Patent ID: 7086378

Claim:
A direct fuel injection internal combustion engine comprising: an engine block having at least one cylinder bore with a piston mounted to reciprocate therein along a reciprocation axis; a cylinder head disposed on the engine block with a combustion chamber formed by an combustion chamber upper surface of the cylinder head, the cylinder bore and a top surface of the piston, the cylinder head including a recess portion continuously formed within the combustion chamber upper surface; and a fuel injector disposed in the recess portion of the cylinder head above a center portion of the piston, the fuel injector being arranged such that a tip of the fuel injector is located above the combustion chamber upper surface within the recess portion to inject fuel such that a fuel injection center axis is substantially parallel to the reciprocation axis of the piston; the recess portion of the cylinder head having a peripheral side wall surface with a similar geometric cross sectional outline along planes perpendicularly arranged relative to the fuel injection center axis, the geometric cross sectional outline of the peripheral side wall surface having a first wall section being spaced by a first distance from the fuel injection center axis that is shorter than a second distance between a second wall section and the fuel injection center axis as measured perpendicularly to the fuel injection center axis, the second wall section defining a channel extending longitudinally away from the tip of the fuel injector that is configured and arranged to reduce negative pressure within the recess portion otherwise resulting from fuel being injected from the fuel injector.