Engine cylinder head cooling features and method of forming

摘要

A method of forming a cylinder head includes casting the cylinder head to include an integral cast-in exhaust manifold. The integral cast-in exhaust manifold defines an intermediate exhaust gas passage in fluid communication with exhaust ports and an exhaust gas outlet passage in fluid communication with the intermediate exhaust gas passage. The cast cylinder head includes a coolant cavity to receive a cooling fluid. The coolant cavity includes first and second portions extending around an outer circumference of the exhaust gas outlet passage separated from one another by a first cast-in wall. The method further includes machining the first cast-in wall to provide fluid communication between the first and second portions of the coolant cavity. Machining the first cast-in wall forms a first coolant passage created by the first and second portions of the coolant cavity and the machined passage around the outer circumference of the exhaust gas outlet passage.