Inquiry into Extending the Life of Valve Rocker Arms in High Performance and Large Capacity Engine

Valve rocker arms in an engine aid in the timing of the valves. The valves control the air intake and gas exhaust from the cylinder chamber in the engine which affect the efficiency of the engine. Although the rockers are small and fairly inexpensive compared to other parts in the engine the disruption in the timing of the valves can have catastrophic consequences once they fail. Rockers experience considerable cyclic forces due to the repeated tapping on the valves, increasing with the revolutions of the engine. As a result rocker arms exhibit fatigue failure which is amplified by residual stresses that are induced during manufacture. The manufacturing methods employed in making the rockers influence material properties along with the chosen materials which require specific methods of preparation. Proposed solutions include better alloying using powder metallurgy and the use of other materials in the design, such as ceramics, to improve their resilience and strength. The types of testing methods to determine the best solution and other possible areas of consideration, when solving the problem, will also be acknowledged. This presentation will illustrate how inquiry based learning can be used to solve the problem. It will address why valve rocker arms fail while assessing past and present research geared towards finding a solution, with emphasis on the manufacturing methods and material properties