A fuel injector assembly for an engine. The engine includes a cylinder head defining a through-hole. The fuel injector assembly includes an insert, having a first end and a second end, configured to be received within the through-hole and coupled to the cylinder head. The insert defines a bore extending from the first end to the second end. The fuel injector assembly further includes a fuel injector including a plurality of orifices, received within the bore of the insert; and a duct structure including a plurality of ducts, coupled to the insert such that the plurality of ducts align with the plurality of orifices to at least partially receive one or more fuel jets from the plurality of orifices of the fuel injector.

An engine includes a housing and a combustion assembly. The combustion assembly includes an annular bore and a combustion piston assembly disposed within the annular bore. The combustion piston assembly includes a set of pistons, a first sealing ring connected to each piston and a second sealing ring connected to each piston. The second sealing ring is configured to provide selective access between the annular bore and at least one fluid conduit carried by the engine. The engine includes at least one valve configured to move between a first position within the annular bore to allow the combustion piston assembly to travel within the annular bore from a first location proximate to the at least one valve to a second location distal to the at least one valve and a second position within the annular bore to define a combustion chamber.

An engine includes a housing and a combustion assembly. The combustion assembly includes an annular bore and a combustion piston assembly disposed within the annular bore. The combustion piston assembly includes a set of pistons, a first sealing ring connected to each piston and a second sealing ring connected to each piston. The second sealing ring is configured to provide selective access between the annular bore and at least one fluid conduit carried by the engine. The engine includes at least one valve configured to move between a first position within the annular bore to allow the combustion piston assembly to travel within the annular bore from a first location proximate to the at least one valve to a second location distal to the at least one valve and a second position within the annular bore to define a combustion chamber.

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.

An engine includes a cylinder liner, a cylinder block, a cylinder head, a seal portion, and a gap member. The seal part is provided to surround the outer circumferential side of the cylinder liner and configured to seal between the cylinder block and the cylinder head. At a position on the inner circumferential side of the seal part, the gap member fills the gap between the cylinder head and the end surface of the inner peripheral side of the cylinder liner, and is made of a material having a lower Young's modulus than the seal part.

An engine includes a cylinder liner, a cylinder block, a cylinder head, a seal portion, and a gap member. The seal part is provided to surround the outer circumferential side of the cylinder liner and configured to seal between the cylinder block and the cylinder head. At a position on the inner circumferential side of the seal part, the gap member fills the gap between the cylinder head and the end surface of the inner peripheral side of the cylinder liner, and is made of a material having a lower Young's modulus than the seal part.

The diesel engine is provided with a cylinder, a cylinder head, a fuel injection valve, and a piston. The piston has a cavity, and a notch formed in a circumferential edge of the cavity. The notch includes a first recessed portion which is recessed radially outward from an inner circumferential wall surface of the cavity, and a second recessed portion which is recessed from a crown surface of the piston toward a bottom side of the cavity and continuously extends radially outward from an end, on the crown surface side, of the first recessed portion. A vertical wall, on a downstream side of a swirl flow, of the second recessed portion is formed to extend, in an arched manner, radially inward and toward the downstream side of the swirl flow from a position corresponding to a radially outer side end of the second recessed portion in a plan view.

A porous ceramic particle (16) has a pair of main surfaces (161, 162) in parallel with each other. An average porosity in a range (633) extending from one main surface (161) toward the other main surface (162) and having a thickness which is one fourth of a particle thickness that is a distance between the main surfaces is higher than that in a range (632) which is positioned in the center between the pair of main surfaces and has a thickness which is half of the particle thickness. The upper main surface (161) is a surface to be placed on an object. By limiting an area having a high porosity to the vicinity of the one main surface (161), it is possible to cause the porous ceramic particle (16) to have low thermal conductivity and low heat capacity and suppress a decrease in the mechanical strength.

A combustion system for an internal combustion engine includes combustion chamber that is defined between a cylinder head and a top surface of a piston. The combustion system also includes a fuel injector having an injector tip. The injector tip defines a nozzle disposed in fluid communication with the combustion chamber for dispensing a fuel jet into the combustion chamber. A bluff body is positioned within the combustion chamber such that an axis of the dispensed fuel jet is incident on an anterior portion of the bluff body proximal to the injector tip. The anterior portion has a contour that is adapted to split the dispensed fuel jet into at least two turbulent fuel streams and facilitate mixing of each fuel stream with an oxidant present in the combustion chamber.