MOTORS & MOTORING

Dominion, Volume 14, Issue 81, 30 December 1920, Page 9

MOTORS & MOTORING

(By "Clutch.")

Suspension. ' It has often been suggested by comfort enthusiasts, says the "Autocar,"' that I there is no technical reason why a small car should not be as well , sprung as a , big car. But theory is often complicated by practical factors, and when the small car is put on to the road -its suspension is usually hampered by two special considerations. The first is that its load bears a very high proportion to the total weighii, and £ince load is variable, the springs have to cater for an unusually high range. The load of the average 10-h.p. two-seater varies from one Bst adult without . luggage to four 12st. adults (allowing for a crowded dickey) •.with luggage, say 50sti'. in all. If the chassis weighs 12cwt., the difl'erencu between Sat. and 50st. is far more serious " than it would be on . a 40cwt. chassis. tSecondly, the l>ig' car has big tyres, which may be run at pressures ranging from 40 to 601b. But the Utile oar has little tyres,'which "feel' their rims" if they are not blown up pfttty hard and which hump like solid tyres if they aro .inflated hard. The small cat man who lives among bad roads must allow for tliese factors. All he can do is to fit the, best shock absorbers, restrict his car to a definite load, specify springs, to suit that load, and fit oversize tyres,. Over-stiff Springs. Where the springs are too stiff for comfort an obvious suggestion is to removo a leaf of tho spring; but'there aro two difficulties. First, doing so may. overstrain the remaining leaves, and-eventu-ally, lead to fracture; secondly, there may not be enough clearance between axle and frame to allow for tihe increased deflection there will be. None tho less, in some oases excellent results are obtained by removing a leaf and then fitting a damper. At tho .same time the main trouble with over-siiff springs is that tha small shocks are not well dealt with; and, in most cases,* the simplest mothof' Is to fit "supplementary spriijgs," which are small spiral springs fitted in place of the usual shackles. These springs take up all i i'he petty vibrations (with the help of the tyres), 'leaving the main laminated springs to deal with the large shocks. Engine Design. . The American automobile industry is entering on a new era as regards the design of its products. Many factors have combined to make necessary certain changes in the. design of automobile engines. The increasing demands forpetrol have made the supply such a tight fit that steps have, got to be taken to conserve motor fuel as well as to increase ilie If the automobilo engineers can design engines that.will' use only half the quantity of'fuel for a given mileage it is the eamo as increasing tho supply of petrol 100 per cent. Practically all: American engineers are working on .this problem and one of the first points, of at'.lick is going to be weight. Light weight, together with proper distribution of weight in a motor-car, means low petrol consumption, low oil consumption, greatest tyre mileage, comparative freedom from expensive repairs, and Msy riding. Giant Pneumatic Tyres. One of the most pronounced, developments in evidence at Olympia Motor Show, London, was the increasing popularity of pneumatic tyres for vehicles in the heavier classes. AVhilo at present no British manufacturer has announced a chassis specially designed to run on pneumatio tyreo with loads exceeding 30 to JOcwt., and there is no'general inclination to recommend air-filled tyres for the heavier classes of vehicle, the majority of makers are now prepared to admit that there may' be at least possibilities in the way of ultimate economy in their .use. ' British'.makers, in other words/ are not yet prepared to go as far as those in America, where an increasingly large proportion of-'commercial vehicle makers are standardising giant, pneumatics in their specifications, and some are actually making speoial chassis for use with this type of tyro, • A Deck Chair Side-car, Tho value of comfort for the side-cm passenger,, especially when touring over long distances, cannot be overestimated, and the design of the seats, especially in the case of two-seater side-cars, should enable the passengers, sitting in a more or less confined space for long periods, to alter their position at: will. A side-, car with an adjustable 6eat and other novel features will shortly be produced. In it the principle of the i?eck-cliair has been utilised to advantage. The forward seat consists of an upholstered roll, suspended on a bar carried in slots in tho body. The fabric extends from the roll upwards', across a spring bearer to a crossbar, and is fixed to two -supports, which are pivoted on the inside of tho body. The back -rest is held in the' re. quired, position by tho arm rests, which are capable of being locked. This seat "can be removed entirely, or adjusted to any position. If desired, the rear seat back rest may be raised, and the front back rest lowered to its fullest extent, and a recumbent position obtained for a single passenger. The chassis follows more nearly conventional design, and is as simple and'light as is consistent'with the strength called for by the two-seater body. . Engine Testing. ' Engine testing in the average American factory, differs very considerably from European practice, says the "Autocar." Tho dominating idea is "to get as high a degree of manufacturing accuracy as possible, and to assume that the..finished article isVright. In many cases the socalled test is nothing nioro than a run-ning-in. Ford, for. instance, has'the . engines placed on blocks and driven by electric motors, tho being measured and indicated in- an instrument room quito independent of the test room. The instrument room operators can read at all times the resistance being absorbed by the motors, and, when this has been reduced to the required figure, it is they who give t.he signal to • the test room operator that the engine can be taken oft' tho block. Ths system' limbers up the engine and assures uniform freencas throughout the serios,' but it does not constitute a test of the power developed by the engine. Jn many other cases, although the engines are run under coal gas, or petrol, they aro only really being worked in, and ar.e not tested for power. Tn only a few of tho highest-class fac : tories is there a real engine test, for power, consumption, noire, etc., with an examination of the power plant on coming off the block. Acetylene Lighting. The use of acetylene for' lighting cars has received rather a setback, due, in the first" case, to a scarcity of carbide, and, in the sccoml, to a more general adoption of systems ot electric lighting and starting combined with the coil end accumulator ignition. Many motorists aro not e.namonred. of the latter systems, and would prefer tho simplicity of tho magneto with tho gas system of lighting as separate units. There is no doubt that there is a wide field still for the acetylene light, and properly installed with well-made appliances, conveniently designed, there is no doubt about its efficiency. Its only drawback is the cleaning and charging of the generators. But this, given good equipment, Is really a simple matter, and tekes a very small amount of time. With good filters, readily 'accessible for cleaning and replacement of the filtering substance, the trouble with choked burners' is easily avoided. The main- causes >of choked burners sire unfiltered gas and allowing the, flame to die down. As noon as the gas supply shows signs ol giving out, the bnrnor should bo extinguished and the generator re-oharged. If this is done

and the filter is working properly, choked and'carbonised burners 'will' be, a rare uccurreucu. Some people sttm to' think tl.at tha cost of acetyleno gas is an extra which increases the cost ot motoring over and above the self-general cd current of tho electric system.- They forgot that petrol is iiccossary, over and above that used for the propulsion of tho car, (o produce tho current. Acetyleno has tho advantage of being independent of the power plant and much less liablo to delaiigement than some of the really complicated electric systems now in vogue. •There are, of courso, "compensating draw'backs," as somo unconscious wit has re. marked, in both systems. For cheapness in first costs the acetyleno system scores —and tiiis is a consideration in theso days. Commarclal Alcohol. . News, comes from London of a new process for tho extraction of commercial alcohol which, though still in the experimental, stage, is said to be capable of producing a satisfactory motor spun'. Tho work has been carried oil ill Lngland, where alcohol unci derivatives hu\e been recovered from coke-oven gas by « sulphuric acid contact process. An average yield of 1.6 gallons of alcohol per ton of coal carbonised is reported, and it is calculated that if all of'the cokeoven gas from the coal reduced to coke in England during 1918 had been subjected this process, more than 23 million gallons would have been recovered. Efficiency of Motor-cycle Engines. The efficiency of high-class English small-powered motor-cycle engine is remarkable.. Some few years back eighty miles an hour was deemed a performance of merit for a 60-S0 h.p. car on a racing track. To-day a2j h.p. "A.J.S." motor- , cycle (cubic capacity 350 c.c.) has proved, itself capable of negotiating a flying kilometre at the rale of slightly over 80 miles an hour ; on Brooklands iVuckThis is a marvellous achievement for such a small engine., Five miles at the rato of 69.8 m.p.h have, also been credited to the same make of machine. Americans Limit Output. Many of the American makers of wellknown cars are now limiting production to the demand. In Detroit: alone-the hub of automobile construction m 1 tho States-there was a drop of about 10 per cent, in production for September, as against the previous month's output—or about 45 per cent, below the manufacturing schedules outlined at the beginning of the year. Cleaning the Cooling System. To give «• thorough cleansing to the cooling system, disconnect the short section of lioso between the 'bottom of the radiator and pump, connect the garage hose to the water pump and a longer section of hose'to the .bottom pipe of the radiator and lead it outside. Plug the overflow tube with a cork or rubber stepper. Turn'on the water after starting the engine and it should be pumped through the water jacket and radiation till it runs clear. If the radiator and water jacket of the engine are found to contain.,considerable scale or rust, it may be necessary to flush the system out with a solution of hot water and washing soda and it may even be.desirable to allow the' washing soda solution to remain in the water system oven night to make sure the scale is .loosened. Germany's Petrol Shortage. At a recent general meeting of tho Society of German Motor-car Manufacturers complaint was • made that sales were badly "blocked by the'shortage of petrol; that the importation from_ the Unitod States, in spite of very considerable orders, was most unsatisfactory, seemingly on account of an enormous consumption in the United States; that it was hoped that Rumania would soon be able (as in former times) to again take up its petrol export to- Germany. In the course of the meeting it was-furthei stated that it wasjil'anned-to.work hand-in-baml with the Austrian automobile in-1 dustry concerning all economic Questions. Cleaning Contact Points. The contact points of the ignition system or- the surface of the motor commutator cau best be cleaned by what is known as cuttlefish paper, which is finer, than the finest sandpaper. This paper, cannot always.be obtained:at.hardware stores, but is on hand in dental supply, stores.