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Viewing 191071 to 191100 of 193735
1939-01-01
Technical Paper
390154
Austin M. Wolf
THE introduction of the oil filter into the lubricating system of internal-combustion engines marked a distinct advancement, Mr. Wolf states. However, he adds, due to the varying combination of working conditions, the operator who dreams that all lubrication problems are eliminated by the use of oil filters is due for a rude awakening. He continues to remark that any valuable tool can be abused if full cognizance is not taken of its possible shortcomings, and he enumerates those of the filter to form a basis of a true appraisal of its intrinsic worth. Mr. Wolf notes that conflicting opinions are heard regarding filters due to the widely different circumstances under which identical equipment is operated. In stop-and-start operations, light delivery trucks and some passenger cars never have the engine warm enough in extremely cold weather to permit functioning of the filter, he points out.
1939-01-01
Technical Paper
390157
Frank C. Mock
RECENT developments in fuel-refining processes have developed new safety fuels, and have revived general interest in the subject, Mr. Mock reports. “Safety” or fireproof aircraft fuels, he explains, must be less volatile than gasoline and should have a flash point of about 105 F, a distillation range between 375 and 475 F, and about 87 octane rating. In his paper he summarizes the program probably necessary before such fuels can be employed successfully in every-day service operations. Three methods of fuel feed are discussed: injection into the cylinder, into the intake pipes, and into the supercharger. Injection into the cylinder, he reports, has been tested on a full-scale engine on the dynamometer with some success, but it was not flown. Injection into the supercharger, he feels, is attractive because of its simplicity. Five detail problems are listed: injection equipment; changes in engine and cylinder; fuel-air metering and power control; starting; and installation.
1939-01-01
Technical Paper
390156
Ernest E. Wilson, Paul Huber
THE authors introduce their paper by outlining the various sources of noise existing in the motor car, together with some of the suppression means. Noise measurement, test methods, and the mechanism of the transmission of forces generated by the contact between the tire and the road to the body and frame are discussed. The authors state that, since these forces produce motion and deflection of the body, they are responsible for the road noise, and conclude that the proper approach to a method for suppressing road noise is through the structural design of the vehicle. They suggest, in the main, the localizing of stress to stress members, the raising of the resonant frequencies of the structure, the detuning of the suspension system, the body, and the frame, together with some isolation at selected points.
1939-01-01
Technical Paper
390159
W. S. Fisher
ALTHOUGH the torque variation of a diesel engine is somewhat greater than that of a gasoline engine, the difference is not serious at full load, Mr. Fisher explains. But, because the roughness of a diesel can become quite objectionable at no load, it is necessary, he says, to suspend the engine in such a way that its torque impulses cannot be transmitted freely to the chassis. Mr. Fisher discusses the various problems of diesel-engine installation in coaches and trucks, outlines the theory of flexible engine installation, considers the special requirements of the half-dozen auxiliary systems, and describes a number of diesel installations which have proved successful in service. The engine with which the paper is concerned is the General Motors two-stroke diesel, manufactured in 3-cyl, 4-cyl, and 6-cyl models of 82, 110, and 165 hp, respectively.
1939-01-01
Technical Paper
390161
F. F. Kishline
AN effort to bracket and clarify the controversial and widely encountered problem of varnish in engines, is the purpose of this symposium, Mr. Kishline announces. This he does largely by presenting and interpreting the experience, opinions, and questions of many anonymous SAE members and their companies on this subject. These contributions, he explains, were received from a large number of representative sources, and present a typical cross-section of this phase of lubrication. Mr. Kishline defines the offending “varnish” as a “synthetic resinous compound” precipitated by little known chemical reactions, oxidation, exposure of oil to relatively high temperatures, presence of foreign materials, or various combinations of these causes. Varnish has been blamed for a long list of engine troubles, he explains, among them sticking valves and rings, engine surges, blowby, and seizure.
1939-01-01
Technical Paper
390158
A. T. Colwell
THE trend in poppet valves during the past year, like many other advances in science, Mr. Colwell points out, has been an improvement upon existing performance, rather than an entirely new development. To effect a steady improvement in existing designs, the study of fundamentals, such as grain flow, structure, forging temperatures, coolants, and interior construction, has been resorted to, and thorough research on valve steels has been carried out, he reports. In the study of valve steel, 300 analyses were examined; intensive work was done on 20; and 4 showed definite merit, he says. Grain flows in aircraft valves made by the extrusion and gather-upset processes are compared. Results of an investigation of sodium cooling and head designs of aircraft valves by means of glass valves are reported and illustrated. Four outstanding automotive valve steels are analyzed chemically and physically - Silcrome No. 1, Silcrome XB, Silcrome X-10, and Silcrome XCR. Mr.
1939-01-01
Technical Paper
390100
B. C. Heacock
1939-01-01
Technical Paper
390160
Francis Masi
ACTUAL computation of the vibratory crankshaft stresses, although a laborious process beset with many difficulties, should offer the best chance for an intelligent evaluation of the crankshaft torsional-vibration characteristics in aircraft engines and of whether the amplitudes are dangerous or within safe limits, Mr. Masi concludes. In a discussion of the various methods used, their relative merits, and allied problems, he shows that the simple expediency of using fixed allowable amplitude limits, for certain classes of engines, determined from experience, is likely to lead to erroneous conclusions. A novel method, which has been used on numerous engines by the Naval Bureau of Aeronautics, is suggested by Mr. Masi. It consists of determining the twist of the crankshaft with the application of rated engine torque and basing the allowable vibration amplitude on the amount of the twist.
1939-01-01
Technical Paper
390101
James E. DeLong
1939-01-01
Technical Paper
390098
R. H. MAYO
1939-01-01
Technical Paper
390099
W. P. Ricart, Sandro Sirtori
1939-01-01
Technical Paper
390104
A. E. Dunstan
1939-01-01
Technical Paper
390105
J.J. BROEZE, J.O. HINZE
1939-01-01
Technical Paper
390102
H. C. Mougey
1939-01-01
Technical Paper
390103
H. A. Everett, G. H. Keller
1939-01-01
Technical Paper
390108
Oscar F. Olsen
1939-01-01
Technical Paper
390109
R. E. Gould
1939-01-01
Technical Paper
390106
Allen W. Dallas
1939-01-01
Technical Paper
390107
R. P. Lansing
1939-01-01
Technical Paper
390113
Henry Gibbins
The views expressed in this discussion are those of the speaker and do not represent necessarily the views of the War Department.
1939-01-01
Technical Paper
390111
C. T. Harris
1939-01-01
Technical Paper
390117
F. M. Young
1939-01-01
Technical Paper
390114
Thomas B. Rhines
1939-01-01
Technical Paper
390115
Richard C. Molloy, Roger W. Griswold
1939-01-01
Technical Paper
390121
E. L. Bass, C. H. Barton
IT may be necessary to compromise among the ring-sticking, sludge-forming, and corrosion properties of oil for civil aircraft engines, the authors suggest. No laboratory tests are yet able to predict the performance of an oil in an aircraft engine, they contend, and therefore, full-scale engine tests are necessary for final judgment. However, they explain, much preliminary work can be carried out in suitable small units. To illustrate the complexity of the problem the authors set forth five requirements for an aircraft-engine lubricant: 1. It must not cause ring-sticking under the full-throttle detonating conditions of take-off. 2. It must not cause ring-sticking under weak-mixture cruising conditions. 3. It must give freedom from sludging so that there is no ring-jamming, so that the oil scrapers are kept free, and so that the overhaul periods are not limited. 4. It must provide protection from cold corrosion. 5.
1939-01-01
Technical Paper
390120
H. A. Hicks, G. H. Parker
HARSHNESS in the ride of an automobile is felt as a disagreeable tremor or shock, sudden in nature as distinguished from the opposite sensation which could be described as slow, soft, and mellow, the authors state. They add that it is in the nature of a tremor having a frequency in the higher shake range and approaching the threshold of audibility. This paper is limited to analysis of the harsh vibrations which emanate from tire contact with the road, excluding the effects of the tires themselves. The authors describe methods of measuring harshness both in the laboratory and on the road, discuss car harshness in its relation to rigidity, and touch upon its relation to suspension. It is pointed out that there has been a decided trend toward more rigid construction and that, in general, harshness has increased as rigidity has been obtained. It is also noted that fore-and-aft shocks are more pronounced with independent suspension than when leaf springs are used.
1939-01-01
Technical Paper
390119
E. T. Vincent

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