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STUDY of the foaming of engine oil by the CLR Group on Foaming has led to the development of what is called antifoam agents, which, when added to the oil, eliminate foaming under most conditions. These inhibitors of foam, the authors report, have no detrimental effect on the oil. Nonfoaming engine oils are now available for the Army and Navy; and, as far as can be determined, complaints from foaming of Army and Navy specification engine oils have now been eliminated.

ONE of the simplest and cheapest methods yet devised to augment cutting tool life, and at the same time increase cutting speeds, is described in these two papers by the authors, who pioneered in developing the novel hi-jet system, which substitutes a fine, forced jet of oil for the customery flood type of lubrication during cutting operations. In Part I, Mr. Pigott reviews the improvements resulting from applying cutting liquids in the hi-jet manner. He compares the results with those obtained under the former system. He also describes the adaptations of various recording instruments and other improvements developed during the running of hi-jet tests. In Part II, Mr. Colwell describes many practical applications of hi-jet. Mr. Colwell considers the method to mark a revolutionary advance in the art of removing metal. He points out that the combination of cooling plus oil vapor lubrication supplies the factor which has produced superior results.

Some of the problems encountered in the use of ruthenium as a NOx reduction catalyst are described. The major problem of volatilization in high temperature oxidizing atmospheres has been overcome by providing a stabilizing matrix for the ruthenium. The stabilized catalyst, however, does not have good CO and HC oxidizing performance, such as is required when the NOx catalyst is used for oxidation under cold start conditions. Coimpregnation of Pt and Ru is ineffective in improving this situation, and it was necessary to develop a novel procedure to improve catalyst oxidation activity. Engine dynamometer tests showed that the final catalyst performs well under all of the conditions to which it is subjected. The question which remains unanswered is the durability of the system.

This paper discusses the major difficulties experienced in the operation of two-cycle engines. For the most part two-cycle engines operate under full load for sustained periods, thus developing high engine temperatures which promote deposit formation in engines. Problems analyzed are spark plug failure, preignition, engine wear, and rust and corrosion. The paper describes test procedures used to investigate these problems, as well as illustrating how the difficulties could be minimized by use of properly formulated additive-containing oils.

The effects of oil viscosity, fuel vapor pressure and, to a much lesser extent battery capacity, automatic choke setting, and starting procedure on the starting ability of four cars equipped with small engines were investigated at-10F. Oil viscosity and fuel vapor pressure were shown to be major factors in low temperature starting. A “start but not run” phenomenon was experienced in all cars.

Combined efforts by oil companies and engine manufacturers have improved the overall efficiency and performance of two-cycle gasoline engines. One striking trend has been toward the use of leaner oil-fuel mixtures to accomplish lubrication. The use of less oil reduces smoking and air pollution (important in two-cycle automotive engine operation), reduces engine port deposits, preignition, and cost of operation. Experience has shown that the composition of the oil becomes increasingly important as its concentration in the fuel is reduced. Lean mixtures of some conventional oils are not satisfactory, and with all oils some lower concentration is reached where serious problems are encountered, such as lack of lubrication, increased engine wear, and decreased engine cleanliness.

The development of an improved Reciprocating Viscometer for use in predicting low temperature cranking characteristics of engine oils is described. Correlations between full-scale engine viscosities and viscosities determined using the Reciprocating Viscometer are included along with repeatability and reproducibility data obtained at 0 F and -20 F in an ASTM round-robin evaluation. Results show that this viscometer can predict the low temperature cranking characteristics of engine oils.

Factors contributing to winter hot starting difficulties encountered in some modern automotive gasoline engines were investigated in a two-phase study. These factors were evaluated first in test cars and then in a test stand engine under more closely controlled laboratory conditions. The effect of oil viscosity on an engine's hot cranking torque requirements and the ability of batteries at various charge levels to supply sufficient power to satisfy these requirements were extensively investigated; whereas the effects of viscosity index improvers, precombustion reactions, engine hot soak time, and oil temperature were only briefly investigated. The present ASTM D 445 viscosity at 210 F was shown to be inadequate for predicting the hot cranking performance of multigrade oils and a method for determining an oil's hot cranking “engine viscosity” was developed.

RESULTS of a laboratory study of some of the factors causing wear, scuffing, and spalling in passenger-car engines, with emphasis on the lubricating oil variables involved, are reported in this paper, which is part of the Symposium on Cam and Tappet Wear. The tests show that piston-ring and valve-lifter wear and spalling of some valve-lifter materials seem to be greater with low-viscosity oils such as SAE 5W-20 and 10W. Certain antiwear lubricating oil additives reduce valve-lifter and ring wear but may increase spalling of chilled iron lifters. However, using an oil with good antiwear properties for engine break-in will not prevent future lifter wear if the engine is operated with an oil of poor antiwear characteristics.