MOTOR AND CYCLE.

Taranaki Daily News, 25 October 1917, Page 7

MOTOR AND CYCLE.

NOTES AND COMMENTS. There is little doubt but that aluminium is going to play a big part in the motor engine of the future. Gradually more and more of it is being utilised in the construction of the petrol engine. As evidence of what is possible in that direction, a recent performance by L. Chevrolet —an American driver who builds hia own cars —ia instructive. Chevrolet won the recent big Cincinatti motor speed event with its first prize of £-2000. The distance, 250 miles, was carved out in the very fast time of 2 hours 28 minutes 47 seconds, giving a speed average of over 102 m.p.h. The most interesting feature about this performance was that it was accomplished with a comparatively small engine, viz., 298 cubic inches and that it was practically constructed with aluminium or rather an aluminium alloy known in America, as (Lynito, which is about two thirds lighter than cast iron. In the engine in question the cylinder

block, clutch, h casing, engine base, etc., were made of this alloy. The weight of tlie engine complete was only 4901b5, whilst the complete car turned the scale at l'HOOlbs, or 3001bs less than any other car competing in the race. Chevrolet's performance demonstrated that racing cars can be built much lighter than is the custom and what is practicable on the speedway is usually later adopted to the advantage of the touring car. T"he car of the future is undoubtedly going to be considerably lighter than the present day models which means lower running cost in petrol and tyres. In view of the calling up of the-male population for military service it was only to b> expected tFat the revenue from the cycle tax in France would stiow a falling off. The maximum rev.-nue raised from the tax was in 1014, when no less than ;C444,*M) was received, which at 2s fid per machine represents over three, and a-half million cycles. In 1015 the revenue fell to £112,920, while according to figures just issued,- the revenue from this source last year was £llO,320 This decline in the use of cycles must have had a serious effect on the cycle industry in Prance. One often wonders whether throttle by foot accelerator is the ideal method. All of us who use a foot accelerator may have noticed how difficult it is to keep it anything like steady on a rough road. A series of jolts over pot-holes on a bad road causes similar jolting of the accelerator pedal. Many motorists even when driving with a hand-control, believe in moving the lever almost constantly, and there is no doubt that an engine will accelerate moro rapidly by a "jiggy" opening of the throttle. I seems to prevent the ohocking that occurrs when the throttle is opened evenly and rapidly. If this is true, there seems no reason why the involuntary movement of the foot accelerator, due to road inequalities, does any barm. From the point of view of petrol consumption, the evener and finer movement possible with a hand control tends to greater mileage. It is rather an interesting subject in these days of dear motor spirits

It is interesting to note that the bicycles used by the British authorities at tho front are fitted with free wheel hubs, "pull up" front and rear brakes, and 28in s l%in tyres.

Very few motor-cyclists pay proper attention to the lubrication of the mov-

ing parts and the various joints of the brake control rods. These require as much attention as, if not more, than the hubs of the wheels, which one sees so many people oiling in their spare moments. Others fail to realise that in tie case of a brake operating on either the inside or outside of the belt rim, the actual brake block must at the moment of application be bearing along its whole length on the belt rim. When, too, a new brake block is fitted, it should be seen that it conforms to the contour of the rim, as otherwise there will be trouble. Several manufacturers seem to omit to give any adjustment in order to correct the position of the brake block and bring it to its proper position; and a very large number of motor-cyclists, even when this adjustment is given them, do not know what it is for. When will both manufacturers and motor-cyclists realise that efficient brakes on their machines are more important from the point of view of the public than the engine'; If they would pay, more aUjntion to brake design adjustment there would be fewer accidents among motor-cyclists. Three of the leading car manufacturing companies in America, the Maxwell, Chevrolet and Grant have announced a considerable advance in the price of their cars.

A motor car traffic unsui was reee'.y taken at the Public Library on Fifth Avenue, New York, between H a.m. and 6 p.m. During that period 10,900 motor vehicles were counted, or an average of 2S cars a minute for the ten hours of the icheck.

Many motorists are unaware why a light piston makes for more power—hence more speed; The latest indications point to the coming of the aluminium'piston and many advantages are claimed for same. It is stated that the weight of an aluminium piston is only about one-third that of a cast iron one 01 tlyj same design; therefore the in[ertia forces attributable to the purely reciprocating mass are considerably reduced .($0 per cent., it is claimed). The specific gravity of pure aluminium when east is 2.59, when rolled 2.68. The 'specific gravity of iron is about 7.21; that of steel somewhat higher. Thus it will be seen the weight of aluminium is, for equal volumes, but slightly more than one-third that of iron. The coefficient of friction of the aluminium piston alloy is but half that of iron : hence there must be a. gain in mechanical efficiency of the engine. Piston side pressure may be increased without unfavorable results. The American Government has selected 110 mechanics from automobile factories who will be sent to France to study the manufacture of aviation engines, Of these sixty-three are from Detroit and sixteen from Indianapolis. They, will spend several months abroad and on their return will supervise airplane engine building. The United States are aiming to place 4000 airplanes on the front next spring, and it is anticipated that this will necessitate '20,000 median-. ics. These will be drawn largely from reyair shops and garages. Rapid proigress is already being made at the big '. Government aviation schools.