Cylinder head for internal-combustion engines

A cast cylinder head for an internal-combustion engine, comprising a combustion-space-side boundary wall defining at least one circular valve opening, and a duct wall defining a charge cycle duct communicating with the at least one valve opening, an interior surface of the charge cycle duct being offset relative to a peripheral surface of the boundary wall defining the valve opening within a defined, maximally acceptable tolerance field, said duct wall defining a machining allowance which increases toward the valve opening and which, at the valve opening, corresponds in size to at least a maximally acceptable amount of offset, an area of the charge cycle duct proximate the opening being cuttingly machined on an interior side such that the interior surface of the charge cycle duct changes in each case without offset into the valve opening,

• wherein a compensating groove is provided proximate the machining allowance of the charge cycle duct in the cast crude condition, extending in the circumferential direction and having a flat V-shaped cross-section,
• flanks of said groove converging approximately in the center of the groove acutely with respect to a base of the groove, said flanks having a convexly shaped cross-section and being curved,
• the compensating groove being provided at least in the area of a convex interior wall of said charge cycle duct,
• the compensating groove extending above one of an upper edge of a recess for a valve seat ring and a valve seat in the valve opening a distance of approximately 20 to 30% of the inside diameter of the valve opening,
• the groove base being situated outside an ideal course of the interior surface so that not only is there no machining allowance in this area but the real interior surface of the charge cycle duct locally has an overmeasure with respect to said ideal course.