Search Results

The design and development of a stratified charge engine incorporating a unique fuel injection system is described. The essential features of the combustion system and fuel systems, the engine characteristics, and the performance of a vehicle fitted with this engine are presented in detail. The engine, running on gasoline, is shown to have a thermal efficiency approaching that of some popular vehicular diesel engines, but without the smoke and noise of a diesel.

The development of the Ford Automatic Transmission Fluid from specification M2C33-B, through M2C33-D, to the new M2C33-F specification is traced. Requirements of the new specification and reasons for the change are discussed. Some experiences with the “fill-for-life” policy over the years from 1960–1967 are cited.

Dexron is the new General Motors trademark which identifies currently recommended service automatic transmission fluids. The minimum quality of these fluids is higher than that of the formerly used Type A Automatic Transmission Fluids. The new fluids will provide improved transmission operation, both initially and for extended periods of service. They may be used in servicing not only current transmission and power steering units, but also all older units for which Type A fluids were originally recommended. The fluids were developed principally to achieve longer shift-time retention and clutch plate durability. Advances were also made in respect to low temperature fluidity, antifoam quality, fluid-seal compatibility, oxidation resistance, and fluid-nylon compatability.

Base stock and additive combinations were evaluated in the Cold Cranking Simulator (CCS) to determine their effects upon the viscosity of crankcase lubricants at 0 F. The interaction of polymeric additives with base stock wax was defined, and the role of base stock V.I. in cold cranking, ascertained. These factors were found to govern optimum selection of base stocks and polymeric additives in formulating multigrade crankcase oils.

The Cold Cranking Simulator (CCS) has been shown to be a relatively inexpensive, fast, and accurate instrument for measurement of motor oil viscosity at low temperatures. ASTM cooperative work with the CCS has resulted in establishment of a Tentative Method, D 2602-67T, for motor oil viscosity at 0 F. Further data show that the method could be extended to -20 F if desired. The SAE has adopted the new Cold Cranking Simulator Method as the basis for revision of the J300 motor oil winter grade viscosity classification. This paper summarizes the efforts leading to the solution of a problem of ten years' standing.

A mechanical shearing test has been developed to evaluate the permanent viscosity loss of multigrade crankcase oils in field service. The test shows two advantages over a sonic shear test used previously. It causes polymer breakdown directionally the same as engines in the field, higher with higher viscosity oils; and test severity does not depend on the polymer type used. The new procedure provides a reliable laboratory technique for designing the used oil viscometric properties of multigrade formulations. Results from a 4 hr test predict the used oil viscosity with and without crankcase dilution, and also the extent of polymer breakdown in field service.

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.

This paper discusses a unique process developed for economic production of rigid foamed thermoplastic articles with a characteristic structure of integral solid skins and a foam core. This process is ideally suited for the manufacture of large parts because of significant savings in material, tooling, and machine costs.

A study of the correlation between engine cranking data and viscometric data at 0 F and -20 F has been made by the Coordinating Research Council. Two laboratory viscometers, the Cold-Cranking Simulator (CCS) and the Reciprocating Vijcometer (RV), have been found suitable for predicting the engine cranking performance of oils at 0 F and -20 F. Data from ASTM cooperative programs with these two instrument types agreed and both showed good correlation with data from CRC engine cranking programs conducted at 0 F and -20 F. The CCS had better repeatability than the RV at 0 F, but both viscometer types were equivalent in this respect at -20 F. Although the cone-plate viscometers gave the best correlation with engine cranking data at 0 F, they failed to provide the desired degree of precision in a second ASTM program at this same temperature; hence, no cooperative data were obtained at -20 F.

A new process for preparing urethane foam automotive trim parts is described. The new system known as integral skin foam, forms its own continuous skin which reproduces exactly the surface of the mold. Rapid mold turnover, room temperature cure, and the elimination of plastic skin can effect an overall reduction in cost per part. In items with severe undercuts, the use of pliable, elastomeric molds may be dictated in order to eliminate the juncture lines resulting from a multipart metal mold. The use of liquid urethane elastomer in such areas is described. The new system requires post-coating, and nondiscoloring urethane types for exterior as well as interior parts are also discussed.

The shaping of plastic billets below the melting point has been found to offer several advantages over the conventional melt forming processes. The most important advantages are high forming speed, improved toughness of formed parts, the capability for making very thick parts, and inexpensive tools. The processes discussed here are forging and rubber-pad forming; but these are only two of many commercially feasible solid-phase forming techniques.

Three surface characteristics: gloss, microinch finish (fiber pattern), and long term waviness, are discussed. Almost all variables have an effect on at least one of these characteristics. The main variables are molding temperature, cure time, glass type, glass content, filler type, filler content, resin, catalyst, surface mat, and post molded condition. The properties of the resin are most significant. With proper selection of resin, filler, and glass, and using proper molding conditions, laminates with excellent surface appearance can be made.

A new concept in unsaturated polyester resins now provides exceptionally smooth surfaces on molded glass fiber reinforced structures. The resins have good cure speed and contribute to excellent strength retention of molded parts at elevated temperatures. Premix compounds based on low shrink resin are well suited for injection molding because of an unusual combination of attributes. The use of these unique resins will offer reduced finishing costs for glass mat reinforced moldings and open new “appearance” applications for the versatile premix molding process.

Structural requirements for aircraft engine main fuel pumps and controls have been changing and increasing. The influence of these changing conditions on specific component parts, particularly housings and drive train elements, is reviewed. Recommendations are made for detailed specifications changes.

Glass fiber reinforced thermoplastics offer increased strength, stiffness and shape stability in automotive applications. Three processes are commercially available for merging the fibers with the plastic. One such process is described in detail and the properties resulting from its use in conjunction with inexpensive polymers processed in conventional equipment are shown to offer advantages for the automotive industry. Further improvements in understanding mechanisms of reinforcement and in materials behavior are shown to provide the basis for improvements approaching those theoretically obtainable. Such composite materials are expected to increasingly compete with metals and with more expensive thermoplastics.

Increasing demands for larger aircraft that can fly faster, farther, and higher with assurance of reaching their destinations and returning to their points of origin have far outstripped the availability of in-service experience upon which to base design reliability requirements. This paper describes test facilities that can provide this needed information by increasing component requirements beyond the known reliability criteria. The authors propose extended research and investigation into projected reliability parameters that will assume greater importance as flight ranges and altitudes are expanded for both military and civilian aircraft.

Meeting the V/L (vapor to liquid) ratios specified for aircraft engine fuel pumps actually requires the designing of two pumping mechanisms in series. The first is usually a low pressure, high cavitation performance pump. The second is an efficient high pressure pump. This report presents a procedure followed in the design of a typical aircraft engine fuel pump. Various technical parameters such as pump type, performance, efficiency, cavitation, and reliability are analyzed. Weight, envelope and cost are discussed in this paper and qualitative comparison of alternatives is presented.

It is pointed out that in attempting to evaluate devices or design alterations to minimize accident injury, there arise important questions of true injury hazard predicted by the test and of relative merit between designs, depending upon whether one employs a system test or a simplified laboratory impact procedure. These questions are illustrated first by describing some of the results of a series of accelerator tests of cadaver impact against a steering wheel and energy absorbing column assembly. A salient finding from this work is that, as a result of more favorable load distribution, the chest loading is in the range of one-half that which would be indicated by a simplified torso impact test. It is felt that in the future it will be particularly important to try to take into account in a simplified test the contribution of the shoulders to load distribution, as well as to alter the torso form to obtain more realistic dynamic deflection properties.

Aircraft turboshaft engines frequently require fast response power turbine overspeed protection. Reliability considerations dictate a direct and independent sensing of turbine speed. Severe component environmental conditions coupled with the need for high reliability and long life make design of electrical engine mounted components a design challenge. This paper cites component requirements, design problems, and solutions associated with the successful development of an electrical overspeed system for the General Electric aircraft T64 gas turbine engines.

The procedure for obtaining the performance of a thermoelectric generator from a knowledge of the materials, properties, the junction temperatures, the leg geometries, and the extraneous circuit resistance are well known. This paper deals with the reverse procedure of designing a device which will perform in an optimum fashion while delivering a predetermined voltage and current from a given input heat flux density. The design procedure is demonstrated for hypothetical 250-W generator utilizing segmented N-type PbTe (type 3N/4N)* and P-type PbTe (type 2P). The optimized performance parameters of these materials under ideal conditions are presented in tabular form. Adjustment procedures are established to account for extraneous resistance, shunt heat losses, and off-optimum design performance. The design of the converter portion of a 560-W portable multifueled generator is reviewed, and the results are compared to observed performance.