Methods and systems for unsticking a stuck gaspath actuator are disclosed. In one embodiment, an engine operating method includes adjusting exhaust valve timing of one or more cylinders of an engine in response to an indication that a gaspath actuator is stuck in position. In this way, pressure waves in an exhaust manifold and/or an intake manifold may be generated, which may act to unstick the gaspath actuator.

A compression ignited combustion engine has at least one cylinder and first and second gas intake ports in a cylinder head restricting a combustion chamber. One gas intake passage leads to the two ports and is widened in a Y-shaped end influencing gas entering each port into a tangential flow in opposite direction with respect to the flow into the other port. The first intake port is designed to allow gas entering this port to continue said tangential flow so as to enter the combustion chamber in a swirl in a first rotation direction, whereas the second intake port is designed to guide gas entering this port to also enter the combustion chamber in a swirl in said first rotation direction.

The piston has a contoured combustion bowl with a radially inner shelf portion that is spaced axially away from the radially outer lip portion a first axial distance, and a swirl pocket that extends radially from the radially inner shelf portion and defines a lower axial extremity that is spaced axially away from the radially outer lip portion a second axial distance that is greater than the first axial distance. The swirl pocket defines a tangent extending in the radially outer direction, forming an acute angle with the radially outer lip portion ranging from 70 degrees to 80 degrees.

The piston has a contoured combustion bowl with a radially inner shelf portion that is spaced axially away from the radially outer lip portion a first axial distance, and a swirl pocket that extends radially from the radially inner shelf portion and defines a lower axial extremity that is spaced axially away from the radially outer lip portion a second axial distance that is greater than the first axial distance. The swirl pocket defines a tangent extending in the radially outer direction, forming an acute angle with the radially outer lip portion ranging from 70 degrees to 80 degrees.

An intake device of an internal combustion engine includes a partition, a control valve, and a third passage. The partition divides an interior of an intake pipe that couples with a combustion chamber into a first passage and a second passage. The control valve is capable of opening and closing the first passage. The third passage opens at or near a coupling site between the partition and the intake pipe on an inner face of the second passage. The third passage is configured to be capable of sucking in at least a part of a boundary layer produced at or near the coupling site by a vapor flowing through the second passage in a state in which the control valve is working in a direction of closing the first passage.

Combustion stability can be improved while HC and PN discharged from a combustion chamber are prevented. In an ECU that controls a fuel injection device installed in a combustion chamber of an internal-combustion engine so as to be able to inject fuel in a direction intersecting with a sliding direction of a piston, a pressure value of the fuel supplied to the fuel injection device is acquired, control is performed such that the fuel injection device injects the fuel at least twice in a compression stroke, and control is performed such that fuel injection timing of at least one time in the compression stroke is advanced earlier than fuel injection timing of a time corresponding to the high pressure value of the fuel when the acquired fuel pressure value is low.

A control apparatus for an engine includes an engine, a state quantity setting device, a spark plug, and a controller. The spark plug ignites air-fuel mixture at predetermined ignition timing so that unburned air-fuel mixture combusts by autoignition after start of combustion of the air-fuel mixture by the ignition, and the controller adjusts a heat amount ratio in accordance with an operation state of the engine through change of the ignition timing, the heat amount ratio representing an index associated with a ratio of an amount of heat generated when the air-fuel mixture combusts by flame propagation with respect to a total amount of heat generated when the air-fuel mixture combusts in the combustion chamber.

In a spark-ignition internal combustion engine in which a protrusion including an intake-side inclined surface and an exhaust-side inclined surface is formed on a top surface of a piston, and a cavity is formed in the protrusion at a position associated with a spark plug, the intake-side inclined surface and the exhaust-side inclined surface are formed in such a way that a ratio of a length of the exhaust-side inclined surface with respect to a length of the intake-side inclined surface is 1.25 or larger in a cross section passing through a center axis of the piston and orthogonal to an axis direction of a crankshaft.

In a spark-ignition internal combustion engine in which a protrusion including an intake-side inclined surface and an exhaust-side inclined surface is formed on a top surface of a piston, and a cavity is formed in the protrusion at a position associated with a spark plug, the intake-side inclined surface and the exhaust-side inclined surface are formed in such a way that a ratio of a length of the exhaust-side inclined surface with respect to a length of the intake-side inclined surface is 1.25 or larger in a cross section passing through a center axis of the piston and orthogonal to an axis direction of a crankshaft.

Diesel engines modified to be fueled with gaseous fuels experience problems with knocking and pre-ignition, limiting the compression ratio and efficiency of the engine. A new combustion chamber for a gaseous fueled internal combustion engine, in which the combustion chamber is defined by a cylinder head, a bore in a cylinder block and a piston reciprocating in the bore, comprises a piston portion of the combustion chamber defined by a recessed shape in a piston crown; and a head portion of the combustion chamber defined by a recessed surface in the cylinder head. A ratio between the piston portion of combustion chamber volume and the head portion of combustion chamber volume is in a range of 0.7 to 1.3.