Search Results

THIS STUDY WAS DEVELOPED in response to a component fatigue strength test which determined that if the current #3 engine bearing cap were used in the 2.5L Turbo application, it would be over stressed. Proposed solutions for solving this problem included: a redesigned grey iron cap with additional material in the highly stressed areas, or a cap made from either nodular iron or a free machining steel using current specifications. One of the manufacturing concerns about switching materials is the perceived difference in the machinability of nodular iron and steel. A single point turning evaluation was carried out by Chrysler Motors' Machinability Development Laboratory to compare the machinability of various materials proposed for use in engine bearing caps. Materials tested included: SAE G2500 grey cast iron, the current production material; SAE D45-12 nodular cast iron; and SAE steel grades 1117, 1137, 1215, 12L14, 1215, and 1215 modified (Incut 200).