Engine head cover structure

An engine head cover structure has a head cover joined to the upper end of a cylinder head so as to define a valve operation chamber therebetween. The head cover includes therein an oil recovery chamber to which oil resided in the valve operation chamber is recovered by suction and a breather chamber that removes blowby gas from the valve operation chamber being provided in the head cover. The breather chamber is defined between a partition plate mounted on an inner wall of the head cover via clips and a surface of the roof of the head cover, and the oil recovery chamber is defined between the partition plate and a partition body welded thereto. It is thus possible to form the oil recovery chamber and the breather chamber without splitting the roof of the head cover, thereby making inspection of the joint for oil tightness unnecessary.