The present disclosure relates to a system for controlling ignition of an air/fuel mixture intake charge directed into an internal combustion engine. The system may have a longitudinally movable inner cylinder liner configured to fit within a cylinder wall portion of an internal combustion engine, and able to receive a piston of the engine therein. A portion of the inner cylinder liner defines an internal volume forming a combustion chamber, and the internal volume controls a compression ratio of the cylinder. The system also has a cylinder head assembly operatively associated with the inner cylinder liner and able to move linearly to cause longitudinal displacement of the inner cylinder liner relative to the cylinder wall portion. This enables the volume of the combustion chamber to be further varied, to thus further vary the compression ratio.

At least one thermal barrier coating member mounted on an inner wall surface, facing a combustion chamber of an engine, of a cylinder liner accommodating a piston slidably along an axial direction, is provided with: a base layer configured to be detachably fitted into a recess formed in the inner wall surface of the cylinder liner; and a thermal barrier coating layer formed on an opposite side of the base layer from the inner wall surface of the cylinder liner. The thermal barrier coating layer is disposed above a piston ring which is positioned at an uppermost position in the axial direction of the cylinder liner when the piston reaches top dead center.

A quick return oil cylinder liner is disclosed. The cylinder liner includes an elongated cylindrical body having an outer surface and an inner surface defining a liner central axis extending between a first liner axial end and a second liner axial end. The inner surface is configured to form a combustion chamber with a piston and an engine housing. A quick oil return part is arranged on the inner surface of the cylinder liner corresponding to a non-skirt part of the piston. The oil return part is positioned below a position of the inner surface corresponding to an oil blade of an oil ring of the piston when the piston is positioned at a bottom dead center position. The oil return part extends to the second linear axial end and forms at opening at the second liner axial end.

An engine includes an engine block and a cylinder head mounted to the engine block. The engine block includes a bore elongated along an axis and a liner disposed in the bore and extending annularly about the axis. The liner includes a seal surface and a fire dam disposed radially inward from the seal surface. The fire dam extends along the axis from the seal surface towards the cylinder head. The engine further includes a head gasket disposed between the engine block and the cylinder head. The head gasket extends endlessly around the fire dam. The engine further includes a shim seated between the seal surface and the head gasket and abutting the seal surface and the head gasket. The shim is disposed radially outward from the fire dam and extending annularly about the axis.

An internal combustion engine includes including a fuel reformation cylinder for reforming a fuel and an output cylinder for yielding an engine power by combusting a fuel or a reformed fuel, wherein at least a part of the surfaces constituting a volume-variable reaction chamber of the fuel reformation cylinder has a highly heat-insulative material.

Systems and methods are provided for a cylinder liner for an engine including a catcher feature on a side surface to provide radial support and improved coolant sealing. In one example, the catcher feature may include a continuous stepped catcher extending from the cylinder liner body and a stepped tab of the engine block, the stepped catcher resting on the stepped tab. Also, a radial flange in the upper portion of the cylinder liner may be coupled to the engine block, the coupling sealed via an O-ring nestled in a groove formed in the radial flange.

A piston for an internal combustion engine includes a plurality of valve pockets formed in a piston rim, the valve pockets forming fluid flow paths through the piston rim. Each of the valve pockets includes a central step standing proud of a pocket floor to limit a fluid flow area through the pocket and slow combustion gas flow from a combustion bowl toward a cylinder liner and thereby reduce displacement of an engine oil film thereon.

A cylinder structure of an internal combustion engine contains: a body, two lids, and multiple positioning elements. The body has a combustion chamber, an air inlet, an air outlet, and two scavenging units. A respective scavenging unit has a first scavenging orifice, a second scavenging orifice, a first fringe, a second fringe, a first engagement portion, and a first fixing orifice. The two lids are configured to close the first scavenging orifice and the second scavenging orifice, an air conduit is defined between a respective lid and an external fence of the body, and the respective lid has multiple second fixing orifices. A respective positioning element has a stem and at least one hook, the stem extends into the first engagement portion, and the stem is rotated so that the at least one hook contacts with the respective lid, and the respective lid is connected with the body.

A cylinder liner that is casted in a block and defines a cylinder bore for one cylinder includes: a cylindrical liner body; a projection part including a plurality of projections on an outer peripheral surface of a part of the liner body; and a bore adjacent part inclined at a predetermined angle to an axial direction of the body and extending in the inclination direction, at a predetermined part between an upper side end and a lower side end of the body, of the outer peripheral surface of the body, which faces another cylinder bore to be adjacent when casted in the block. The outer peripheral surface of the bore adjacent part is positioned more on an inner side of the body than the outer peripheral surface above and below, and is formed such that the projections are absent on at least a part of the outer peripheral surface.

A method of manufacturing an internal combustion engine is provided. The engine includes a cylinder forming member, a piston reciprocatably accommodated in a cylinder, an injector which supplies fuel into a combustion chamber, and a heat insulating layer covering at least a part of a combustion-chamber wall surface and having a lower heat conductivity than the combustion-chamber wall surface. The method includes applying a coating material that is a material of the heat insulating layer to the combustion-chamber wall surface, assembling the piston to the cylinder forming member while the coating material is uncured, and heating the coating material to be cured by combusting the fuel injected from the injector and reciprocating the piston. The heating the coating material includes injecting the fuel from the injector at least in an early stage of the heating so that the injected fuel adhering to the surface of the coating material is suppressed.