BEARING SUPPORT INSERT

摘要

A bearing insert (14) for being cast into an aluminum alloy engine block (10) is made by a ferrous powder metal sintering process to make a skeleton structure which is permeable to the molten aluminum alloy in the block casting process. The insert (14) is made of a material having a similar composition as the bearing cap (16) so as to equalize machining and thermal expansion properties of the cap (16) and block (10) so as to provide improved roundness of the bearing (18) in the machining operations for forming the bearing support and in operation of the engine.