Abstract: A cylinder head of an engine is disclosed, the cylinder head including an upper deck, a lower deck, and a sidewall extending between the upper deck and the lower deck. The lower deck defines a block-engaging portion and a combustion chamber flame deck. The combustion chamber flame deck is spaced apart from the block-engaging portion. An engine is also disclosed that includes a cylinder block having a cylinder bore, and a piston slidably positioned within the cylinder bore. The engine also includes a cylinder head having a lower deck connected to the cylinder block, the lower deck defining a block-engaging portion and a combustion chamber flame deck. The combustion chamber flame deck is spaced apart from the block-engaging portion by a recess.

Abstract: An engine that is operating with a combustible intake mixture may begin in to runaway, or in other words, uncontrollably operate at excessive speeds. In order to shutdown a runaway engine, the present disclosure determines whether an engine is operating in a runaway condition. If the engine is operating in the runaway condition, a compression inhibiting mechanism is moved from a first position in which compression ignition can occur within at least one combustion chamber and a second position in which compression ignition cannot occur within the at least one combustion chamber.