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Performance tests at full rack and 1400 rpm using a single cylinder diesel engine were made to determine the effects of three different micronized coal-fuel oil slurries being considered as alternative fuels. Slurries containing 20, 32, and 40 percent by weight micronized raw coal in No. 2 fuel oil were used. Results are presented indicating the changes in the fuel flow rates, concentrations of SOX and NOX in the exhaust, exhaust opacity, power and efficiency, and in wear rates relative to operation on fuel oil No. 2. The engine was operated for 10 hrs. on all fuels except the 40% by weight slurry. This test was discontinued because of extremely poor performance. Results indicate that the coal is largely inert in this situation and will cause a net increase in oil used and very rapid wear.

The cold pumpability characteristics of a group of commercial premium crankcase oils were evaluated at 0 and -20 F in a test stand engine. A test procedure was developed for these evaluations which gave results that compared favorably with those obtained in two popular makes of test cars at 0 F. In a second, more detailed, phase of this study, the effects of fourteen factors on the cold pumpability of several crankcase oils were investigated. The data from both phases were then analyzed to determine if an oil's cold pumpability in an engine could be predicted from its CCS viscosity, Brookfield viscosity, GM pour time, or ASTM pour point.

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.

The cold pumpability characteristics of nine commercial crankcase oils were evaluated using a V-8 engine and a bench test. These nine oils included most of the SAE viscosity classifications. The engine data were used for evaluating the ability of the bench test to predict the cold pumpability properties of crankcase oils. Additional tests were conducted to study some unusual cold pumping properties of two of the oils. One of these oils was very soak-time sensitive, while the other was found to improve in pumpability after only brief use in the test engine.

REACTIONS of unsaturated fuel constituents with oxides of nitrogen, formed during combustion, play an important part in formation of engine deposits. Engine varnish, the organic binder in engine deposits, results in large part from reactions of nitrogen dioxide with gasoline constituents. Simplified kinetic studies indicate that nitrogen fixation and amounts of nitric oxide present in exhaust gases could be predicted. Tests have demonstrated that only under conditions leading to appreciable nitrogen fixation does heavy engine varnishing occur. Because commercial engine oils are fairly resistant to oxidation, it is likely that current deposit problems result from the nature of fuel and prevailing operating conditions. Under average driving, low-temperature operation, lean mixtures with consequent high nitrogen oxide content contribute much to varnish formation.

Vapor lock characteristics of a group of late model cars were evaluated, using a new part throttle procedure for simulating high temperature operation. Ten cars using three reference fuel series having diverse front end volatility characteristics showed an average difference of 1.3 lb, RVP with the low and high volatility fuels. Comparisons of wide-open throttle and part throttle requirements using intermediate volatility fuels showed an average decrease of 1.7 lb, RVP at wide-open throttle. Temperature for a vapor lock ratio of 15:1 was found to be superior to other expressions in predicting vapor locking performance of gasolines.

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.