Methods and systems are provided for a 2-port integrated exhaust manifold for an inline-3, inline-6, V-6, and/or V-12 engine. In one example, a system may include an exhaust manifold integrated within a cylinder head of an engine block. The integrated exhaust manifold may include a first set of two runners from a first outer cylinder coupled to a first manifold exhaust port, a second set of two runners of a second outer cylinder coupled to a second manifold exhaust port, and one runner of an inner cylinder coupled to the first manifold exhaust port and another runner of the inner cylinder coupled to the second manifold exhaust port.

A valve arrangement for an internal combustion engine having at least one intake valve, at least one exhaust valve, and at least one reciprocating piston. Each intake valve is seated in the cylinder head at a lesser distance from the piston than is each exhaust valve. Also, each exhaust valve has a cross sectional area less than seventy percent of the cross sectional area of each intake valve. The cross sectional area of each exhaust valve may be for example sixty to sixty-two percent of the cross sectional area of each intake valve.

An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

A cylinder head of a multi-cylinder engine is provided, the cylinder head including a plurality of ceiling parts for respective cylinders, and a water jacket. Each ceiling part is connected to an intake port including a primary port and a secondary port aligned in a cylinder-row direction, and is attached with an in-cylinder pressure sensor. A plug is attached to a hollow part of the cylinder head corresponding to a core print provided to a core of the water jacket, and is disposed at a position corresponding to a location between certain cylinders. The in-cylinder pressure sensor is attached at a position on an opposite side from the plug with respect to a cylinder center axis in the cylinder-row direction. Positions of the primary and secondary ports connected to each ceiling part are interchanged in the cylinder-row direction according to the position of the in-cylinder pressure sensor.

The present invention discloses an apparatus for optimizing the fuel/air mixing process of an internal combustion engine. The bottom surface of the cylinder head is provided with a plurality of brackets; a ring is fixed to the brackets; and the ring may be an integrated ring body and may also be composed of a plurality of small segments. The ring is positioned opposite to a fuel injector and located in an area where fuel flows in the combustion chamber. The ring can continuously guides the fuel during the fuel injection process. The ring can be arranged in the liquid-phase region, the gas-liquid two-phase region or the gas-phase region. When the location of the ring interferes with the movement of valves of the internal combustion engine, the part of the ring body that interferes with the movement of the valves can be removed.

A valve bridge to operatively interface with a rocker arm and a valve, and systems, assemblies, and methods thereof can comprise: a body, of the valve bridge, having a first side and a second side opposite the first side, a first leg of the valve bridge extending from the first side of the body, a second leg of the valve bridge extending from the first side of the body, and a third leg of the valve bridge extending from the first side of the body. A first pin can extend from an end of the first leg opposite the body, and a second pin can extend from an end of the second leg opposite the body.

An engine includes a cylinder block, a cylinder head, and a piston. The cylinder head is connected to the cylinder block. The piston is movably connected to the cylinder block. The cylinder block, the cylinder head, and the piston form a combustion chamber. The cylinder head includes an intake valve hole and an exhaust valve hole. An intake valve is disposed at the intake valve hole and an exhaust valve is disposed at the exhaust valve hole. A barrier protrusion is protruded at the edge of the intake valve hole away from the exhaust valve hole. The included angle between a first connecting line connecting a first end of the barrier protrusion and a center of the intake valve hole and a second connecting line connecting a second end of the barrier protrusion and the center of the intake valve hole is greater than 120 degrees and less than or equal to 180 degrees.

A cylinder head assembly includes a cylinder head casting, and an injector sleeve within an injector bore in the cylinder head casting. The injector sleeve includes a first sleeve end, and an injector clamping surface formed by an inner sleeve surface adjacent to a cylindrical second sleeve end. The injector sleeve further includes a sleeve clamping surface in contact with an upward facing middle deck surface of the cylinder head casting, and a reaction wall extending between the injector clamping surface and the sleeve clamping surface to transfer an injector clamping load to the upward facing middle deck surface.

A cylinder head of a multi-cylinder engine is provided, the cylinder head including a plurality of ceiling parts for respective cylinders, and a water jacket. Each ceiling part is connected to an intake port including a primary port and a secondary port aligned in a cylinder-row direction, and is attached with an in-cylinder pressure sensor. A plug is attached to a hollow part of the cylinder head corresponding to a core print provided to a core of the water jacket, and is disposed at a position corresponding to a location between certain cylinders. The in-cylinder pressure sensor is attached at a position on an opposite side from the plug with respect to a cylinder center axis in the cylinder-row direction. Positions of the primary and secondary ports connected to each ceiling part are interchanged in the cylinder-row direction according to the position of the in-cylinder pressure sensor.

A quantitative one-way oil gas lubricant system and a method for a 4-stroke engine, including a preceding stage quantitative oil intake orifice that is connected to a lubricant case on a wall of a crankcase of the 4-stroke engine, and a final stage quantitative airflow orifice disposed at a cylinder cover of the 4-stroke engine, are provided. A diameter of the preceding stage quantitative oil intake orifice D.sub.1 and a diameter of the final stage quantitative airflow orifice satisfy an equation: D.sub.1/D.sub.3=0.8-1.5, wherein a one-way connected oil gas lubricant channel is disposed between the preceding stage quantitative oil intake orifice and the final stage quantitative airflow orifice. A lubricant oil sucked from the preceding quantitative oil intake orifice by the crankcase flows along the oil gas lubricant channel and lubricates the engine parts that the channel passes through in turns. Finally, a minute quantity of waste oil gas that flows out from the final stage quantitative airflow orifice is introduced into a cylinder of the 4-stroke engine and is to be burned completely. The supply quantity of the lubricant oil may be controlled, and no extra lubricant oil gas may flow out from the final stage quantitative airflow orifice, therefore, the quantitative and one-way lubricating is realized.