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Viewing 16411 to 16440 of 16616
1938-01-01
Technical Paper
380145
T. A. Boyd
THIS paper deals with the road-test portion of the extensive efforts made during 1937 by the Cooperative Fuel Research Committee to get as precise a correlation as possible between the laboratory knock ratings of automobile fuels and their corresponding ratings in cars on the road. It is anticipated that the comprehensive results of car tests reported here, taken together with the results of the laboratory rating program reported in the companion paper, will serve as the basis of the continuing studies aimed at developing the best possible correlation between road and laboratory knock ratings. Work similar to that reported here has been conducted concurrently in England by the Institution of Petroleum Technologists, using British cars and fuels. An exchange of information between the British and American groups working on this problem is being made.
1938-01-01
Technical Paper
380125
A. E. Becker
THIS paper is a progress report of the Cooperative Fuel Research Committee, dealing with the laboratory section of the study of the knock-rating correlation problem. It is proposed that these results and those obtained on the road be the basis for further study aimed at the development of better correlation between road and laboratory ratings.
1938-01-01
Technical Paper
380121
C. H. Baxley, T. B. Rendel
FOLLOWING the adoption of a suitable design of engine and a tentative procedure for operating this engine, the work of the Volunteer Group has covered the investigation of other methods of measuring cetane number of Diesel fuels looking towards a simplification and improvement of reproducibility of the procedure. Results of a second series of cooperative tests are given, using the procedure adopted in the Group's last report together with a series of tests on the same fuel using the critical-compression-ratio method with an interval timing-control device. Results of the first series do not show such good agreement, the grand average deviation on twelve samples being of the order of ±1.9. Results of the critical-compression-ratio tests show improved agreement due to better standardization. Tests on three alternative methods based on the delay method, but using different instruments for recording the delay, are given. Results on two different full-scale engines also are presented.
1938-01-01
Technical Paper
380112
T. B. Rendel
1938-01-01
Technical Paper
380113
M. J. Zucrow
1938-01-01
Technical Paper
380084
Joseph Geschelin
1938-01-01
Technical Paper
380079
C. F. Lienesch
1938-01-01
Technical Paper
380076
D. E. HAMILTON
1938-01-01
Technical Paper
380054
A. George, W. Brown
1937-01-01
Technical Paper
370180
O. C. Bridgeman, E. W. Aldrich
PURPOSE of the investigation reported in this paper was to find a suitable laboratory test method for the stability of aircraft-engine oils. Three types of laboratory methods were chosen, and data were obtained on two of them using 22 aviation oils. The two methods were (1) heating the oil with the surface exposed to the air but without aeration, and (2) heating the oil under aerating conditions. Results were compared with engine data on the same 22 oils covering 30 hr. of operation in each case at cruising power with a Pratt & Whitney Hornet engine.
1937-01-01
Technical Paper
370183
W. A. Witham
THIS paper discusses the most recent developments and best practice in both the design and manufacture of hypoid gears and axles. Due to improved machines, methods, and materials, hypoid gears now are being produced to higher standards of accuracy and precision than has heretofore been possible to produce any type of rear-axle-drive gears. To utilize such improved gears to the greatest advantage, similar advances are being made in the design and manufacture of hypoid axles. Greater rigidity of the gear mountings and the highest possible degree of precision in producing uniform axles are required, as well as proper provision for control of the tooth bearing in assembling the axle. Latest methods for producing hypoid gears are discussed, including an analysis of the Formate type of gear. A summary of the results of a number of deflection tests on various types of axles serves to illustrate various factors entering into axle design.
1937-01-01
Technical Paper
370185
Sidney Oldberg, Gilbert Way, J. B. Macauley
THE increased sensitivity of the modern high-compression engine to ignition timing, together with the use of vacuum-controlled distributor advance, has emphasized the need of an accurate spark-advance indicator for road-test use. In addition to the fact that spark advance occurring on the road cannot be predetermined in the laboratory, other causes of discrepancy between road and laboratory results may occur. An apparatus using purely electrical means for indicating spark advance on the road is described in detail as to principles involved, design, application, and operation. Curves showing spark-advance data obtained in cars with the instrument as compared to laboratory data on the same distributors are included. The use of such an instrument in obtaining octane requirements on the road is self-evident, especially when a sensitivity of up to 4 octane numbers per degree of spark advance has been observed in current-model cars.
1937-01-01
Technical Paper
370188
O. C. Bridgeman
THE problem of ring-sticking in aviation engines is unusually complicated due to the lack of standard test methods and to the difficulties in obtaining reproducible data on full-scale engines. In fact, the immediate problem is largely one of developing suitable test equipment and methods. As soon as such a method is developed, coordination of activities by different groups becomes possible, and the problem will be well on its way toward solution. In common with most lubrication problems, ring-sticking involves the inseparable trio of variables, namely, oil characteristics, engine-design factors, and operating conditions. During the early stages of aviation, ring-sticking was largely the result of the use of oils of inferior stability, such as vegetable oils and blends of these oils with mineral oils.
1937-01-01
Technical Paper
370190
C. E. Zwahl
A DETAILED report of the results obtained testing hypoid lubricants at the Chevrolet Motor Co. is presented in this paper. As a result of these tests it is announced that 182 hypoid lubricants have been put on the Chevrolet approved list. Seeking to correct an impression that only lead soap-active sulphur and lead soap-sulphur saponifiable-chlorine lubricants would be considered, the author states that other types that meet specifications also will be put on the approved list. Nine different characteristics are checked in the laboratory tests: load-carrying properties; viscosity; chemical analysis to determine the total lead, sulphur, and chlorine; oxidation; evaporation loss; non-combustible sediment; channeling; foaming; and copper-strip test. Scoring tests were conducted over a 3.8-mile speed loop in the proving ground at speeds varying from 10 to 70 m.p.h., and a new third member was used for each test of each lubricant.
1937-01-01
Technical Paper
370163
G. C. Wilson, R. A. Rose
THIS paper is a sequel of the paper, “Photo-Electric Combustion Analysis,” presented at the 1936 Semi-Annual Meeting of the Society. The indicator described in that paper has been used to study combustion of 28 fuels and chemicals. A complete table of information of the materials used as fuels is included. The results obtained from over 1000 oscillograms show a different shape of ignition-lag curve versus injection advance angle than it is ordinarily thought to have. Even though the cetane values for these 28 fuels varied from 24 to 100, they all had nearly the same ignition lag when injected near the dead-center position. This minimum value is shown to be about 1/1000 sec. The fuels of higher-cetane value reach this minimum at an earlier injection angle than do those of low-cetane value. The paper shows how a high-cetane fuel can be just as rough as a low-cetane fuel if the injection timing is too early.
1937-01-01
Technical Paper
370161
Weldon Worth
THIS paper presents the problem of engine lubrication from an installation and operation standpoint with respect to starting, warm-up, and stabilized flight. It describes the manner in which these problems are solved by the latest Materiel Division lubrication system, with its oil dilution, hopper-type oil-tank, viscosity-control valve and jacketed oil coolers. It also analyzes the radiator drag and shows the magnitude of unnecessary radiator drag that may exist if the radiator is not properly designed and installed. The paper then presents a practical design method and shows a sample design calculation for a 1000-hp. engine.
1937-01-01
Technical Paper
370173
D. P. Barnard
THIS paper represents an attempt to illustrate the values of octane-number improvements in aviation gasolines in terms of increased earning power of current-type transport airplanes when proper provisions have been made in the original designs. The procedure consists in computing the change in earning power of a gallon of gasoline when octane-number changes are reflected in altered fuel consumptions or take-off load capacities.
1937-01-01
Technical Paper
370170
C. G. A. Rosen
PRIMARILY intended as a discussion and amplification of the paper of Messrs. Boerlage and Broeze presented at the April, 1936, meeting of the American Chemical Society1, this paper reviews fuel research conducted at the San Leandro laboratory of the Caterpillar Tractor Co. and, therefore, is limited to the precombustion-chamber type of Diesel engine burning California-base fuels. The paper describes investigations of ignition quality, fuel-spray characteristics, and injection phenomena by means of a single-cylinder test unit fitted with a quartz observation window, stroboscope, timing disc and phase-changing device. A discussion of the products of incomplete combustion as influenced by compounded lubricants and ring-belt temperatures concludes the paper.
1937-01-01
Technical Paper
370150
Du Bois, Val Cronstedt
RAPID development and widespread use of aircraft fuels of high knock rating make advisable a study of the best means of utilizing these fuels for high specific power output. The response of an hypothetical aircraft-engine cylinder to changes in supercharger compression ratio (boost) and cylinder compression ratio is developed theoretically and outlined by means of charts. The explosion pressures are calculated and the resulting information used to establish a criterion of cylinder performance. Results of some cylinder calibrations on high-octane fuels show the calculated relations to be fairly well established. The effects of (1) high mean effective pressures and (2) high crankshaft speeds on the detail design of the engine are analyzed. The conclusion is reached that, in order to obtain a balanced design of minimum weight for extremely high specific output, it is advisable to use both speed and high mean effective pressures.
1937-01-01
Technical Paper
370147
W. R. Griswold
1937-01-01
Technical Paper
370143
C. G. A. Rosen
IN the investigation of combustion in Diesel engines considerable emphasis was placed upon temperatures prevailing in metal parts adjacent to the combustion-chamber envelope. In mobile-type Diesel engines these temperatures are influenced directly by design characteristics, service conditions, atmospheric temperatures, and operating schedules. Of particular importance is the combined effect of the factors upon piston temperatures and, therefore, of direct consequence to lubrication. Oxidation tests of lubricating oils for metals have demonstrated that gummy and carbonaceous products are deposited in relation to the heat gradient in the piston, particularly in the ring-belt region. The type and extent of these deposits are influenced further by the source of the crude and by the method of treatment and of finishing the lubricating-oil stock. The gummy deposits from the lubricating oil act as binders to congeal carbon and dust in the ring-grooves to produce ring-sticking.
1937-01-01
Technical Paper
370152
J. R. MacGregor
IT has been assumed generally that variations in humidity would not cause errors in knock rating when using the bracketing method. However, the preliminary test results presented indicate that this assumption is not valid for all fuels. Differences in knock ratings of over three octane numbers were found with certain combinations of test and reference fuels when the humidity was varied over the range normally experienced in knock testing. It was found that the influence of humidity on detonation is not primarily the result of changes in dry air pressure or oxygen concentration, but apparently depends on the nature of the fuel itself. The results presented are known to be affected somewhat by changes in engine adjustment and bouncing-pin setting. However, for certain fuels the error introduced by humidity changes is considerably greater than the normal experimental error with controlled humidity.
1937-01-01
Technical Paper
370151
R. F. Good
1937-01-01
Technical Paper
370129
A. L. Beall
THIS paper describes the more conventional methods of selecting an oil for use in high-output aircraft engines. It points out the weaknesses of each and justifies the selection of the engine test at high output as the most reliable criterion. The necessity for oils of better lubricating quality is established based on experience with high-output engines. A full-scale engine test of oils is urged not only as a basis for selection of an oil that will permit operation of the engine at high output but for another and equally important reason. It is equally important to determine that the oil selected will not be responsible for high maintenance costs and early and frequent replacement of parts. The paper endeavors to show that carefully conducted engine tests provide information from which oils can be selected resulting in distinct operating economies and probably improved reliability of operation.
1937-01-01
Technical Paper
370140
John M. Campbell, Wheeler G. Lovell, T. A. Boyd
IN this investigation some of the underlying principles affecting the knocking characteristics of motor fuels in service have been studied. Briefly, the experiments indicate that the relative knocking characteristics of certain cracked gasolines with respect to straight-run gasolines may be affected by the relationship among spark timing, engine speed, and mixture ratio. From the standpoint of engine design the most advantageous combination of these variables in a given engine varies according to the nature of the fuel used. It is suggested that some of the anomalous characteristics of benzol blends are the result of vaporization phenomena in the induction system, as also are certain “depreciation” effects which occasionally have been observed among straight-run gasolines containing tetraethyl lead.
1937-01-01
Technical Paper
370001
W. M. Holaday, G. T. Moore
1937-01-01
Technical Paper
370005
Neil MacCoull
1937-01-01
Technical Paper
370026
C. M. LARSON
Since the publication of the original Classification of Transmission and Rear Axle Lubricants back in 1931, evolution has seen the development of a most complicated and varied number of gear lubricant recommendations for the millions of cars now on our highways. Each year as new features are introduced, changes are made which affect gear lubricant requirements of the past. Yet nothing is done to revise car manufacturers' lubrication charts made up previously each year. A composite grouping of gear lubricants would simplify the servicing of cars on the road. At the present time, the service station attendant is required to follow with exactness lubrication charts for each and every make and model of car if he would keep the car owner out of trouble. On the other hand, the service station needs are best filled by the smallest number of grades required for proper servicing since large inventories and especially gear lubricant dispensing equipment (metered) are costly.
Viewing 16411 to 16440 of 16616