and are so little lighter than the normal 8 ft. 10 in.-wheelbase cars that there was no point in retaining them in production. They are, of course, still used most effectively in competition, notably by Imhof, Burgess and Appleton. Allard's latest sports car is like one of these, but has a low light-shell 2-seater body, its side panels merging into the centre of light rear mudguards, to give a very wide cockpit. At Gransden the o.h. exhaust heads were used, in an attempt to make the engine last the 5 laps, which was unsuccessful, as the gaskets protested, but this typically "S. H." sports Allard is likely to be run in future with a normal Mercury V8 engine. As it weighs in the region of 18 1/2 cwt., it should be well worth seeing. In conclusion, plenty of production-model Allards and Allard chassis are on view at the new Clapham Road showrooms (by Clapham North Underground Station) if you are interested in one of Britain's most potent and practical high-performance cars. — W. B.