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Multifunctional or universal lubricating oils which service both gasoline and diesel engines have gained widespread commercial acceptance. Since 1970, numerous changes and additions have altered the performance tests and specifications which define the quality of these lubricants. New parameters include single cylinder and multicylinder diesel engine testing, valve train wear protection, clutch plate friction retention, extended drain interval and lubricant related fuel economy. In response to these requirements, new additive systems were developed. This paper discusses observed base oil-additive-engine test interactions and compares the performance of one of these additive systems to that of the old.

This paper covers the development of Ferrographic oil analysis techniques for the study of diesel engine wear. A brief overview of the various wear analysis techniques now commonly used in laboratory and field engine wear studies is discussed. Also included in this paper is an in depth description of the Ferrographic oil analysis techniques and the various applications of the techniques to the study of engine wear. A comparison of the commonly used wear measurement methods, Ferrography, spectroscopy and the radioactive tracer methods, and their abilities to measure wear is also discussed. A direct injection, 4-cycle, turbocharged diesel engine was used in the testing and data are presented indicating the abilities of the Ferrographic oil analysis techniques to detect changes in wear rates. The effects of operating time on engine oil and the effects of the variation of oil and coolant temperatures on engine wear is presented.

Two synthesized commercial engine oils have been developed and extensively evaluated to document a number of unique performance benefits. The benefits include significant fuel savings in heavy-duty diesel truck engines, excellent low temperature fluidity, engine cleanliness and antiwear protection, extended drain capability, and good oil economy. The results of standard and double-length laboratory engine tests, chassis rolls tests and confirming field tests are discussed in the paper.

Thirteen new 1965 buses having GM 6V-71 diesel engines were put on various oil/filter change periods from 6000/6000 to 25000/25000 miles, and operated in normal passenger service for seven years (1966-1973). Crankcase oil was tested periodically, and oil filters were examined after scheduled removal. Maintenance and operation records were kept. Finally, at the overhaul point some engine parts were examined. The optimum oil/filter change period was judged to be 25000/12500 miles, in conjunction with field testing for solids load, water and dilution. Correlations and oil test data, suitable for reference, are given.

The large variation in salt spray performance of painted steels can be largely attributed to carbonaceous residues on steel surfaces. It has been shown that failure in the 240 hour salt spray test correlates strongly with high surface carbon. The adverse effect of surface carbon highlights the need for stringent control of steel surface cleanliness and for paint primers insensitive to alkaline undercutting. Corrosion tests have been developed which produce service-like failures more rapidly than are obtained with salt spray, by incorporating the use of freeze cycles, surface dust and high test temperature.

An entirely new concept for applying organic films to steel surfaces has been developed and has been in production for two years. This technique relies on chemical attack of the metal substrate and use of the reaction products to deposit a latex polymer which forms a continuous film on curing. The method for application of films via autodeposition requires immersion process steps although spray stages are used in cleaning and rinsing.

The quality of the adhesion of paint to hot-dipped galvanized steel under severe deformation increases as the fraction of grains with the (0001) plane approximately parallel to the surface increases. Paint adhesion is improved by a small grain size of the zinc and by a rolling operation. The best paint adhesion has been observed on samples with a small grain size of zinc, very highly oriented with (0001) planes parallel to the surface. The fraction of grains exhibiting orientations approximating (0001) was determined by X-ray diffraction analysis and by a newly-developed etching procedure. The effect of grain orientation on paint adhesion is attributed largely to the mechanism of deformation of zinc although the chemical properties of zinc are also a function of the crystal face exposed at the surface.

Zinc phosphated steels representing a wide range of salt spray performance were analyzed for coating weight, composition, X-ray structure, morphology and porosity. Of these factors, apparent coating porosity was the only characteristic that consistently correlated with salt spray performance. An electrochemical test has been developed which measures relative porosity values accurately, rapidly, and directly on zinc phosphated steels. This technique has been employed to show that the residual carbonaceous materials tightly bound to the surface of commerical steels need to produce porosity levels of only a few percent in order to drastically reduce the effectiveness of zinc phosphate coatings as a paint base.

Cathodic electrodeposition was successfully introduced to the general U.S. industry in 1971. Several properties specific to the automotive industry were required before it could be introduced to the automotive industry in 1976. Cathodic electrodeposition is capable of producing superior corrosion resistance over steel and other substrates. For the automotive industry, additional characteristics of high throw-power, lower curing schedules, long term stability, and others were necessary for this paint to be satisfactory to this industry. Many equipment requirements of Cathodic paint are similar or identical to those of Anodic paint, but there are also some specific differences. Operation of Cathodic systems are also similar in many respects to Anodic systems but control parameters such as pH, MEQ, voltage, and conductivity are different. These differences in the equipment and control of Cathodic systems are related to characteristics of Cathodic chemistry.

Polymeric mineral oil additives are exposed to mechanical and thermo-oxidative degradation processes in the engine. For long lasting efficiency, they must show the highest possible stability to such attacks. The degradation processes are evident from and distinguishable by the molecular weight distribution of the polymer which can be measured with great accuracy by gel permeation chromatography (GPC), even for used oils. Results of such measurements are given for various types of VI improvers (polyalkyl methacrylates, ethylene-propylene copolymers and hydrogenated styrene-diene block copolymers) after exposure to Diesel and Otto engines. The influence of mechanical and thermo-oxidative degradation is discussed by means of model calculations. Comparative viscosity data elucidate the picture obtained from the distribution measurements.

With the advent of high speed computers, dynamic simulation of an automobile body has become a reality. The present work will discuss methods to develop a body model of manageable size which will give good correlation with tests and can also be used as a practical design tool. The basic approach is to model each component as a separate entity and then combine the components into a system model, a “Building Block Approach.” Finite element mesh considerations and modeling difficulties are discussed. An example of a vehicle body is presented to illustrate the approach.

Low-frequency interior noise in the automobile passenger compartment can be significantly affected by the vibration behavior of the body panels which surround the enclosed cavity. This paper reviews a finite element method for computing panel-excited interior noise and outlines an approach for identifying potentially noisy panels adjacent to the passenger compartment. To illustrate the potential of the analytical method, it is applied to a production automobile. A structural modification suggested by the procedure is shown to significantly reduce the low-frequency interior noise to which the occupant is exposed. Experimental verification of the method is presented.

A formulation is presented for the static and transient analysis of sheet metal structures involving very large displacements and rotations and elastoplastic material behavior. The geometrical nonlinearity can be treated by the decomposition of the element displacements into rigid body and deformation displacements. The elastoplastic formulation is based on the Mises yield criterion with isotropic strain hardening. The equations of motion are integrated by either the explicit or implicit schemes. Elements employed include the spring, three-dimensional beam, and plate element. Internal force or moment releases and rigid links are provided for beams.

A cost-effective early indicator of frontal barrier performance relative to government and corporate goals has been provided by half-scale metal models. These models provide direct indications of steering column kinematics and performance of specific components with respect to the windshield intrusion zone. Some indications of fuel system integrity and windshield retention evaluations have been inferred from half-scale model barrier tests. Model tests have provided early standard barrier data on vehicle crush modes and distances, barrier loads, and deceleration rates, in addition to generating data beyond what is available in standard barrier tests.

Vehicle energy in head-on or rear-end collisions is mainly absorbed by the front or rear longitudinal members. This paper describes the methods of calculation of crush load and the energy absorbed during the static and dynamic crush of the sheet metal members with closed-hat section together with attached flanges or walls. Calculated results were compared with experiments including full-size automobile collisions. It is expected that the analysis considering the strain rate sensitivity will provide more accurate design information for improved automobile crash-worthiness.

This paper summarizes the correlations obtained between Cold Cranking Simulator viscosities and gasoline and diesel engine cranking data on 17 commercial engine oils. These engine oils include the new synthetic 5W/20 oils. The ability of an oil pumpability bench test to predict the pumpability properties of these 17 oils in a gasoline engine is also presented. The Cold Cranking Simulator Viscosities measured at temperatures from -40°F (-40°C) to 32°F (0°C) were studied to determine the necessity of measuring CCS viscosities of each “W” graded oil at its minimum expected use temperature.

Investigations using 4 monograde and 3 multigrade engine oils were performed by cold cranking an automotive engine to determine whether or not there is friction reduction due to the pseudoplastic behaviour of the multigrade engine oils. A comparison of the oils using viscometers indicated the viscometers ability to predict the “engine viscosities” over a temperature and shear rate range. Furthermore, this work determined whether results of viscometric measurements could be confirmed with the test engine. An answer was found to the question of the amount of hydrodynamic friction encountered when starting an automotive engine at low temperatures.

This paper illustrates how experimental design techniques can be employed to obtain an accurate assessment of multigrade Heavy Duty (HD) performance in the field. Compared to monograde (SAE 40) oil, the use of SAE 15W/40 oil was found to improve vehicle fuel mileage (MPG) as well as oil economy (MPQ). The demonstration, conducted in two groups of 10 city buses each in regular service, was structured to dampen out the effect of numerous incidental variables. Statistical data analysis indicate a “most probable” improvement in fuel mileage of 2.7% as well as a 47% increase on multigraded oil economy.

Thermosetting liquid urethanes processed by reaction injection molding (RIM) can be reinforced with glass fibers. Special considerations of both the materials and the process system elements are required due to the characteristics of the reinforcement. Typically, slurries are prepared with milled glass fibers and one or both of the liquid urethane components. Then the urethane components are combined with mechanical and/or impingement mixing and injected into a mold. The resulting composites show increased stiffness and reduced thermal expansion due to the glass fiber reinforcement. These new material systems are expected to be used in many applications requiring good dimensional stability over a wide temperature range.

Sheet molding compound (SMC) has been used for functional or fascia automotive parts such as front and rear panels for several years. When properly formulated, processed, and molded, SMC has a potentially substantial role in the manufacture of more structurally demanding automotive parts. Through variations in the materials, equipment and processing techniques, different types of SMC can be produced. These are random fiber SMC (SMC-R); continuous fiber SMC (SMC-C); and directional fiber SMC (SMC-D). Representative formulations show how static mechanical properties are dependent upon glass content, glass orientation, and on the test temperature. Based on equivalent performance, these systems are lighter in weight than steel and are generally less costly, on a material basis, than aluminum.