BUILT FOR BROOKLANDS AND MONTLHERY.
BUILT FOR BROOKLANDS AND MONTLHERY.
THE NAPIER-RAILTON PASSES ITS FIRST TESTS IN THE HANDS OF JOHN COBB.
After many months of hard work by all those concerned with the project, the new 12 cylinder Napier-Railton car has at last reached the stage of completion, and was formally ” launched ” on the Tuesday following Whit-Monday at the Brooklands premises of its constructors, Messrs. Thomsson & Taylor, Ltd.
The first point which strikes one on considering the specification of the car is the absence of any remarkable departure from orthodox practice. Rather has the aim of its designers been to build a car on well-tried and therefore reliable lines, which will be sufficiently powerful to run well within its limits even while records are being taken. Thus, although the maximum speed of the car will be in the region of 170 m.p.h., the scheduled average for the forthcoming 24 hour record attempt at Montlhery will be 120 m.p.h. including pit stops for refuelling and changes of drivers and tyres. The engine is a 500 h.p. Napier Lion aero unit, modified for ground work, and the power reserve is indicated by the fact that 120 m.p.h. only requires 250 h.p. from the engine. The oil and fuel tanks only contain sufficient supplies for 21 hours running—the limit of the car’s
tyre-wearing capacity. For the fuel a constant delivery fuel pump is fitted, while there are two oil pumps, one to feed the bearings and the other a scavenger. The engine can be started by hand with the assistance of a hand starting magneto.
A normal single-plate clutch is used, and the 3 speed gear box has been kept compact by means of very high tooth pressures and a very strong tooth forma design only possible where the gears are used solely for getting away. The propellor shaft has universals at both ends and the forward joint allows for sliding. The rear axle body is composed of three machined high tensile steel forgings, and the axle ratio is 1.66 to I. Beneath. the casing an elektron oil sump prevents the possibility of inadequate lubrication. Rear-wheel brakes only are used, operated by cam and rod. The suspension has been specially designed to meet track conditions, which differ very considerably from those met with in road-racing. The Napier-Railton has four cantilever springs at the rear, two on each side. By hinging the axle at the rear ends of these springs the latter are made to take all the braking and driving stresses—besides reducing the stresses in the axle casing, easing the work
ing conditions of the universals and maintaining the axle position in the event of a broken leaf. The front springs are normal half elliptics shackled at the front end, and the system is strengthened by means of short radius rods. Four shock absorbers are fitted to each axle, two being of fixed setting, and two of the hydraulically operated remote control type.
A tubular front axle, built up in three pieces, is used and the steering layout is. of normal design of worm and wheel. The frame is underslung at both ends, and is. strongly braced by tubular cross-members.
For night driving during long-distance record attempts the car will be equipped with a dynamo, belt-driven off the clutch shaft, a battery and two large headlights.
The car was demonstrated to a gathering of friends last month, and John Cobb announced that it handled perfectly and was all ready for its first public appearance at Brooklands on August Bank Holiday.
In appearance the body is not unlike that of the old :Delage, with a fairly short tapered tail and a striking frontal aspect given by the curved strengthening rib in front of the radiator. The seat cushion and squb are each about 12 inches deep, and with the controls all within reach the driver should have a comfortable ride. Three silencers are fitted, one for each bout of cylinders, and the car is surprisingly quiet.
On a fast and very powerful car such as the Napier-Railton tyres always constitute a great problem. The Dunlop Company as usual were equal to this and produced for the back 35 by 6 inch smooth covers of unusual tread width, while a slightly grooved pattern is used in the front in order to lessen the effort of steering.
Cobb put in some demonstration laps at 130 m.p.h., so the lap record ought to be raised on the Bank Holiday if the track is dry. In short events of course getting away from a standstill will present some difficulty, for even with the lightest throttle manipulation, long black streaks of rubber were left on the concrete.
Harcourt Wood, Cobb’s fellow driver at Montlhdry also tried out the car. It will probably go to Montlhery as soon as there is a full moon and we understand that the track is to be floodlit. We wish the drivers the best of luck in their attempt to capture for Britain the muchdesired 24 hour record.