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The EPA Heavy Truck Driveby Noise test is used to regulate trucks over 10,000 pounds GVW. The EPA test procedure is based on SAE J366. The EPA/J366 procedure is used both as a regulatory compliance tool and as a development tool. When the test procedure is used as a development tool, the goal is to determine the most cost effective means of meeting the legal requirement. Since J366 was not intended as a development tool, it can be difficult or misleading to use it to make decisions on product configuration. In order to use J366 successfully in vehicle or engine development, one must understand and properly account for the inherent variability of the J366 driveby test procedure. This paper examines both the extent and some of the sources of J366 driveby test variability. Strategies are proposed to ensure the proper interpretation of test results. Several repeat tests are required to accurately determine a small change in driveby noise level.

High Velocity Oxygen Fuel sprayed face coatings have shown great promise for piston rings used for High Power Density Diesel Engines. Various coatings have been tested on both wear test rigs and in engines. A highly dense HVOF cermet coating was developed with reasonable crack resistance during service. The HVOF coated piston rings wore three to six times lower than chrome plating. Cylinder liner (counter face) wear was found to be one to three times higher than chrome. However, engine oil consumption and blow by were within normal values. The HVOF coating is considered to be an excellent replacement for chrome plating. The coating process is more environmentally friendly than the chrome plating process. Also, the coating has potentially lower or equivalent production cost when compared to chrome.

This paper examines the feasibility of using the boundary element method (BEM) and the Rayleigh integral to assess the sound radiation from engine components such as oil pans. Two oil pans, one cast aluminum and the other stamped steel, are used in the study. All numerical results are compared to running engine data obtained for each of these oil pans on a Cummins engine. Measured running-engine surface velocity data are used as input to the BEM calculations. The BEM models of the oil pains are baffled in various ways to determine the feasibility of analyzing the sound radiated from the oil pan in isolation of the engine. Two baffling conditions are considered: an infinite baffle in which the edge of the oil pan are attached to an infinite, flat surface; and a closed baffle in which the edge of the oil pan is sealed with a rigid structure. It is shown that either of these methods gives satisfactory results when compared to experiment.

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.

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.