MOTORS AND MOTORING

Dominion, Volume 10, Issue 3172, 24 August 1917, Page 9

MOTORS AND MOTORING

(Ry "Clutch.")

Enflinc Speed. ' In a very largo degreo thn power developed by ii uiotor-cyolo ongino dejiciuls upon ite speed In revolutions jior minute, ■and tlio designer has to take this iu'nocdunt strictly in Belectiiiß; flio diiueneional characteristics (if the cylinder, ns they ivpyly to boro .'Hid stroke. It is sometimes said that ono engine is much "faster" than nuother—not' as regards tho speed attainable mi tlio road or track, for there othor factors are introduced—but in its own «no«l or "turning over." Tho gear ratio determines lo a very large extont— almost entirely, in fact—the number of engino revolutions pei- niuiute nt »i given epced'of the ma. chino. oh a-wholes,but if. the ongino is being run independently of tho road wheels by means of the clutch or the reino'yai of tho transmission, gear, then undoubtedly will ono'engine rovolvo more rapidly, than another of <ho samo proportions and general character. Tlio. explanation- in' such cuses must bo sought, union's factors'which', lnivo nothing to do with tho propelling gear,' such. lx>ing;in the oircuinstances.eliininated, and it -will be found in'the greater accuracy of de-sign-and lesser frietional. effocts -which., ono engine, possesses as compared with another. The use of tyill or roller bearings for main shafts and connecting rods increases the freedom, aud'liveliness of an engine;. and, indeed, anything,-asinay' be expected, las, tho.eimo Tesulf which tends to reduce friction. -ffhenbearuigH have been in"-use for long" periods, tho engine generally becomes somewhat sluggish, but" tho'effect produced' by'flushing out with ' paraffin is. remarkable.-_ It seeing .to' infuse ntw life into the engine, and tho response'to ilie opening of tho throttle, no matter how slight the movement, is noticeably' improved: ' Simply, the clogging effects of thick and stale oil have, teen removed,' thus, reducing' the' friction or breaking tendency in the bear, ings,. This/is, of course, reflected' in tho superior running rf the maohino when tested'on the road, and if tho'process were repeated more often than on tho average is the case, loss would be heard of engines-failing in epeod and'power. Porous Tubes. Porosity in inner tubes.is tlio result of tho rubber becoming perished, and this genorullv arises from the heat and friction engendered in the tyro when running.. Its growth. may be deferred to a certain extont -!f tho tube bo bathed in water whenever it is. removed from the cover;.' When a tube has beconio so bad that it will only hold up for a few hours, its condition, is practically hopeless. Sometimes, however, really remarkable results may be obtained by inserting a filling liquid into tho tube by moans of the dismantled valve. Old-time cyclists used to uso' a mixture of treaclo and water, but- this is- uot advisable, as it is very "messy in case -of -a' puncture, and, moreover, it is likoly to loosen any patches oa the tube. A better- liquid, acoording to an English ivritor, is mado by mixing a teaepoonful of flour in a wineglassful. o£ water. This is introduced into tho tube, and -the effect of. the internal air pressure is to force the minute grains-of flour into Iho small holes of the mbber and seal - them .. in. a very effective ■'. manner. Improving, the Carburettor. One result'of the present shortage and high'prica of petrol should bo to focus more and inoro attention upon, tho problems of oarburation. Tho carburettor as at present designed - oortainly gives good results when using tho fuels to which wo have been accustomed in past years, but the number of motor vehicles put into use is being increased at an enormous late each yoar, and tho inroads which are being made into the limited stores of motor spirit—as wo know it at present—suggest-that it is vital that every effort should be made to ensure that none of it is wasted. In America, whero the: fuel' problem is becoming acute, it has "been borne in upon those who have been investigating the subject that tho carburettor of Jp-day iias ceased to be more than a measuring device, and that tho true vaporisation takes places in the intake manifold. This" suggests that ideas regarding carburettors are in great need of revision in the direction of the fitting being considered not merely as a unit by itself, but as. a part of a completo vaporising devico. Here and There. The vibration on motors travelling over uneven surfaces, or at a rapid rate on the best of roads, is so great that frequently nuts and' bolts, .screws, and sometimes tools and spare tyres, are loosened and lost. The rush of air and the noise of the ear itself i 3 so great that all other sounds are drowned, and tliereforo the occupants have no warning that something is Joose, unless tho rattle is very pronounced. The practice of some motorists is that when a lengthy and fairly steep bill is reached- the engine is deolutched and stopped, and tho car allowed to coast down the slope. Any foreign noise may then be heard, and from its nature the driver will invariably be able to determine whether it requires immediate attention or if it can be left until the next halt. The engine is restarted by tbe Impetus of tho car, the oiutcli being gradually let in before the machine reaches the foot of the hill. The likelihood of finding oneself without matches when miles away from anywhere is a contingency that might occur to anyone. But it is fairly easy to obtain a light by detaching vne' of the high-tension wires from its sparking plug and attaching it to a,spare one. Piaco the plug on a convenient part of the framo, so that .the current can earth readily. Dip a piece of tissue paper into petrol and place in.the spark gap. Switch on, and turn the engine round, and the spark .will readily ignite the inflammable paper. '. ■ - Forgetfulness and carelessness are expensive traits usually, whether applied to motoring or business. One little careless act which will generally culminate in a considerable item of expense is that of frequently folding . tho hood back whilst it is still wet.and leaving it in that state in the garage. To rot a hood quickly no better method could be devised. Sometimes it is noticed that tho lubricant in the gear box disappears very rapidly, and to many it ia a mysterious phenomenon. The cause is the heating of the gear box, which expands the air in tho upper portion and' forces the lubricant out through the bearings. Ii tho fault is very persistent it can be remedied by drilling and threading . a hole in tho top of tho gear box and screwing into it a small piece of pipe. Occasionally troublo is experienced by the failing to locate minute punctures in tlio inner tube. Even when tho tube ia pumped almost to bursting prossuro the Icll-tulo bubbles often fail to show theniselves. If tho tube bo slightly Mated, then wound round spirally with string, a great pressure can bo forced in without risk of a burst:. Even tho tiniest liolo will bo. found by this moans. liighting-up time: To-day,. 5.17 p.m.) next Friday,. 5,34, p.m.