THE MOTORIST

Northern Advocate, 22 April 1933, Page 2

THE MOTORIST

UPPER CYLINDERS,

VALUE OF LUBRICATION

Of all the worl dug parts of a motor ear engine the pistons undoubtedly present the greatest difficulty in regard to adequate lubrication. When an engine is thoroughly wariji, conditions (states an article in the Motor) are reasonably good, because the oil is thin and is thrown around insido the crankcase in considerable quantities. A great deal of it naturally comes into contact with the cylinder walls, particularly the lower parts thereof. Lubricating the Wall. The upjrer part of each boro depends for lubrication upon oil which is carried up by the moving piston, and it is difficult to strike a happy medium in the piston ring design so that, while lubrication is adequate, oil does not actually pass upwards in any quantity into the combustion chamber, where it would be wasted and cause smoking. Another important point, is that when an engine i« cold the oil is so sluggish that quite an appreciable time may elapse before any lubricant readies the cylinder walls. During this time the pistons are rubbing no and down in practically a dry condition, Tests have shown that in these circumstances considerable Avcar can Occur in a short time, particularly if an inconsiderate driver expects an engine to pull the car on the road with scarcely any preparatory warming up. Good Results, These are the main reasons which account for the fact that many ownerdrivers have obtained excellent results by employing special upper cylinder lubricants added to the fuel in the tank. Such lubricants pass through the carburettor and into the engine, so being carried directly to the upper parts of the cylinder bores. There is also considerable evidence that they lubricate valve stems to eome extent. Their chief function, therefore, is to lubricate parts that are ordinarily apt to suffer from neglect, so preventing wear, particularly when starting from cold. Quantities Required. With every tin of such lubricants a measure is usually supplied'which shows the quantity of the special oil ■which should bo added in relation to the number of gallons of fuel put into the tank. We have used such oils on a number of our staff cars, and have found them to be efficacious, especially during the first period in the life of a car, when the pistons, valves, etc., are of a fairly close tit. They undoubtedly reduce cylinder wear and also help to keep the piston ringe working freely in their grooves. Naturally the efficient lubrication and fit of pistons, bores and rings prevents the crankcase oil from passing into the combustion chambers, and thereby automatically reduces the rate at which carbon is formed. ,

There arc 210 listed camping places in the North Island and 72 in the South Island.