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Cam phasing and Variable Valve Actuation (VVA) are used increasingly to alter the opening and closing of the valves to improve fuel economy by most of the automotive engine manufacturers. In instances where the design constraints require use of rolling and sliding follower interfaces with camshaft lobes, several solutions are possible. However, finding an inexpensive solution is challenging. This paper briefly reviews some of the conventional wear test methods that have primarily been used for piston ring cylinder liner wear assessments. Later on a new test method developed using the modified Optimol SRV 4 wear tester is described. This test method was used to assess and rank material combinations for sliding wear assessment of various camshaft lobe and follower components.

This paper presents an overview of techniques for measuring friction using bench tests and fired engines. The test methods discussed have been developed to provide efficient, yet realistic, assessments of new component designs, materials, and lubricants for in-cylinder and overall engine applications. A Cameron-Plint Friction and Wear Tester was modified to permit ring-in-piston-groove movement by the test specimen, and used to evaluate a number of cylinder bore coatings for friction and wear performance. In a second study, it was used to evaluate the energy conserving characteristics of several engine lubricant formulations. Results were consistent with engine and vehicle testing, and were correlated with measured fuel economy performance. The Instantaneous IMEP Method for measuring in-cylinder frictional forces was extended to higher engine speeds and to modern, low-friction engine designs.

This new book provides a comprehensive overview of various lubrication aspects of a typical powertrain system including the engine, transmission, driveline, chassis, and other components. The manual addresses major issues and current development status of automotive lubricant test methods. Topics also cover advanced lubrication and tribochemistry of the powertrain system, such as diesel fuel lubrication, specialized automotive lubricant testing development, filtration testing of automotive lubricants, lubrication of constant velocity joints, and biodegradable automotive lubricants.