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Gearing load spectra data collected under actual working conditions help a designer predict the fatigue life of power train components. Considerable time was required in the past to collect and reduce these data to a form suitable for design use. A vehicle mounted instrumentation system consisting of a strain gaged shaft, a shaft encoder-slip ring assembly, and an amplitude distribution analyzer, was developed which performs load measurements. At the test's conclusion, it provides a spectrum analysis in printed histogram form.

THIS paper presents results which will answer many of the problems facing an engine manufacturer in the selection of the most suitable types and sizes of superchargers to use with a line of engines. Although performance curves of production model diesels are available, decisions are still needed in choosing peak supercharging pressures, drive means, and size and effectiveness of intercoolers, if any. The author describes the use of a typical model to determine response to variation in intake and exhaust conditions, resulting in data which will assist in evaluating engine potentials with any system of supercharging. Thus, supercharger selection for a particular line of engines is aided by knowledge of engine characteristics as a second-stage compressor.

THIS paper points out that the advantages of using light, nonadditive oils are often sacrificed because of lack of fundamental knowledge about gear-scoring problems. Most formulas that have been developed to determine the scoring resistance have been totally empirical and have proved inadequate for stringent design requirements. The author discusses the excellent correlation that exists between scoring test results and a hypothesis on the failure of straight mineral oils. This correlation also encompasses the test results of ball and roller scoring test machines, showing the probable universal application of the hypothesis. The method of approach to the scoring problem of gears as discussed in this paper is a fundamental one, which combines the factors affecting the conversion of frictional energy into surface temperature with gear tooth geometry, stiffness, and surface finish, and points a way to design gears of higher scoring resistance.

Chromatographic analysis of diesel exhaust indicates a number of low molecular weight hydrocarbons, below C6. Using reactivity index as a criterion, much of the diesel exhaust reactivity can be attributed to ethylene and propylene caused by the thermal decomposition of the fuel. Hydrocarbons in the C4-C7 range, including high relative reactivity olefins, are generally low in volume concentration and therefore contribute little to the overall exhaust reactivity. Hydrocarbons, in terms of parts per million carbon above C7 are low in present diesel engine designs, so individual volume concentrations are generally fractional parts per million. Reactivity per horsepower-hour from diesel engine exhaust is less than that from the one small industrial gasoline engine tested by the heavy-duty truck diesel engine cycle.

HIGH load-carrying ability and fatigue strength, good embeddabiltty and conformability, and resistance to wear, seizure, and corrosion are factors that sold them on aluminum for bearings, the authors report. Bonded steel backing, they say, makes aluminum bearings even better. Retaining aluminum's good properties, it improves some of its bad points and gives such advantages as: Reduced bearing clearances, compared with those used with solid-aluminum bearings. No life limit in operation below 5000 psi fatigue stress value. Less sensitivity to high oil temperatures. Negligible wear (after 29,000 hr in one test). Simpler and less expensive bearing-locating designs. Special excellence for high-load, high-speed applications.

SETTING ratings for diesel engines takes laboratory testing and field experience for critical parameters such as smoke, piston temperature, and exhaust temperature. Rating is based upon theoretical considerations, plus the approval of the engine itself. Factors in rating considerations include a knowledge of the application of the engine, and whether its use is to be intermittent or continuous. Ratings by the manufacturer are not always accepted by the engine user, however. The user will run the engine at the load most profitable for him, which may be above or below that recommended by the manufacturer.

A single-shaft, simple-cycle gas turbine engine has been developed to power 200 kw alternators for standby power and for applications where heat is needed. The engine was designed to be sold and serviced by distributors of earthmoving and industrial machinery. Where feasible, design practices of industrial piston engine powered generator sets were incorporated to facilitate installations of combinations of engine types, and to limit novel and unfamiliar features of the basic turbine engine to those that were considered essential. Individual components and complete engines, initially developed by a research group, have been subjected to a wide variety of laboratory tests to measure performance and develop reliability.

Two high specific output diesel engines designed for the Military -- the LVDS-1100 and LDS-750 engines, which are of V-8 and 5-cyl in-line configuration, respectively -- were developed by Caterpillar Tractor Co. under contract with U.S. Army Tank Automotive Center at Detroit Arsenal. This paper covers the development work, also sponsored by ATAC, required to adapt these engines for operation using regular grade gasoline in addition to the diesel and CIE fuels for which they were originally designed. Test techniques used, a description of some interesting combustion systems tried, and data obtained with the selected arrangement are included. The engine has excellent performance and starting characteristics with any of the three fuels.

A very high output (VHO), compression ignition engine family has been designed for the Military by Caterpillar Tractor Co., under contract with the U.S. Army Tank-Automotive Center, Detroit Arsenal. The engines in this family have maximum parts interchangeability and feature a multifuel combustion system. The first model, the LVMS1050, has been built and tested. This engine develops 960 bhp, weighs 2.5 lb per hp, and produces 29.5 hp per cu ft of volume. This paper discusses the family design and LVMS1050 development.

Diesel engine exhaust emission characteristics vary considerably with the overall design of the combustion and fuel injection systems. Emission measurements were made on total hydrocarbons, nitrogen oxides, carbon monoxide, carbon dioxide, and smoke. The hydrocarbon measurements of the precombustion chamber engine are considerably lower than the direct injection engine. Less than five pounds of total hydrocarbons per 1000 gal of fuel are produced at rated conditions by all precombustion chamber engines studied. Precombustion chamber engines produce smaller quantities of the oxides of nitrogen when compared to direct injection engines. All diesels produced low carbon monoxide emissions. A novel technique for qualitative and quantitative evaluation of diesel exhaust odors is introduced. Exhaust odor intensity from the precombustion chamber engine is much less than that from the direct injection engine.

A new 2-ring piston package has been developed which has proven successful in internal combustion engines. The need for a compact piston arrangement is discussed along with the steps followed to arrive at excellent oil economy. The paper presents other advantages related to cost savings, lower wear, and reduced engine friction. The paper discusses applications of the compact piston package along with its advantages in designing compact engines.

A system has been developed that provides real-time measurement of heavy-duty diesel engine particulates emitted during the EPA transient emission test cycle. This is accomplished by measuring the opacity of the exhaust/air mixture in an EPA type dilution tunnel with a light extinction opacity meter. Simultaneously, the temperature in the dilution tunnel is measured, and the ratio of the dilution tunnel temperature to a standard temperature is used to correct the opacity signal to standard conditions. The outstanding features of the system are that it produces a continuous record of when particulates were generated during the 20-minute transient cycle and that particulate cycle results are available immediately upon completion of the transient cycle without the requirement of conditioning and weighing filters. Results to date indicate correlation of the opacity-particulate monitor measured particulates to gravimetrically determined particulates to be within 10% for specific engines.

A cooperative research program has been completed evaluating the impact of fuel composition (volatility, aromatics and sulfur) on the combustion and emissions performance of a Caterpillar 3406B turbo-charged diesel engine, which is representative of diesel truck engines of the late 1980s. Tests included both steady-state and transient operation measuring regulated and unregulated emissions. The fuel set was blended using only commercially available refinery stocks typical of those which could be considered for use in distillate fuel. The compositions of the blends were selected so that direct measurements of the individual effects of 10% and 90% distillation temperatures, aromatic content, and sulfur content could be made independently. Engine combustion performance data indicated that all fuels operated satisfactorily; aromatic content was as high as 50% and cetane number as low as 39. Further, the cetane number did not predict the engine measured ignition delay in this program.

This Paper: 1. Shows that the present spherical rod end manufacturer's rotational tests, which are intended to select the best bearing material, do not necessarily select the best materials for the push/pull linkage requirements of earthmoving machinery. 2. Emphasizes the need to perform push/pull comparative testing as defined in SAE J1367 on spherical rod ends to determine acceptable materials for earthmoving equipment application. This test is in contrast to rotational testing presently being performed by spherical rod end manufacturers.

THE CATERPILLAR FOLDED CORE RADIATOR IS A NEW RADIATOR FOR VEHICLES AND STATIONARY ENGINE APPLICATIONS. THE MAJOR OBJECTIVES OF THIS DESIGN ARE TO GIVE THE USER AN INCREASED VALUE COOLING SYSTEM BY REDUCING RADIATOR REPAIR COSTS AND IMPROVING AIR-SIDE PLUGGING RESISTANCE. AS WELL AS PROVIDE THE VEHICLE DESIGNER WITH INCREASED APPLICATION DESIGN FLEXIBILITY. THIS IS TO BE ACCOMPLISHED WHILE MAINTAINING PERFORMANCE AND LIFE GOALS ASSOCIATED WITH THE CONVENTIONAL RADIATOR. THE FOLDED CORE IS A MODULAR DESIGN HAVING THE MODULES INSTALLED AT AN ANGLE TO THE FAN AIR STREAM RESULTING IN THE FOLDED APPEARANCE. COMMON MODULE SIZES ARE USED ACROSS THE MANY RADIATOR APPLICATIONS REDUCING INVENTORY REQUIREMENTS AT THE ASSEMBLY PLANT AND PARTS DEPOTS AND INCREASING INDIVIDUAL MODULE PRODUCTION VOLUME. THIS RADIATOR DESIGN IS REVIEWED FROM CONCEPT TO PRODUCTION.