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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.

Optimal design of high-speed valve trains requires the use of an accurate analytical model. While the governing differential equations are important, the coefficients (or parameters) used in these equations are equally as important. Since many of the parameters used in valve train models are difficult to measure directly, parameter identification based on experimental data is required to assure model accuracy. This paper addresses the parameter identification problem for a valve train model, formulating a scalar cost function which represents the difference in measured and predicted system response. Minimization of this cost function yields the 10 unknown system parameters. As the cost function has many local minima, a global optimization scheme must be employed.

A method for constructing a cam profile for high performance engines was developed by breaking the cam profile into ten separate polynomial events, defined by boundary conditions at both ends of each event. The separate events allowed the cam profile to meet several kinematic constraints and gave the profile fifteen degrees of freedom for optimization. The degree position of the camshaft was ‘locally nondimensionalized’ with respect to each event in order to simplify the solution of polynomial coefficients. In addition, the cam profile was made ‘mathematically symmetric,’ applying the coefficient solutions from the opening side to the closing side.

Balancing of the crankshaft to minimize bearing loads is a critical concern in the design of multicylinder engines, especially high-speed racing engines. In this paper a numerical model is developed for the crankshaft-connecting rod-piston assembly that considers reciprocating forces as well as gas pressure forces. The model is used in an optimization scheme to design crankshaft counterweights which minimize main bearing forces. A V-8 NASCAR engine is analyzed. The results indicate reductions in average bearing force of as much as 73% while peak force is reduced as much as 41%.

One of the primary objectives of building an automotive engine is to produce sufficient power throughout its most common operating range. The objective of this study is to determine how maximum engine speed may be increased through rocker arm modification. Current knowledge suggests that there are two primary factors in the design of rocker arms that will effect the engine's operating speed: the mass moment of inertia and the stiffness. Experimental and computational methods were used to investigate the influence of these two factors on valve train performance. The ANSYS Finite Element package Design Optimization Routine was used to optimize the design of a typical Chevrolet NASCAR rocker arm and one used in the Buick V6 Indy Engine. Also investigated was the use of various materials for rocker arm construction.

One of the major tendencies in engine design is to increase operating speed. In order to increase engine speed, the importance of valve train design and dynamic behavior becomes crucial. Optimal design of the system can result in improved dynamic characteristics. A valve train design methodology is developed in this paper that incorporates an efficient, accurate dynamic system model in the design procedure. The cam profile is synthesized using eight polynomial equations cast in terms of nine nondimensional parameters which are to be optimized. The objective function is cast so as to minimize the residual vibration amplitude of the valve. Several constraints are included such as event duration, maximum tappet lift, maximum tappet velocity, and maximum tappet acceleration.. An adaptive random search technique is used to seek global optimal solutions to the problem. The design methodology was applied to a typical NASCAR valve train and significant increases in engine speed were obtained.

In this study, the combined mesh stiffness characteristics of involute spur and helical gears and their transmission errors due to tooth deflections under load are evaluated. The bending and shear deflections on the contact line of a gear tooth are obtained by the finite element method (using isoparametric plate elements), and the contact deflections are obtained using Hertzian contact theory and the equation of Weber and Banaschek. With these deflections, under the assumption of mathematically exact geometry, the mesh stiffness and compliance of a tooth pair are found using the so called flexibility method. Then using the mesh contact ratio and load sharing ratio, the combined mesh stiffness characteristics of a gear pair and their transmission errors due to the tooth deflections along the line of action are evaluated.