LAND SPEED RECORD.

New Zealand Herald, Volume LXVIII, Issue 20766, 8 January 1931, Page 14

LAND SPEED RECORD.

"WIZARD" SMITH'S ATTEMPT

CAR NEARING COMPLETION.

Rapid progress is being made in the construction of the car in which Norman "Wizard" Smith will attack the world's land speed record at the Ninety Mile Beach, North Auckland, early in March. Th© car is being built at tho works of Harkness and Hillier, Limited, of Sydney, and the work is proceeding in tho greatest secrecy.

Tho Napier engino, obtained on loan from the British Government, is a secret of the British Air Ministry, and Mr. Norman Smith is pledged not 'to divulge any of tho details of design. Meticulous care has beon taken in the streamlining of the engine. All accessories such as magnetos and water pumps, aro shielded behind the cylinders, to prevent the creation of wind resistance. When the engine is placed in position in the chassis, the 'top surface of the valve mechanism cover plates of each bank of the "Broad Arrow'* formation will be opened to the air to secure adequate cooling. Air for the carburetters will be forced by the velocity of the* car through louvres, provided in the front of tho chassis fairing, and in the fairing for tho cylinders. A supercharger is provided in tho induction system to ensure complete filling of the cylinders with a mixture of petrol and air at a pressure above atmospheric pressure. The speed of this engino is, incidentally, approximately double that of the normal type of aero engine. During the preliminary trials of the car and for 'tfho starting of the engine for the attempt'on tho world's record', a special single-cylinder engine will bo mounted on the .running board of a fast car. Gear-box and Transmission.

The gear-box is constructed as lightly as possible, consistent with strength and stiffness, and the well-known anti-friction properties of ball bearings aro being utilised by the fitting of this type throughout the unit. Provision is made for three forward speeds, but no reverse gear is fitted, v The forward speed gears havo been designed with ratios to give 100 m.p.h. in first gear, 200 m.p.h. in second gear, and 300 m.p.h. iti third gear. Theie is a single drive to the front of the gearbox, but at the rear of the box the drive is split, being taken by two parallel propeller shafts provided with metal type enclosed universal joints at each end. These drive shafts are.enclosed in armourplated tunnels of metal one-quarter of an inch thick to protect the driver, who sits between them, in case of failure of one "or both of the shafts. The differential incorporated in the rear axle of the normal motor-car does not oxist in the "Fred. H, Stewart Special. The final drive to the rear wheels is by means of a crown wheel and pinion attached to the drive shaft. A double clutch is being provided to transmit the power from tha .engine, consisting essentially of a friction clutch which will be capable of transmitting up to 400 h.p-,

while the machine is gathering speed and positive driving dogs, which will be engaged for the higher speeds. This type of drive has, of course, been adopted to re. duce to zero the possibility of clutch slip and possible seizure with disastrous results to car and driver. The Wheels and Steering-gear. Specially-built tyres capable of running at, a speed of 310 miles per hour, inflated to a pressure of 1401b. per square inch, are being provided- The rubber of the tread is only one sixty-fourth of an inch thick, and with the rubber between the 12 plies of cotton cords is specially com* pounded to avoid overheating. It may be wondered why 12 plies are necessary for this tyre, but it should be noted that at a speed of 240 m.p.h. (sufficient to beat the present record handsomely) the centrifugal force tending to disintegrate the tyre amounts to 15601b- per ounce of the tyre periphery. The spokes will bo streamlined by solid steel discs to decrease wind resistance. The streamlining of tha rear wheels will bo cared for by tho two stabilising fins at 'the rear of the car, but as the surface radiators employed pn the "Golden Arrow" *ra not being used on the "Fred. 11. Stewart Special/' the actual details of tho streamlining of the front wheels have not been finally de--01 The steering-gear of a car designed to traverse one-twelfth of a mile in a second necessarily must be conceived and com structed with the utmost care and precision. The lay-out decided upoii consists of direct coupling to each of the front wheels per medium of drag links and steering arms from a specially-designed steering-box located behind the engine. In addition, the two front wheels are coupled by a track rod in case of failure of the independent Steering. Tho steering column and wheel are horizontally disposed. the wheel having a diameter of 16in. Worm and wheel steering has been adopted. THE HOWIGK ROAD. The opening of the concrete highway to Howiek will popularise the seaside beaches in this district, and will enable motorists to make tho journey to the various beaches in much shorter time. It must not be thought, however, that causo there is a concrete road this can be converted into a speedway. The Aueklartd Automobile Association _ suggests that motorists exercise a certain restraint and at &H times observe the policy of "safety v first." It has been noticed by close observers that surveyors have been busy on odd sections of the road, and from little white pegs' that have been driven, the impression has been gained that there may be more than One qnarter?niile stretch prepared over which stop,watches might at tjmes bp operated.