AT OLYMPIA

Wanganui Chronicle, Volume 71, Issue 261, 3 November 1928, Page 6

AT OLYMPIA

ANNUAL MOTOR EXHIBITION NUMEROUS NOVELTIES ON VIEW About this time of the year, that is within a few weeks of the opening of the annual motor ear exhibition at Olympia, writes Edwin Campbell, the press becomes interested in tLc announcements of people who profess to have solved oue of the various problems which have eluded motoring investigators ever since the niotor ear was first constructed. At one time it was substitute fuels, which promised to make us independent of petrol and its importers, but of late years revolutionary mechanical devices have been more in favour, ami, of course, that hardy annual, the £lOO motor car, is still a good suite to play. Despite recurrent disappointments, a considerable section of the public apparently still believe that ouly the greed of motor car manufacturers keeps prices above that level. At the moment of writing, 1 have not heard of any announcement concerning a fresh motor car selling at £lOO, but I shall be disappointed if the show opens without some description of the attractions of a car that is going to be manufactured for next year’s market at. that price. I will launch a 5 p.h. car in time for the Olympia, excitement, and quite possibly it will be priced at £lOO. Those who like to can buy 5 p.h. motor cars. We have had such things in the past, but, no matter how efficient they may be, it is not possible at the present time to produce a satisfactory motor car with an engine of such limited capacity. The Automatic Gear

lu all probability the star turns in the general press tuis Olympiatide will be me Robertson automatic variable gear and the coming of the Diesel engined motor car. Both of these devices are quite practical and have readied a stage wherein they may be commercialised. But it is necessary to warn those who, conceivably, believe that such innovations can be incorporated and standardised almost immediately, that there is no possibility of such occurring in time . jr next year’s trade. The automatically controlled variable gear, 1 venture to suggest, has more than a year ’s probation co encounter, while the Diesel engined car .s almost as far in the future as ever it was, despite the fact that it ha« oeen proved a practical power unit for heavy motor vehicles. 1 do not for a moment dispute tiia validity of the road tests that both 'levices have survived, but experience

Ims disclosed the wide difference between such tests in hands of expert demonstrators and the rough and ti-.uble of misuse in the hands of the inexpert, the brutal, and the careless driver. There is little or no commer- | rial future before any motoring invention or deevlopment that cannot withi stand misuse and mishandling; the j automatic variable gear, therefore, ai- ■ though it may justify every claim made for it has to demonstrate its foolproofness. Its inherent attractions are so great that one hopes fervently that it will do so- None will deny that the orthodox gear lever is the greatest difficulty of the motorist. Posuably no more than ten per cent, of us ever become really expert in its use, and even those would not grieve if the need for its existence were removed. That is what the inventor of the Robertson gear claims to ’ -.ve done, and it has to be admitted that his demonstrations prove that it enables the driver to do with the throttle conrol alone all that in the orthodox car demands the expert use of gear lever, i spark control, and throttle combined. The speed of the engine automatically controls the ratio between its revolutions and those of the propeller shaft. This is done by means of a centrifugal typo of governor gear in the fly wheel, but as to the details of the transmission system itself 1 have no particulars. I understand that it consists of an infinitely variable gear allied to a free wheel device, so that the simple act of opening or closing the throttle decides the speed of the car. As the engine is given more throttle, the crankshaft speed rises or falls, the automatic governor gear selects the gear ratio to suit and the presence of the free wheel clutch permits the engine to be cut off from the transmission for “coasting.” To Prove Its Worth The chief bugbear of automaticity in engine control is automaticity, so to speak. That is to say, there is no method of cutting out or into the sequence of operations. Hitherto acceleration with it has been sluggish, and driving under difficult, conditions, demanding rapid gear, throttle, and spark manipulations, has been made more difficult than with the ordinary gear and engine controls. This does not seem to be a characteristic of the Robertson gear, which provides as high acceleration as can ordinarily be obtained with the engine employed, and as it is said to be reasonable in its cost of production it appears to be what most of the motoring world has been waiting for. All that now remains to be done is to prove its ability to withstand misuse; that it can be produced 'and sold under commercial conditions; and that it has no inherent drawbacks which counterbalance its merits. I am afraid that the Adoption of the free wheel gear clutch by several British manufacturers will not make, the path of automatic engine control inventors more attractive. There is no doubt that with such a cluck interposed between gear box and rear axle transmission, tl technique of gear changing has been simplified and made more certain and noiseless for the duffer —and we will give it a great advantage in popularity, even with an automatic gear control that is* perfect in its operaion and behaviour, because such things are. never cheap to produce and arc bags of mystery to the vast majority, who fear mystery even more than they dislike trouble. The Diesel Engine The Diesel engine as applied to heavy motor vehicles is under test by the R.A.C., 1 believe, and doubtless the issue of the resultant certificate will coincide with public interest in the motor car show. 1 have no doubt whatever that it will come through its test quite satisfactorily. Actually this typo has been on the market in Germany for more than a year and as it issues from the Mercedes-Benz factory wo may confidently expect that it has been thoroughly tested before being launched on the public. As my readers will know, the Diesel engine consumesi:

crude mineral oil —the raw material from which petrol is abstracted and most of our lubricating oil obtained. The oil is injected under pressure into the combustion chamber in which extremely high compression—about 500 lbs to the square inch creating a temperature of nearly 1,000 degrees Fahr.— vaporises and eventually explodes the mixture. Its attractions for the motor user are cheapness in running—its fuel costs no more than fivepence a gallon—and its ability to run for considerable lengths of time without overhaul. But its drawbacks arc weight per unit of horse power, and the difficulty of disposing of its units in a manner harmonising with the demands of the body maker and the motorist. In time, no doubt, both handicaps will be overcome, but at the moment, it is essential to emphasise the fact that it is a heavy commercial vehicle proposition, and, even at that, has to demonstrate its equality with the petrol engine for bus and charabanc purposes. How long it may be before we shall see a Diesel engined motor car depends more on the makers of the petrol motor than on the Diesel engineer, 1 am inclined to think.