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The objective of the project was to equalize the coolant and component temperatures throughout the engine and to eliminate any localized “hot spots”. A designed experiment was conducted to determine the effect of various parameters on the distribution of coolant flow through the internal coolant passage system of a NASCAR Winston Cup racing engine. The recommended configuration which includes internal passage restrictors and external coolant lines considerably reduced the temperature differential throughout the engine and significantly reduced the temperatures of localized “hot spots”. On track testing confirmed the results gathered during the dynamometer testing. The analysis of several engines upon the completion of actual competition validated the effectiveness of the recommended coolant system configuration.

For eight years, in conjunction with the General Motors Corporation, a graduate program in motorsports research and education was developed at North Carolina State University. This program sought to favorably impact the General Motors racing program with the application of advanced technology and to use motorsports as a vehicle for training engineering students. Faculty and students were involved with NASCAR Winston Cup, Indy Car, and NHRA Pro-Stock drag racing. This paper details the accomplishments of the program.

An experimental method was developed to dynamically measure rigid-body camshaft torsional vibrations in a high speed internal combustion engine. A mathematical model of the system was also created which required an accurate dynamic model of the entire valvetrain to predict the forcing function. Techniques for limiting the vibration were also implemented and tested. While attempting to correlate the experimental and theoretical results, it was discovered that the rubber timing belt exhibits viscoelastic behavior. The system stiffness and damping coefficients are frequency dependent. A system identification was required to accurately determine these parameters. No distinct relation between camshaft torsional vibrations and valve response was determined for the system studied. However, significant vibration reduction was achieved with a camshaft damper and an inertia addition to the camshaft.