MOTOR AND CYCLE.

Taranaki Daily News, 26 July 1919, Page 10

MOTOR AND CYCLE.

NEWS AND NOTES,

INTERNATIONAL MOTOR SHOW, The 'groat International Motor Show at Olympia, London, which was one of the premier automobile exhibitions in the world in pre-war days, is to be revived this year, being set down for November next. It is interesting to note it has been decided that whilst the exhibition will be fully international no goods of enemy origin will bo allowed tjo bo shown. This decision is comprehensive, and means not only that no German or Austrian cars will be allowed to be exhibited, but that no tyres, parts, accessories, or fittings of any kind from enemy countries' will be permitted.

THE PETROL ENGINE. When war broke out the petrol engine was making steady, if not particularly rapid, progress, says the Scientific American. For several years attention had been directed to the improvement of details and the solution of minor problems, the general design remaining unchanged. The period of rapid progress that followed the realisa. tion, a quarter-century ago, of the possibilities of internal combustion, had passed; as an accepted power unit, the petrol engine had acquired, with its acceptance, more or less of an accepted form. Its evolution toward whatever it is ultimately to be was taking its normal, deliberate course—one which ordinarily is satisfactory enough. The war, however, brought new conditions and new demands. It brought the demand that the petrol engine he made a much better machine without waiting for the lapse of sufficient time for ,the ordinary evolutionary reactions. The immediate effect was a quickening of effort, with the determination to bring the future back to the presentto do ,to-day things that under less strenuous conditions would have been left for next year, or even for five or ten years hence.

POSSIBILITIES OF THE FUTURE. The pressure of war-time necessity has resulted in the accomplishment of much, and has started lineß of effort that are more or less certain to lead to remarkable endings. Just what has been done, just what has been started and not yet finished, we shall not know until silence has become an altogether unnecessary precaution. But if fragmentary hints are not entirely misleading, there will be revelations that will open many an eye. Some of the results are known, others are not; a grea,t deal is left to the imagination. Leaving a matter of this sort to the imagination is nothing more or less than an invitation to speculate against the future. What latent possibilities a« there in the internal combustion engine? What undesirable qualities does it possess that may perhaps be eliminated?

To-day the most conservative of engineers hesitates before using the word "impossible," even though possibility may bo utterly obscure. In the past many have used this word who were eminent men, as well,as qualified to ex. press opinions as the contemporaneous state of the engineering profession then permitted. Where they erred was in making all their calculations in the light of what they already knew, failing to take into consideration the unknown quantity of future knowledge which might—which did—entirely upset prognostications. «

There is, then, ample justification for speculating a little as to ,the future possibilities of the internal combustion engine, without gazing too intently into the undeniably bright light of existing knowledge and being blinded by it. The fact that something is utterly impossible to-day means only one thing—that we do not yet know how to accomplish it. It by no means indicates that we shall never know how to accomplish it.

THE TURBINE. The thought that turns up automatically is that of the internal combustion .turbine, But while that type of motor will doubtless come into being, without reciprocating auxiliaries or attendant drawbacks of other sorts, there is plenty of room for the imagination to play in, without going beyond the familiar reciprocating engine of to-day. In fact, it is necessary merely to take the thought of some of ,the commonplaces of engineering. For instance, when we feed to a petrol engine 100 heat units in the shape of fuel, all we get back in the form of power is the equivalent of about twen.ty-five heat units. Using easily, round numbers, it appears that something like 10 per cent of the fuel burned is used to generate the power to overcome the friction of .the moving parts; that 30 per cent is literally and intentionally thrown to the winds-=-ab. stracted from .the cylinder walls by the water jacket, carried to the radiator, and dissipated in the rush of cooling air; that 35 per cent goes' straight out through the exhaust pipe. So it'is neeessary to buy and carry around' and handle and provide space for three gallons of fuel for every gallon that does useful work. Right there is a vast field of possibilities—a field 300 per eont greater than that of actualities. If the steam engine were as prodigal of heat as is the petrol engine, it would be a hopelessly inefficient piece of apparatus. Once steam reaches the cylinders, however, it is handled with the most painstaking care so .that not a heat unit shall be lost that it is possible to save. What heat is left after the first piston has been moved is transferred to another sylinder and set to work on another piston, even unto the third and fourth expansion. When the steam is too old and feeble to push pistons i,t is suddenly condensed and made to do work on the other side of the pistons by leaving a vacuum. Finally the heat still left in the water js saved by going back into the boiler With the feed-water. Compare this with the beautifully simple process of the petrol engine. At the end of the stroke a valve opens and 35 per cent of the power that has been created is shot into the air through the exhaust pipe, while 30 per cent is blown away by another route—neither exi.t being big enough to pass all the heat that must be wasted. These things are done because we do not know any other way to avoid them. Elimination of the cooling system would allow most of the heat carried off by the cooling water to remain in the cylinders; but with existing engines the result would be merely a small increase of power for a few revolutions, followed by stoppage through over-heating. Increasing the temperature of the cylinder walls beyond a certain point first destroys the lubricating qualities of the oil; and without oil we do not at present know how to make an engine run. Even if we had an oil that ,toeul&staad all-the,h.eAt w* eouli.geat j

erate, however, we could not advance much fur.ther; for we should have excessive expansion to contend with, while the metals we use for cylinders and pistons would soon reach a temperature at which they would lose their strength and disrupt. As for ,tlie" 35 pffr cent of heat that passes out through tlie exhaust pipe in.the form of gas at high pressure, attempts have been made to utilize it by expanding the gas a second time in a largor cylinder—as is done in steamengine practice; likewise by giving the piston a variable stroke, the intake being short and the expansion stroke proportionately long to carry expansion to a comparatively low pressure. These and other expedients have been more Or i less exhaustively tried out, but they . have added so much weight and complication and noise and expense that none has ever got much, past the experimental, stage. Such, roughly, is the present , s,tate of affairs, and the problems that must be fathomed before real efficiency , is obtained from the petrol engine.

ENEMY EFFORTS. In view of the certain efforts of the enemy countries to regain some of their lost trade in .this country in the near future, an announcement in the Queensland Press, issued by the Queensland Motor Tyre Association, is mum to point, and worth quoting:— "Allied or German-made tyres. When Herr Rantzau replied ,to the Peace terms he studiedly insulted the Allies by remaining seated. Decent-minded Britishers all over the world boiled with indignation. When Australians—our sons and brothers—first appeared in the trench line of France, the Germans greeted them with placards bearing filthy insults. When Nurse Cavell was murdered, the world was struck with horror. For a month after Louvain every British bayonet sank home with the hissed reminder, 'Remember Louvain.' The Lusitania still ranks as the victim of the world's greatest murder. When over the last four years the cables told of the German cruelties .to Australian prisoners of war, Australian mothers and fathers suffered agonies in silence. Fifty-eight thousand of Australia's best gave up their lives to lay the German low—for what? Was it for Australian motorists at home promptly to raise the Hun again by helping him rebuild his industries f Every Germanmade tyre bought by Australians is an insult to the price we paid for victoryThe one .thing Germany now most desires is to recapture her lost trade. Motorists! see to it that she does not recapture her lost trade in Australia. Therefore, buy only allied tyres."

ENGLISH MOTOR CYCLES. A glance at the list of English motor cycles to be manufactured this year shows that change-speed gears of one kind or another have been almost invariably adopted. The majority of machines from 3J-h.p. upwards appear to be fitted with tliree-spoed or infinitely variable gears, whilst amopg the lighter types the two-speed clutchleßß gearbox seems very much in favor. A few small singie-gear two-strokes are standardised, but one cannot holp feeling that this is done chiefly with the intention of keeping them within the poor man's purse. There can be no doubt whatever that there is still a demand for the single-gear 3J-h.p. T.T. machine, but the majority of manufacturers are not putting one on the market. Motorcyclists demand gears and clutchesKxtra weight and price go with them; but that is only to be expected. Few motor-cyclists realise what a big increase in price of machine is incurred by the addition of a three-speed gear, and its essential fitments. One well-known firm in England charges £56 for its 4h.p. single-gear model, For the same machine with a three-speed gear the price is about £BO, This will serve to illustrate how these extras increase the price to the user. If a low-priced machine is needed, then all bucli fitments will have to be eliminated. That they are not absolutely necessary has been ' proved in the past by the fine work done by Bingle-geared motor cycles the world over.