Cylinder head for DOHC internal combustion engine with four valves per cylinder

摘要

In a cylinder head for a DOHC internal combustion engine of the type having four valves per cylinder, a thin, flat recess is formed in the wall above an upper deck in such a way as to communicate an oil supply passage and an upper side of the upper deck. An oil return passage is provided adjacent a head bolt hole for providing communication between the recess and a lower side of a lower deck so that oil having lubricated parts and portions of the engine flows down to the upper side of the upper deck from which it is conducted to the lower side of the lower deck through the recess and the oil return passage. From the lower side of the lower deck, oil is returned to an oil pan by way of a cylinder block.