A diesel engine comprises: a cylinder head covering one end of a cylinder; a piston having a crown surface opposed to the cylinder head and reciprocatingly movable in the cylinder; and a fuel injection valve attached to the cylinder head, wherein the crown surface of the piston is formed with a cavity which is concaved toward a side opposite to the cylinder head, and has a round shape in top plan view, and the fuel injection valve is formed with a nozzle hole directed toward the inside of the cavity, and wherein a wall surface defining the cavity has a wall segment formed in a periphery of the cavity at a position deviated from a directional direction of the nozzle hole and protruding toward a radially inward side of the piston in approximately parallel to a plane including a central axis of the piston.

A diesel engine includes a cylinder, a cylinder head, a fuel injection valve, and a piston. The piston has a cavity recessed so as to be capable of receiving fuel injected from the fuel injection valve when the piston is positioned at a top dead center, and a notch formed by recessing a part of a circumferential edge of an opening of the cavity radially outward. The notch inclines radially inward at an angle of 0 to 50 relative to a center axis of the cylinder from a piston crown surface toward an inner circumferential wall surface.

A method for remanufacturing or repairing a cylinder head having a bore configured to receive a fuel injector comprises machining a portion of a surface forming the bore to remove imperfections, inserting a repair component into the bore proximate the machined portion of the bore, and spraying material into the bore proximate the machined portion and the repair component, thereby holding the component into place.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

A piston and combustion chamber including piston crown grooves extending from the combustion bowl, promoting swirl and mix within the compressed atmospheric air/gases made up of 78% nitrogen along with 20% oxygen locked in the bowl into an ideal mix with the introduced fuel forming into an ideal charge trapped in the bowl of the piston crown improve thermal efficiencies by overcoming erratic, incomplete and improper combustion resulting in lower emissions that can prevent environmental damages due to pollution from UHC, CO, NO.sub.x, soot with the least carbon dioxide formations when using carbon rich fuels such as diesel engine operations under full load.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

A piston and combustion chamber including piston crown grooves extending from the combustion bowl, promoting swirl and mix within the compressed atmospheric air/gases made up of 78% nitrogen along with 20% oxygen locked in the bowl into an ideal mix with the introduced fuel forming into an ideal charge trapped in the bowl of the piston crown improve thermal efficiencies by overcoming erratic, incomplete and improper combustion resulting in lower emissions that can prevent environmental damages due to pollution from UHC, CO, NO.sub.x, soot with the least carbon dioxide formations when using carbon rich fuels such as diesel engine operations under full load.

A method for remanufacturing or repairing a cylinder head having a bore configured to receive a fuel injector comprises machining a portion of a surface forming the bore to remove imperfections, inserting a repair component into the bore proximate the machined portion of the bore, and spraying material into the bore proximate the machined portion and the repair component, thereby holding the component into place.

A piston crown is provided for a piston in an internal combustion engine arrangement that includes a cylinder, the piston crown having a piston bowl surface adapted for facing a combustion chamber in the cylinder, wherein the piston bowl surface including a circumferential rim portion, a floor portion connected to and surrounded by the circumferential rim portion, a plurality of circumferentially spaced protrusions in the circumferential rim portion, at least one spray impingement portion, located between two adjacent protrusions. The spray impingement portion includes a reflection surface, being defined by that each possible normal to the reflection surface is directed towards a central axis of the piston, and forming an angle being within a range of a constant angle 10 with the central axis, wherein the constant angle is at least 50.

A piston may include an outer peripheral surface and a crown. The outer peripheral surface may include first and second openings spaced about and extending through the outer peripheral surface. The crown may include a recess at least partially defined by a first lobe in fluid communication with the first opening and a second lobe in fluid communication with the second opening. Each of the first and second lobes may be recessed relative to an adjacent portion of the recess of the crown.