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PREIGNITION is defined by Mr. Winch as the initiation of a flame front by some means other than the spark discharge at some point in the combustion chamber prior to the arrival of the normal flameat that point. He believes that wild ping is actually a combination of preignition and knock. His study of both 1952 and 1953 cars indicates that preignition has become a very serious problem. Moreover, in some cases, the problem was found to be more serious in the 1953 car of a particular make than in the 1952 model. In these studies preignition and wild ping were identified by a technique that makes use of the spark plug as an ionization gap.

The basic theory of an expansion chamber assumes an infinite straight outlet tube and no reflected waves; neither of these conditions exist in practice since a vehicle's hydraulic system contains a finite length of tubing with bends, constrictions, and valves. These complicating factors make the reduction of fluidborne noise a system design problem rather than only a component design problem. Despite these problems and packaging problems which prevented the optimization of the filter design, very significant operator ear noise reduction was achieved by addition of the expansion chamber in the hydraulic system of a certain prototype tractor with cab.

Development of the Army's new Arctic Engine Oil (OEA) Specification MIL-L-46167 required numerous laboratory and field engine evaluations as well as large scale laboratory and field testing of these new lubricants in military hydraulic and power transmission fluid systems (HPTF). An earlier SAE paper emphasized the engine performance aspects of these synthetic oils, and now the current paper points up and emphasizes the significant performance areas in military HPTF systems. The new oils function well as year-round lubricants in Army HPTF systems including: automatic and power-shift transmissions, power steering units, hydraulic winches, pumps, and mechanical and construction equipment hydraulic systems. It appears that the new synthetic arctic engine oils have significant potential military applications in HPTF systems outside arctic regions as well as inside the arctic. Problem areas are discussed and a recommendation is advanced for the development of a truly “universal” HPTF.

Measurements of pump fluidborne noise can be influenced to a considerable degree by the effects of standing waves and volume compressibility within the discharge line. In the absence of a standard procedure for handling these effects, it is difficult to make comparisons of pump fluidborne noise data and to use such data in low noise system design. This paper discusses the influence of discharge line parameters on fluidborne noise measurements and proposes a simplified test procedure for determining the inherent fluidborne noise level of a pump. Results from experimental and analytical investigations are described.

This paper presents several techniques used to define quantitatively the problem of excessive noise through engine structural vibration. These techniques include both operating engine tests and bench tests. In addition, analytical techniques are shown which give a better understanding of how the critical components within the engine cause this vibration. Through the use of analytical and experimental techniques, examples illustrate practical solutions for diesel engine noise reduction.

This paper describes an approach to predict the dynamic behaviour and the radiating noise of the diesel engine structure. Nowadays, all diesel engine designers have to pay their prime attentions to engine specifications so as to meet more stringent future governmental control standards both in exhaust emissions and noise. For this purpose, it is absolutely necessary to establish criteria that can predict in the early stage of design the vibration modes and their noise levels inherent in individual engine structures so that the most cost-effective engine designs from the noise point of view can be screened out. Some basic experimental results obtained by using a simple structure model to develop such design criteria are described in this paper. Natural frequencies and the vibration modes of the structure are calculated by finite element method and the results are ascertained both by accelerometers and holography.

A method of determining the contributions to noise radiated by a diesel engine using idealization and response analysis is described. An idealization of the engine surface as a set of flat plates is used to calculate radiation efficiency from physical properties and edge constraints of each plate, and the velocity response of the engine surface is measured using accelerometers. This data is used in a simple acoustical power relationship to determine 1/3 octave sound pressure levels under free field conditions for the engine and individual noise sources on the engine. The theory is discussed and an example of the application of the method is given, and compared briefly with the more traditional noise source identification technique of lead cladding.

Load-sensitive hydraulic control systems have demonstrated new potential high efficiency levels. Mobile equipment designs which widely utilize open and closed center circuits are being adapted to total centralized load-responsive stand-by systems to curtail fuel consumption and operating costs. This paper outlines previous art in steering systems and highlights the design concepts required to adapt the steering function to load sensitive variable flow-pressure circuitry. Since the steering function power demands are normally low for corrective maneuvers, it is ideally suited to the environment of a central load-sensitive system. The general concept of a load-sensing steering valve and its relative design role to the other system components will be developed, emphasizing standard meter-in load-sensing technology. The possible new “feathered” and “absolute” type systems are introduced.

The fact that temperature can affect the performance of friction material has long been recognized, and many studies of the phenomena have been made. For the most part, results have been contradictory and indicate a complex relationship between temperature and other variables that constitute the conditions of use. This paper offers a report on the continuing effort to establish the extent of change produced and the mechanism by which such change is effected. Data are presented on SAE #2 machine test of three friction materials in three oils controlled at varying temperature level. How the temperature effects can be further modified by pressure or power loadings are also demonstrated. In addition, study of friction hysteresis with temperature-performance at temperature as affected by previous history - is included. Theories are proposed to explain trends noted in the data.

Agricultural electronics (Agrionics) provide vital information and control for the modern farmer to improve his decision-making capabilities. The large and complex equipment utilized in modern day agriculture demands monitoring equipment. Guesswork adjustments on machinery are no longer acceptable with the competitive markets and environmental concerns in agriculture today. With increased interest in fuel conservation, ecology, operator environment, and efficiency of machine operation, monitoring is rapidly growing from a luxury to a necessity. The result is that all of us who must eventually consume the end result of agriculture - food - will benefit.

Many different methods are now being utilized in aiding engineers to determine significant parameters for designing tractor components. The technique discussed in this paper utilizes time-lapse photography in a time-and-motion study of industrial tractors. This time-lapse method makes the determination of vehicle parameters easier and more reliable. Vehicle parameters determined by this method are productivity, cycle times, operating procedures, operator movements and machine lost time. Every engineer would like more information in designing a final product. At present, this information is acquired by marketing feedback, service reports or testing the product. In most cases the engineer is still left grasping for more information regarding how this machine is used and what types of operations does it really go through. Such information would be very useful in product life determinations now that increased emphasis is being placed on product reliability in the courts.

The purpose of this paper is to describe a system of selection for technical leadership which has been developed in the UK's Royal Electrical and Mechanical Engineer Corps. It has been refined over the years into an effective method of selecting young men with qualities which have taken them to responsible positions in technical management.

A self propelled vehicle has been developed which automatically forms a stack of hay bales with interlocking tiers. The stacks made with this vehicle show significant improvements in stability and appearance as well as providing a hay stack which can be mechanically loaded on transport trucks. Introduction of this vehicle will greatly influence the future trends in baled hay handling in the far western part of the United States.

Materials and energy are the lifeblood of our industrialized economy. Annually the United States uses over 4 billion tons of mineral materials and fuels. Domestic processed materials of mineral origin and energy are valued at more than $210 billion annually, derived largely from domestic sources, supplemented by imports. We now find increasing competition in world markets when it comes to acquiring needed raw materials, while at the same time we also find strenuous competition in selling many manufactured articles. Increased efficiency in our mining, minerals, metal, mineral reclamation, energy, and transportation industries requires accelerated development of new and improved technology.

To effectively utilize larger trucks (85 ton and up), open-pit mines and quarries need a larger front-end loader with high reliability and performance. This paper describes the design approach and tests carried out to design 21 cubic yard 580 PAY® loader to meet these requirements. Long fatigue life of structures was obtained by use of full penetration welds. New concept for power control was designed to effectively distribute power between hydraulics and drive train. Spring applied - pressure released brakes were designed into the axle. Tests were carried out in our laboratory and proving grounds to determine performance and reliability.

A five-vehicle, 64 000-km test with 7.45 litre V-8 engines was conducted to determine if synthetic engine oils provided performance sufficiently superior to that of conventional engine oils to permit longer oil change intervals. The results show better performance in two areas of deposit control; inferior performance with respect to wear protection; and essentially equivalent performance in the areas of fuel and oil economies. Based on these data, it was concluded that synthetic engine oils do not provide the necessary performance required to safely recommend their use for extended oil change intervals. In addition, a cost analysis shows that the use of synthetic engine oils, even at a change interval of 32 000 km, will essentially double the customers' cost compared with conventional engine oils at GM's current 12 000-km change interval.

The terms abrasion and erosion mean different things to various people. Moreover, there are many devices for measuring the response of materials to abrasive wear. The results from such machines do not consistently agree with those of the others because variables that differ in kind and amount are involved. Classification areas that help define the variables are an aid to the selection and application of laboratory and service tests. To three categories previously proposed by the author, and widely adopted, four others are now added for completeness and in hopes that misapplication of the terminology will be minimized. These are described and in several cases linked to better known laboratory tests.

A direct as well as an indirect injection system have been studied in regard to noise, exhaust emissions and fuel consumption on a V-10 diesel engine. The dependency of the sound pressure levels on engine speed, engine load and injection timing is described for both combustion systems. The noise reduction achieved by optimisation of injection timing is shown in relation to the respective changes in exhaust and smoke emission output and fuel consumption.

The need for clear definition of accuracy performance and operating criteria for Load Indicating Systems has been voiced by crane operators, crane manufacturers, and legislative agencies. A thorough study of the existing Recommended Practice was undertaken with the specific goal to upgrade J-376 to permit greater understanding of the minimum performance requirements of Load Indicating Systems.