Abstract: A cylinder head for an internal combustion engine of either a two-cycle operation or a four-cycle operation is disclosed. The cylinder head includes an intake port, an exhaust port, a dual-function chamber, a poppet valve positioned within the dual-function chamber, and a flapper valve also positioned within the dual-function chamber, capable of sealing the intake port from the dual-function chamber, capable of sealing the exhaust port from the dual-function chamber. If the cylinder head is for a two-cycle engine, an injector may be positioned within the cylinder head so that fuel is injected either within the dual-function chamber, or directly injected within the combustion chamber. A process of operating the cylinder head in conjunction with an internal combustion engine is also disclosed.