OIL DILUTION

Hawera Star, Volume LI, 11 June 1932, Page 7

OIL DILUTION

USE OF THE STRANGLER

RESTRICTIONS NECESSARY

Oil dilution arises in several ways. It inevitably occurs in normal running, though only gradually, and the time comes when the lubricant must be changed. Wise owners do not grudge the expense. Before this time is reached, certain practices produce a dangerous degree of dilution. First among these is immoderate use of the air-strangler for starting, necessitated possibly bv inefficient ignition or poor engine tune in general. Often the air-strangler might be more properly termed the “oil-strangler.” That is what it becomes in the hands of some motorists. They “pull the wire” and spoil the engine. When the engine is cold the petrol cannot vaporise completely and only a part of the fuel drawn into the cylinder mixes with the air. In these circumstances, to produce an explosive mixture, more petrol or less air than normal is required. Hence the air-strangler, which effects this adjustment of the mixture. But the unvaporised petrol that remains in the cylinder dilutes the oil. Firstly, it denudes the cylinder walls of the wear-preventing oil film. In doing so it mixes with the oil and dilution results. Therefore, use the air-strangler as little as possible, and avoid carburettor flooding, which tends to produce the same results, or to aggravate them. With an efficient ignition system, with the valves in good order and no induction air leaks, starting is easy and strangling little required: and bv allowing the engine to run steadily and warm up before driving away the need for further air and oil-strangling is obviated. Dangerous degrees of oil dilution must be avoided, and can be without difficulty. Summed up, oil dilution is caused by carburettor flooding or immoderate air-strangling, the use of cheap adulterated petrol, and crankcase flushing; with petrol or paraffin. It is obviated by keeping the engine in tune to render starting easy, allowing the engine to warm up before the car is driven, using only first-grade fuel, and using a light oil for crankcase flushing. By conforming to' these requirements engine longevity is assured.— Austin Magazine.