a breather assembly receiving aperture 98 a breather assembly inlet chamber 100 and breather assembly inlet passages 102 the breather assembly receiving aperture 98 includes a ledge 106 that supports the breather assembly 50 within the receiving aperture 98 as best seen in fig4 the central plane 64 of the base 48 extends generally through the center of the breather assembly receiving aperture 98 while the illustrated breather assembly receiving aperture 98 is generally cylindrical in other constructions the breather assembly receiving aperture can take other suitable shapes the illustrated breather assembly inlet passages 102 are generally cylindrical apertures that are substantially normal to the lower wall 54 of the base 48 the breather assembly inlet passages 102 provide fluid communication between the rocker chamber 52 and the breather assembly inlet chamber 100 while the illustrated base 48 includes two breather assembly inlet passages 102 one on each side of the central plane 64 in other constructions the base can include any suitable number of breather assembly inlet passages at any suitable location as best seen in fig5 and 6 grooves 108 a and 108 b in the base 48 and a gasket 110 located between the base 48 and the cylinder head 34 fig3 cooperate to define drainage passageways 112 a 112 b the drainage passageways 112 a 112 b provide fluid communication between the breather assembly inlet chamber 100 and the valve openings 58 a 58 b fig4 respectively the gasket 110 inhibits fluid communication between the valve openings 58 a 58 b and the breather assembly inlet chamber 100 except through the drainage passageways 112 a 112 b referring to fig2 5 and 8 the cover 46 includes a top wall 120 and a perimeter wall or side walls 124 that extend.