MOTOR AND CYCLE

Taranaki Daily News, 6 May 1926, Page 14

MOTOR AND CYCLE

MORE CYLINDERS FOR MOTORISTS ENGINES IN THE AIR. THEIR SIGNIFICANCE TO ROAD -SERVICE. (By H. Massac Buist.—Copyright.) London, March 4. In the ordinary way the user of a four-cylinder engined .popular car regards such motoring feats as the various flights across the Atlantic, or from this country to Australia, to South Africa, or elsewhere, as of picturesque interest only. I venture to suggest, however, that these things are of practical concern to him, if not at the moment, at least in the bearings they will exercise in a few years’ time on the cars he himself will be using in the most economical and satisfactory fashion. It is abundantly plain that -while 25 years ago the one-cylinder engine was manufactured in greater quantities than any other type, and 18 or 20 years ago the two-cylinder engine that superseded it was built in the greatest numbers merely because it could be made cheaper than contemporary types. So to-day, despite a long interval of time, the bulk of the world’s motor vehicles are equipped with four-cylinder engines only; witness particularly the aggregate outputs of Ford, Chevrolet, Dodge, Citroen, and Morris, to name but five of the world’s large scale builders. It is clear, however, that, save for cost, everybody who could would have a car equipped with an engine having at least six cylinders, if not eight, or more, would gladly possess -himself of one. Indeed, to-day the majority of motor vehicle users look at one almost incredulously when one recalls that, on the advent of the six-cylinder engined car by the enterprise of Napier at the beginning of this century while the magneto had yet to establish itself, the problems of firing were extremely difficult to solve. So, in those days of heavy reciprocating parts and consequently sluggish engines, was the proposition of balance. Crankshafts were, not stamped in the modern style. They were cut out of the solid block of metal, involving an extraordinary number of separate operations by the crude machinery then alone available, and, of course, resulting in nothing like so strong a job for the quantity of metal used as is possible by the cheapest processes to-day. Then came Mr. Royce with the slipper flywheel in 1906, which is still the basic mean of dealing with the secondary vibration forces arising in the .crankcase. Moreover, eight months before the war had broken out, Mr. Louis Coatalen had built si#e valve V-type eight and twelve-cylinder engines for his Farman liplane, and the Sunbeam Company standardised, them. £33 TAX—3OO B.H.P. The war accelerated experiment and advanced standardised achievement in a manner which none would have dared anticipate. At the end of the campaign we had aircraft power -plant of 18 cylinders, and had acquired an extraordinary amount of knowledge which put an entirely neyv complexion on the problem of employing multi-cylinders. Advances in metallurgy enabled reciprocating parte to be lightened amazingly. We discovered that, by increasing the number of cylinders, the inertia forces were reduced greatly. We found out how to make overhead valves of a really reliable type despite the fact that we were running some engines at unprecedentedly high speeds, thereby attaining not, as is popularly mis-supposed, coarser functioning, but unprecedentedly smooth working—qualities appertaining more to the characteristic of power output by a turbine in utter smoothness and perfect balance. Incidentally, even before the war, the world’s records were held by a 12-cylinder engined Britishbuilt Sunbeam car, and one may note that this week Major H. O. D. Segrave is taking a new style Sunbeam ear of £33 taxation rating only, the 12 cylinders of which nevertheless produce 300 b.h.p. in a vehicle scaling loewt complete. The crankshaft speed is 6,000 r.p.m. which, far from being, as the popular prints of the day would have us believe, an “almost incredible speed,” represents two-thirds of the crankshaft speed attained by 10 h.p. taxation rating experimental engines to-day having onethird the number of cylinders.

In other words, we may see already other possibilities -of using multi-cylin-der engines, such as the 12 cylinder Napier 450 h.p. “Lion” with which Commandante Franco has made the only flight from Europe to South America accomplished without change of engine; or the Rolls Royce “Eagle” aero engines with which historic flights have been niade, such as the unprecedented one from Newfoundland to Ireland in a stage; and those from this country to Australia; also from this country to South Africa years ago. Lest anybody should doubt that this tendency to provide great horse-power from very compact and light units is quite impracticable, let him have in mind the showing of last year’s Blue Riband international, motor car races whorein the most notable victory went to the 2,000 e.c. or 122 cubic inches 12 cylinder miniature Delage vehicles.

A TWELVE CYLINDER STANDARD 13ED CAR ON THE STOCKS.

AU these points are something more than mere indications of the direction in which development is taking place. The conditions of such extraordinary services are such that the mechanism is vastly higher stressed, alike in the air and on the land, than was necessary for ordinary service. Incidentally, a manufacturer of world-wide repute, who I have not named in this article, is contemplating the introduction this year of a 12-cylinder engined car the power unit of which will be of qite a different constructional scheme. The fact that at present multi-cylinder power units are considerably costly is not an obstacle. It is merely that at present the public has not been educated to demand such products in a sufficient quantity to justify machines being laid down in vast series, on the American principle. Further, we are considering such advanced automobile engineering practice that, if we were to imagine the demand existing at the moment, still it would not be a wise thing for even the best educated motor manufacturer to undertake to supply it forthwith, if we are to understand that the public requires 12 cylinders to give the qualities of performance that that number can give, but which no lessor numbe • can furnish.

Any motor manufacturer could make you a I'2-eylinder engine which would give you no better results than four cylinders of the same net volume. But that is not the object of having the greater number of cylinders. The only excuse for proceeding from four to six cylinders, from six. to eight, and from eight to twelve, is that, at each separate increase, certain desirable qualities of performance not achievable by any other means can be made available. My only object in discussing this topic today is that at every stage of motor vehicle evolution it has been necessary for somebody to prepare the public mind for the thing that is about to become available. Actually, the 12 cylinderenginer standardised ear is no novelty, because Packard,' analysing the success of the 12-cylinder engined Sunbeam prewar racer—which it acquired during the campaign when we had to abandon that sort of enterprise— subsequently introduced during the, war, but before the U.S.A, had entered it, a standardised side valve 12-cylinder engined car which was a means of making the fortune of this high-grade American constructor. Much knowledge has been gained in the interval. Therefore that class of ear is not what that, or any other, firm would call the highest example of what we should require in a 12-cylinder engined machine to-day.

“STRAIGHT-EIGHTS” NO LONGER EXPERIMENTAL.

Il hat is desirable is that we should xecognise that the time has arrived when the mind of the motoring public throughout the world should begin to be exercised concerning eight and twelve cylinder engines for standard car service, just as twenty years ago one had to seize every opportunity to advocate the six-cylinder engines for car service. In the beginning, many accused one of simply asking the motoring public to demand trouble. We know how utterly that has been refuted by the actual achievement of the six-cylinder engine, which is now commercialised even for the cheapest classes of cars in the U.S.A., witness the Essex, which in a sense is setting a vogue—admittedly in lowly stressed multi-cylinder units only. In like fashion to-day, America is exploiting the advantages of the eight-cylinder-in-line engine, as distinct from the V-type of “eight” which, for reasons I need not go into here, is not theoretically the right form of construction. In Europe, racing aircraft engines, and two standardised chassis apart, we have not done anything notable yet with the eight-cylinder-in-line engine, though several tentative attempts have' been made and abandoned here, whereas highly stressed “straighteight” ears of moderate price already enjoy wide success in the United States. The only really notable propositions before the public to-day are the IsottaFraschini from Italy a iid the 39-90 h.p eight-cylinder-in-line engined standardised British Sunbeam. These, 'however, are forerunners. They prove that the thing can be done in practical and commercialised fashion, achieving great refinement and extraordinary flexibility without undue cost or sacrifice oi reliability.

From the eight to the twelve cylinderengine is not correctly to be described as but a step. On the contrary, if only by reason of the fact that the twelve cylinder engined car must, in the light of present knowledge, be constructed on the V principle, a very different series of designing and constructional problems is involved than present themselves in respect of the eight-eyclinder-inline engine. But they are not insoluble. Nor will cost be found at all insurmountable once sufficient experience is gained and, in consequence, pujflic demand are always concerned mainly with the scale of output.

IF THE CLUTCH DRAGS. The real remedy for a dragging clutch lies in a correct clutch adjustment, with inspection of the clutch brake, but knowledge of this is of very little use when you are trying to shift into “low” on some busy thoroughfare. Y 7 ou are ready then to accept any makeshift, just as long as it temporarily solves your problem. That is why you should learn to retard that spark if the clutch drags and offers you the difficulty of shifting into “low” or “reverse” without crashing the gears. When you retard the spark the engine naturally idles mower. That slows down the driving discs of the clutch, as well as the driven discs, which under ordinary conditions should be at rest when the clutch pedal is depressed. With the driven discs running so very slowly the shift, can usually be made without danger of clashing. THE NEW CAR. There are many important things about a new car that need special attention during the formative period of a car’s life. In addition to keeping the speed down to twenty-five miles an hour and ehanging oil each few hundred during the first 1000 miles- of service, the following should be observed: — Tightening of the fan belt. Tightening all locking nuts. Drawing up on spring clip bolts. Tightening of cylinder-head bolts. Frequent cleaning of the oil strainer. Taking up on water pump packings. Drawing up on bolts which secure the body, the engine to the frame, and those which hold the clutch-transmission unit to the crank case. Taking up side play to spring eyebolls. Tightening service brake-band adjustments. Inspection and tightening of timber chain. Correction of valve stem and tappet clearance. Readjustment of the clutch pedal to correct position. NEW PLUGS FOR OLD. Few motorists seem to appreciate that the points of a spark plug actually wear out. This is in addition to the cracking of the porcelain as a result of age. The point that comes down from the centre of the plug, which is the one that carries the high tension positive current, will appear to be eaten away. Plugs at 10,900 miles often will show so much wear at the points that the gaps will be much too wide for perfect firing at low car speeds. The points can be brought closer together but since the wear is uneven there is danger of not getting the right clearance. The safe plan is to instal new plugs.