MOTOR AND CYCLE

Taranaki Daily News, 23 October 1915, Page 11 (Supplement)

MOTOR AND CYCLE

2JEWS AND NOTEa I The substitution of motor fire engines in the Commonwealth capials for tlie oldtime horde-drawn vehicles has been gradual, hut sure, and to-day the major part of the fire-fighting plaut is petrol-driven. In Melbourne alone the approximate value of the motor engines, etc., is £2G,000, and similar large amounts have been expended throughout the Commonwealth in modernising the fire brigades. » * c The amateur road championship of Victoria wa9 decided over a 25 miles road course oa September 9, and resulted in a splendid contest. The field had been previously reduced by qualifying events to six riders, and these comprised the field for the final. The winner proved to be J. fP. O'Fairell, who won by half a wheel from L. Jenkins, with T. O'Farrell a length back third. The time was 1 hour 14 minutes 15 seconds.

An attempt to establish a motor-car record from Fremantle to Sydney, via Adelaide, will probably be made during the next month. The party undertaking the trip will comprise Messrs Hagh, Fraser, P. W. Armstrong and two others. The car is a 6-cylinder Studebaker, shod with Dunlop tyres. The, distance of this overland trip will approximate some .'1077 miles. The bicycle record for this journey from west to east of the continent is :ll days 3 hours 15 minutes, standing to the credit of F. Birtles.

A motor attachment that will interest every cyclist is to be placed on the English market shortly. By means of this attachment any bicycle can be converted into a motor cycle for abut 8 guineas. The motor van be fixed to the machine in 10 minutes, and as it only weighs 16 lbs. it can be disconnected at any time in the unlikely event of a breakdown, and the machine can then be pedalled home. The power is estimated at 1 h.p., but as a matter of fact, it will develop more. This means that on a level the motor will propel a machine at the rate of from 20-25 m.p.h. per hour. On steep hills ft little assistance might t>o required from the rider. It is estimated that a gallon of petrol would be sufficient to propel the machine 150 miles. The whole engine is so simple that any cyclist would be able to understand it in a few minutes, and of course there would be no difficulty in driving it. The sensation would merely be that of continually free-wheeling. The motor is attached to a carrier suspended owr the back wheel. A rim is fixed to the spokes of the back wheel, and a friction wheel driven by the motor engages with this and transmits the power. It is expected that the motor will be on the market within a few months, and it is anticipated that there will be a good demand for it.

There is one adjustment of a four-j cylinder engine which, if properly carried out, makes an enormous difference to the runnfag of the vehicle, and yet it is one wihch is to a large extent neglected by motorists, namely, the adjustment of the tappets that raise and lower the valves. Ju all modern car* the height of these tappets is adjustable, a.nd their height will determine the height to which the valve is lifted from its seat. This adjustment will not, of course, alter the maximum lift and fall, which are determined by the contour of the cam; but where the tappet does not reat-b to the valve, when the latter is on its seat, and the tappet is at the bottom of its travel, the space interval will represent a certain loss of area of opening, and in that respect the gases —ingoing or outgoing, as the case may be—will be throttled. Not only does this space between the tappet and the valve give inefficiency in that direction, but it is also obvious that the lift of the valve will he late and its drop on to the seat will be early. The combination of too late a lift, and too early a drop, with too small a rise, will multiply the error, and prevent the cylinder to which it applies giving out its full power. When this happens in one cylinder or two, or when it happens in a varying degree at all, we get unbalancing of the engine, and an inability to run steadily at low speeds; we also get considerable inefficiency. It will therefore be seen that it is of the utmost importance for the car-user himself to ascertain that the valves are lifting equally—that is to say, that the space between the top of the valve tappets and the bottom of the valve stems is equal for all the valves, and this measurement can only be ascertained when the cam has left the tappet at the bottom of its travel, and the valve is on its seat, and should be measured with a thin piece of tin or sheet metal when the engine is hot after having been run for a few minutes. The distance should be about one-sixty-fourth of an inch.

With the evolution of the simple fixedgear motor-cycle t 0 the heavy three-speed sidecar machine have come'certain difficulties and complications in the art. of driving. With the previous machine, when a hill was encountered, the throttle was opened wide, and beyond a certain amount of juggling with the throttle and air lever and ignition control, the motorcyclist could only trust that the machine would be able to surmount at least the majority of the gradient, the remainder of the climb being as often as not carried out with a panting motor-cyclist pushing alongside, The two-speed "gear, with its great reduction from top to low does not present many driving difficulties; the engine is kept on top gear for as long as possible, owing to ' the fact that the speed when on low gear falls of!' so greatly. With a three-speed gear box, however, an entirely new set of complications arises, and to get ilia nest results out of a machine, and especially a heavy side-car machine, the outfit must be driven more or less as one drives s. car. Undoubtedly the commonest mistake made in gear-changing oa a motorcycle is to hold on to the top gear too long, or, in other words, until the speed of the machine has become very low. The middle gear then has to be requisitioned with "the outfit hardly moving, and consequently the reduction to middle gear is not great enough to allow the engine to pull the outfit up the gradient, consequently the low gear has to be engaged far earlier than it is really necessary. Gear - changing is considerably simplified for the beginner when a speedometer is fitted. On many machines it will be found (hat a speed of A"> to :Sl> miles per hour can be obtained on middle gear without the engine racing or viIbrating unduly. It stands to" reason, (therefore, that when on a gradient with top-gear engaged there is'no necessity to allow the machine to labor on this ratio when by changing down the same speed can be attained. Almost exactly the same argument applies to the low gears, although this eau hardly be said to be exactly the some, owing to the fact that low gear is a good deal lower in relation to the middle gear tbaa the 1 middle is to the toy.