Cylinder head for a water-cooled internal combustion engine

In a cylinder head for a water-cooled internal combustion engine, including a lower cylinder head portion and an upper cylinder head portion fitting over the lower cylinder head portion along a parting plane traversing cooling chambers complementally formed in the lower and upper cylinder head portions;

• said lower cylinder head portion having intake and exhaust ports and walls extending exclusively from said intake and exhaust ports;
• said walls having engagement faces for being tightened to a cylinder block of the engine;
• said walls bounding liquid-guiding chambers formed in said lower cylinder head portion;
• said upper cylinder head portion carrying a valve operating assembly of the engine;
• the cylinder head further having a cylinder head cover situated above the upper cylinder head portion and covering said valve operating assembly;
• the improvement wherein said lower cylinder head portion has a circumferential lower wall bounding a liquid-guiding chamber provided in said lower cylinder head portion and serving exclusively for returning oil from said upper cylinder head portion;
• and a circumferential upper wall constituting an upward continuation of said circumferential lower wall and extending from said intake and exhaust ports;
• said circumferential upper wall having a circumferential seating face supporting said cylinder head cover and constituting the sole support therefor;
• said upper cylinder head portion being out of contact with said cylinder head cover and being accommodated substantially in its entirety in a space surrounded by said cylinder head cover.