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Data link interfaces are a very important part of the heavy duty vehicle industry; sharing information between subsystems is vital. SAE Recommended Practices J1708, J1587 and J1922 were developed to provide standards for proprietary communications, general information sharing, diagnostic definition and early powertrain controls. The industry realized, however, that these standards would not accomplish the ultimate goal-that of a high speed control and communications network. The development of more capable serial data communications for the heavy duty vehicle industry was prompted by the following: the desire of component suppliers to integrate subsystems for improved performance; the advancement of technology; customer expectations; and government regulations.

Corrosive wear of non-ferrous engine components by lubricants is a concern of all major heavy duty diesel engine manufacturers since warranty on key engine components has been extended to 500,000 miles. Several commercial lubricants have been linked to premature cam and rod bearing failures induced by corrosion in certain fleets. Although the overall failure rate is low, specific fleets have experienced significantly higher failure rates due to the lubricants used. These failures usually occur at high mileages but less than 500,000 miles. This kind of slow corrosion easily escapes detection of engine tests contained in current oil specifications, and it represents a serious issue in long term warranty cost to diesel engine manufacturers. A comprehensive fleet database has been established to identify the most corrosive lubricants. These lubricants have served as reference oils to develop a corrosion bench test.

Vehicle mission simulation is one component of a system designed to optimize selection and operation of on-highway vehicles. The focus of vehicle mission simulation is on equipment specification. It can predict the physical and financial performance of equipment alternatives, identify opportunities and correct problems before a truck is purchased.

This paper documents the successful operation of a modified Cummins T46 turbocharger with a ceramic rotor. This turbocharger is modified to incorporate a 4.6 inch diameter ceramic turbine rotor (pressureless sintered silicon nitride) on the hot end. These results document the most complete ceramic turbine rotor performance map, for a large ceramic turbocharger rotor, available to date.

The ongoing need for improved fuel economy, longer engine life, lower emissions, and in some cases, increased power output makes lower charge air temperatures more desirable. In 1983, Cummins introduced the new BCIV engine at 400 H.P. (298 KW) with “Optimized Aftercooling”, and is now introducing this concept to its remaining 10 and 14 Litre premium diesel engines. This Tuned Low Flow Cooling design provides many advantages when compared to the other alternatives studied, which included air-to-air and systems incorporating two radiators. The selection process considered performance, durability, fuel economy, emissions, noise, investment, and total vehicle installed cost. Computer simulations and vehicle tests were used to determine performance for each charge air cooling alternative. The simulations were used to guide prototype development and the selection of production hardware.

This paper discusses the various process changes, engine improvements, and equipment evolution that have contributed to significant increases in test productivity for heavy duty engines over the past several years. It deals with the development of short test cycles, methods of diagnosing operating problems, methods of maintaining test accuracy and discusses systems for minimizing test equipment down time. Finally it presents historical overview of the changes as they occurred at Cummins Engine Company and how performance improved over that transition period.

The advantages and disadvantages for the current oil consumption measurement systems, including the real-time oil consumption measurement and traditional weight methods, are reviewed. Based on the review, the Smart Oil Consumption Measuring System developed by Cummins Engine Co. in an effort to resolve some of the disadvantages of the systems developed earlier, especially compared to the Gravity Fed oil consumption measurement system, will be discussed. In addition, the uncertainty analysis of the Smart Oil Consumption Measuring System will also be briefly discussed here. The Smart Oil Consumption Measuring System has proven to be an effective tool to measure the oil consumption at almost any engine test conditions, including the steady and cyclic tests in a shorter time than most of traditional oil consumption measurement systems.