From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The benefits and functions of automobile oil filters, featuring a reprint from the National Bureau of Standards and an advertisement for Luber-finer.
Identifier | ExFiles\Box 135\3\ scan0280 | |
Date | 3rd August 1935 | |
[Left Page] [Red Box Text:] Luber-finer users alone can be assured that their oil will give them perfect lubrication due to the fact that the Luber-finer has the ability to control crankcase acidity. Not only is it impracticable for the motorist to determine for himself the acidity of the crank-case oil, but even if the acidity were known, there is not sufficient information on this problem to state whether the oil could safely be used without danger of bearing corrosion. Intensive investigations on corrosion of bearings are being carried on in a number of laboratories, leading towards the establishment of the safe limit for oil acidity and toward the development of non-corroding bearing materials. Until these investigations are completed, the motorist should follow the recommendations of the filter manufacturers (or the car manufacturers if filters are standard equipment on these cars) regarding the draining of the crankcase oil and the replacement of the filtering element or filter. One other point should be taken into consideration. Before a filter is first installed in a car which has been run for some time, the crankcase should be thoroughly cleaned. If this is not done, no harm will result but the life of the filtering element will probably be considerably less than that stated by the manufacturer, as the result of the retention in the filter of dirt, sludge, asphaltenes and carbonaceous material which had accumulated in the crankcase before the filter was installed. VII. GENERAL CONCLUSIONS While an oil filter is not essential to the operation of an internal combustion engine, the use of one of the more efficient types will permit extending the period between oil changes, and the saving in oil thereby effected may, in some cases, more than cover the cost of the filter. Also the use of an oil filter may reduce wear of cylinder wall and piston rings and in this way minimize oil consumption and possibly fuel consumption. A considerable number of commercial oil filters, which will maintain oil in clean condition for long periods of time, are available, from which the car owner can make his choice. Some of these filters will maintain the acidity of the oil at low values and thereby minimize corrosive effects, particularly on the newer bearing materials. [Advertisement Section] Above Letter Circular LC-446, reprinted by permission of the NATIONAL BUREAU OF STANDARDS and made available to the public through the courtesy of the Engineering Department of:-- Luber-finer New Oil Every Mile Refined as you drive The Only Genuine Oil Refiner For Your Car LUBER-FINER (ENGLAND) LTD. (Associated with R.{Sir Henry Royce} H.{Arthur M. Hanbury - Head Complaints} Collier & Co. Ltd.) South Yardley, Birmingham Telephone—ACO. 1681 Telegrams—COLSPAR, BIRMINGHAM [Right Page] NOTE—All underlining and comment made in red ink are made by Luber-finer, Inc., and were not included in the bulletin as issued by the National Bureau of Standards. OCB:MLK 111-8 (Reprinted by Permission of the National Bureau of Standards) Letter Circular LC-446 DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS WASHINGTON August 3, 1935 AUTOMOBILE ENGINE OIL FILTERS The quality of commercial oils for lubricating automobile engines has been improving rapidly in the past few years, largely as the result of new and improved methods of refining. Thus, not-withstanding the higher engine horsepower, higher engine speed, and more severe engine operating conditions of recent models of cars, lubricating oils are now obtainable which deteriorate much less in 500 miles of operation than did the oils available a few years ago. Offsetting this, the customary period between oil changes has been gradually increasing, so that in general the condition of the crankcase drainings is about the same as that with the older oils run for shorter periods of time. In order to extend still further the mileage between oil changes, many motorists are now installing efficient oil filters. In many cases, an oil filter will keep the oil clean for thousands of miles of operation and it has been reported that use of oil filters may result in a considerable reduction in wear of piston rings and cylinder walls. The National Bureau of Standards is not in a position to give detailed information regarding the efficiency of any particular make of oil filter, but the following discussion may be of assistance in the choice of a suitable oil filter for any particular purpose. [Red Box Text:] Any efficient filter will remove "a" and "b". Only Luber-finer contains the material recognized by all refinery engineers as capable of neutralizing acidity, and scientifically removing (a), (b), (c), (d), (e), (f). In order to understand the function of an oil filter, it is desirable to consider what changes take place in an oil during use. These changes are mainly (a) contamination with road dust, (b) contamination with metal particles from wear or abrasion of engine parts, (c) formation of asphaltenes as the result of partial oxidation of the oil, (d) increase in oil acidity, (e) dilution with the less volatile portions of the gasoline not burned in the combustion chamber, and (f) contamination with water formed by combustion of the fuel. I. ROAD DUST AND METAL PARTICLES Road dust invariably gets into the oil during use, either through the intake manifold or directly into the crankcase through the breather pipe or other openings. In extensive driving over unpaved roads or in localities where dust storms are prevalent, large amounts of dust may get into the oil in this way. The use of an efficient air filter will remove a large percentage of the dust entering the intake manifold, but even so, the finer particles tend to work past the filter. It is true that some of these particles are so small that they probably cause little wear directly. However, these fine particles may tend to form larger agglomerates with the carbonaceous material resulting from decomposition of the oil, in which case, they may cause appreciable wear of cylinder walls and piston rings. [Red Box Text:] Luber-finer prevents this wear by removing impurities from the oil substantially at the time they are formed. With new cars, there is always the possibility that all the core sand used in the casting has not been removed and this may get into the oil. Also there may be metal particles from the machining operations which were not entirely removed before the engine was put in operation. Wear and abrasion of the various moving parts of the engine may result in the accumulation of a considerable amount of metal particles in the oil. These particles are ordinarily so small that they do not cause abrasion directly, but they may do so if they form agglomerates with the asphaltenes or carbonaceous material in the oil. | ||