DEVELOPMENT and service properties of a new compounded diesel-engine lubricating oil are described in this paper. Properties of the oil brought out by the author include anti-ring-sticking value; prevention of lacquer formation; reduction of carbonaceous deposits; that it is non-corrosive to all types of bearing metals; and that it reduces piston-ring and cylinder wear at both high and low temperatures. Although recommended specifically for diesel engines, the oil also is suggested for gasoline engines particularly where engine deposits are troublesome.
The research program leading to the development of this product included a chemical investigation of the fundamentals of lacquer formation and ring-sticking, the construction of a special research laboratory, the design and operation of many special laboratory devices, the preparation of hundreds of chemical compounds, full-scale engine tests in the laboratory and in the field, and the construction of a plant for manufacturing the compounding material selected.
Data are presented comparing the product with straight mineral oils and corrosive-type diesel lubricants. These laboratory tests required a total of 26 engines which included 7 makes of diesel engines and a few makes of gasoline engines.
A fundamental property of lubricants is described which relates to the highest temperature at which an oil will wet a metal surface with a fluid film of sensible thickness. Data are presented showing that engine scuffing difficulties are prevented by lubricants having good spreading properties at high temperatures, and that the new lubricant possesses superior spreading characteristics to which its breaking-in and surface-conditioning properties are attributed.
The comparative economics of engine operation with this new type of lubricant and straight mineral oils is discussed. Application of the oil for cleansing or purging of both diesel and gasoline engines is explained.