MOTORS & MOTORING

Dominion, Volume 9, Issue 2605, 29 October 1915, Page 9

MOTORS & MOTORING

4 [By Clutch.]

Abolishing the Magneto. Ever since tlie outbreak of -war there have been .reports from time to timo as to the difficulty in obtaining. high-ten-sion magnetos for ignition purposes. There is no doubt that this want is vory difficult to fill at present, and anything in the. nature of an alternative will therefore rcceive careful consideration from the manufacturers. On several occasions it lias been pointed out that it appears somewhat unnecessary to have a separate electrical machine for ignition' purposes when the modern car is already provided with an electrical generating machine in the form of a lighting dynamo. There is no reason why current from the accumulators should not also be used for ignition purposes as well as for starting and lighting. Quite recently there was exhibited in London a 20.1 h.p. chassis, fitted with a novel ignition system. Closer examination revealed the" fact that no magneto was fitted to the car, and that the battery current was made use of for ignition purposes. Thi3 development is extremoly striking in that a' European car manufacturer exhibiting the innovation has, at any rate, experimented with alternative forms of the ignition to the magneto. The system employed on this chassis was exceptionally compact. Occupying the usual position of the magneto is a lighting dynamo, combined with which is a low-tension contact breaker, and a high-tension distributor. The generator produces a six-volt current,: which passes via an ammeter to a set of batteries carried on the footboard. The current for ignition is drawn thence, and is passed to a plain coil mounted on the dashboard, whence the high-tension current is led to the The combined generator and igniter is not much lai'ger than the ordinary magneto, and the contact breaker and distributor (which form one unit) are mounted in a most accessible position. In the same system is included a gear driven starter, the batterios also supplying current for this. A particularly simple yet efficient device is employed for feeding the small pinion up to the gear ring on tho flywheel, and the interposition of a spring permits the starting motor to take up the drive without shock. The generator commences to charge the batteries at about 200 r.p.m., and at 17$ m.p.h. tho generator is giving its full charge of 12 amperes to the batteries, a charge which is never exceeded, liowevor high the speed of the engine. This is secured by a balance winding on the generator. As there is a distinct possibility that other manufacturers will experiment with some form of modern Jjattory ignition, this chassis is of particular interest. From a short demonstration given in the'showroom it appeared that both the •starter and the igniter functioned excellently. In view of the progress ,being made in the dynamo-coil system of ignition in the United States, the application of it to a European car is a striking departure, as it was always considered that the magneto was too firmly established to be challenged.

A Handy Motor-Cycle. 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 bo converted into a motor-cycle for about eight guineas. The motor can bo fixed to the machine in ten minutes, and as it only weighs 161b. 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. On steop hills a little assistance might be required from tho 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 bo able to understand it in a few minutes, and, of course,there would bo no difficulty in driving it. The sensation would merely be that of continually fast wheeling. The motor is attached to a carrier suspended over the back wheel. The rim is fixed to tho spokes of the back wheel, and a friction wheel driven by the motor en--gages 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.

Side-Car Driving. With the evolution of tile single gear motor-cycle to the heavy threespeed side-car machine, has come certain difficulties and complications in the art 9f driving. With the previous maqliine, when a hill was encountered the throttle was opened wide, and, beyond a certain abount of juggling with the throttle and air-levers and ignition control, the motor-cyclist could only trust that the machine would be able to surmount most 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 going on top gear as long as possible, owing to the fact that the speed when 011 low gear falls off so greatly. With a three-speed gearbox, however, an entirely new set of complications arises, and to got the best results out of a machine, and especially a heavy side-car, the outfit must be driven, moro or less, as one drives a car.

In gear-cTianging, one should not hold on to fcho top gear too long, or in other words until the speed has become very low. The middle gear has then to be requisitioned l , with the outfit hardly _ moving, and consequently the reduction to middle gear is. not great enough to allow the engine to pull the machine up the gradient. The Ipw gear has then to be engaged far earlier than is really necessary. Gearchanging; is considerably simplified for the beginner when a speedometer is fitted. On many machines it will be found that a, speed of 25 to 30 miles per hour can be attained 011 middle gear without the engines racing or vibrating unduly. It stands to reason,' therefore, that, . when on a gradient, with top gear engaged,, thero is no necessity to allow the machine to labour on this ratio, when, by changing down, the same speed can be attained. . Almost the same argument applies to the low gears, although not exactly the same, owing to the fact that low gear 18 . "h ( ' ea ' lower in relation to the middle gear than the middle is to the top. Here antf There. Legal lighting up time for motorcars and motor-cycles:—To-day, 6.40 p.rn Next Friday, 6.49 p.m. When rubber is wet. it will cut much inor© easily than when it is dry. For this reason fast travel over rough road surfaces, such as broken stone, will be more destructive to tires when they are wet. It requires almost twice the amount of;petrol to wind around in congested streets -as to run straigjit on free roads. Closing the throttle during the greater part of a hill descent will not only bo safer, hut will save petrol; Tho throttle lever 011 the steering wheel is more economical of fuel than the foot accelerator. A piece of grey cambric fastened to the top of the seat back, and sloping down to the front edge of the seat cushion, will protect the rear cushion from dust and dirt. It must bo fastened in place. Outs and gouges of casing treadß

should be repaired when the ear comes iu at night so as to allow a few hours for tho repair material to become tough. The cavity should bo well cleaned by ssraping and washing with petrol, and after allowing the rubber cement to become dry the rubber dough should ho well worked in, and the wheel turned so that the weight of the car will rest upon the repaired part during the night hours.

Many taxicahs in London are shod with a steel-studded tiro on one hack wheel, and a plain rubber one on tho other. It is claimed that the arrangement is a good one, as one cf the two tires will take a grip on almost any surface, whereas if both are steel-studded or both all rubber, surfaces are encountered sometimes which are unsuitable for the tires to grip. It is a disadvantage of t'lio combination plan that the wear on both tires is somewhat increased, one or other of them being liablo to bo dragged at times," but the additional wear and tear is not serious, provided the car is not driven at furious speed. There is no mine strain on the back axle so long as tho two tires are approximately of tho same diameter, which is the case with studded and grooved tires of the same nominal dimensions.

Touching the respective merits of detachable rims and detachable wheels, a motorist states that he has given the palm to the latter, since a car slid gently into his back wheel; damaging the wheel and rim so badly that the airtube was exposed. As the car was fitted with detachable wheels,' the accident caused no hindrance, whereas the detachable rim enthusiast would have been held up altogether. Another advantage of some types of detachable wheel is that the wheel can be turned round, and the tire caused to run in the opposite direction. This sometimes prolongs the lifo of a tire.