KEEPING THE OIL COOL

NZ Truth, Issue 1190, 20 September 1928, Page 15

KEEPING THE OIL COOL

Splash System Favored— Ghance For Inventive Brains

MOTORISTS must be particularly interested m the:efforts that are ! V1 being made adequately to cool the lubricating oil.

•"THUS bearings shall be fed with cool 1 oil Instead of lubricant which is at a temperature near or above that of boiling water. • It is probably not generally realized that a crankshaft performing reasonably hard work, say pushing a car at 35 to> 40 m.p.h., may reach a temperature of 200 degrees. The oil, therefore, must reach praptically the same temperature, and m full pressure. lubricating systems, the same oil that passes. through the main bearings is carried onward to the big ends, so that the latter are fed with hot, thin, oil. . ' The Ford, for instance, has retained; this system,- as by its means,. the. big ends are fed with comparatively . cool oil.' •. ' '• ' ' • " •-.',■ ■.'........ ■. With the pressure system, the only way the oil can be cooled is for it to be taken out of.. the. sump and, sent through some type or other of. cooling apparatus. ; . . Late researches into engine operation have demonstrated a real need for reducing the oil. temperature. Some, makers have already increased the size of their sumps, arid! ribbed them heavily, so that the heat is carried away by the rush of air underneath the car. While the .system helps to cool the oil, it does not go far enough, and manufacturers both of cars and of accessories are busy on the job of developing thoroughly efficient cooling apparatus. > One system which has been developed recently called for two independent pumps,, one supplying the bearings while the other forces oil through a radiator placed at the back of the water radiator so that it participates m the

rush of cool air thus induced byjthe fan. The. cool oil is fed back to a well from which the bearing pump takes its supply. ■ ■ ... / .. ' . -, r. The super-charged . Arrol car ,hag another system. whereby the oil is con -f ; taihed m a tank between the front dumb irons, where it is fully exposed to the flow of cool air. • Another, big maker— Peugeot — has adopted a' forced system whereby oil is taken through the radiator from a by--pass valve. • • Most racing cars are iio.w fitted with oil cooling devices of some form brother; and it is :only a matter, of 'very. short time before passenger cars be : fitted^ in a similar way. . '■■-^, >''"■}'■ \ Experiments with .the. Peugept^systemrin operation on. a fast touring car; showed • that .whereas, the. , .working temperature of the- oil without an oil, radiator ;in operation was 195 .degrees, the temperature Was reduced .to 100: with ;the radiator m .action.. . . . ■ ; : Furthermore, and .moa.t .Important, it was found that when the oil tempera-, ture was kept low there, .was. a. marked decrease m -consumption, v amounting from 15 to 20 percent. The , importance of keeping; the oil cool when the engine is under ' pressure can be gauged when it is _, considered "that" the' strength 'ofwhlte metal decreases .quickly after a temperature of 200 degrees is reached, and that at 300 degrees It becomes fluid. ; . : In a country such as New Zealand, where, m summer engines run ; under very arduous conditions, this matter; of oil cooling, is of great importance, and developments will be watched with keen interest by motorists who are more than mere drivers.

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