A cylinder head for an internal combustion engine comprising a prechamber (3), wherein a prechamber gas valve (5) is fitted into a cavity of the cylinder head (2) and the prechamber gas valve (5) is connected to the prechamber (3) by way of a flow transfer passage (10), wherein the flow transfer passage (10) for a given cross-sectional area immediately downstream of the prechamber gas valve (5) is of such a length that in operation of the cylinder head (2) mounted in an internal combustion engine in a compression stroke of the combustion process propellant gas which flow out of the prechamber gas valve (5) forms a gas cushion at least in a first portion (8) of the flow transfer passage (10), that adjoins the prechamber gas valve (5).

A precombustion chamber engine comprises: a cylinder head defining a main combustion chamber together with a cylinder liner and a piston top surface; a precombustion chamber cap mounted on the cylinder head by inserting a distal end portion of the precombustion chamber cap into an insertion hole formed in the cylinder head; a precombustion chamber holder disposed inside the cylinder head; and a precombustion chamber cap holding member fixed to the precombustion chamber holder and configured to suspend and support the precombustion chamber cap. The precombustion chamber cap includes a reduced diameter portion with a diameter decreasing from a proximal end portion of the precombustion chamber cap to an intermediate portion that has a smaller diameter than the proximal end portion. The precombustion chamber cap holding member is configured to lock the reduced diameter portion and to have a gap between the precombustion chamber cap holding member and the proximal end portion when the precombustion chamber cap holding member suspends and supports the precombustion chamber cap.

A prechamber assembly includes a cylinder head including a coolant cavity, a prechamber body located within the cylinder head, the prechamber body including a nozzle, and an annular sleeve radially surrounding a portion of the prechamber body. The sleeve includes a plurality of coolant inlet holes. A portion of the prechamber body is radially spaced from the sleeve to form a coolant sleeve annulus extending along a length of the prechamber body above the coolant inlet holes. The coolant cavity and the coolant sleeve annulus are in fluid communication through the plurality of coolant inlet holes.

To meet both a request to improve the thermal efficiency in medium load operation of an engine and a request to suppress knocking in high load operation of the engine, the engine includes a main combustion chamber including a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24, an aperture ratio, which is the ratio of a total cross-sectional area of the plurality of injection holes to a volume of the pre-chamber, is not less than 0.0078 mm.sup.-1 and not more than 0.0145 mm.sup.-1, and the volume of the pre-chamber 15 is not less than 0.0430 cm.sup.3 and not more than 0.5631 cm.sup.3.

Methods and systems are provided for injecting gaseous fuel during an engine start. In one example, a method comprises generating gaseous fuel via a fuel gasification device and injecting the gaseous fuel via a fuel injector. The fuel injector is configured to inject adjacent to an ignition device.

Methods and systems are provided for injecting gaseous fuel during an engine start. In one example, a method comprises generating gaseous fuel via a fuel gasification device and injecting the gaseous fuel via a fuel injector. The fuel injector is configured to inject adjacent to an ignition device.

An internal combustion engine includes a combustion chamber with a cylinder head, a cylinder, and a piston. The internal combustion engine also includes at least one intake valve and at least one exhaust valve that are connected to the combustion chamber, a fuel injector that injects fuel into the combustion chamber, at least two ignition devices arranged in the combustion chamber, and control means that control the valves, the injector, and the ignition means. The control means operate the engine according to different combustion modes including a controlled ignition combustion mode, a compression ignition combustion mode, and an assisted compression ignition combustion mode. The control means activate the ignition means in the assisted compression ignition combustion mode.

An internal combustion engine includes a combustion chamber with a cylinder head, a cylinder, and a piston. The internal combustion engine also includes at least one intake valve and at least one exhaust valve that are connected to the combustion chamber, a fuel injector that injects fuel into the combustion chamber, at least two ignition devices arranged in the combustion chamber, and control means that control the valves, the injector, and the ignition means. The control means operate the engine according to different combustion modes including a controlled ignition combustion mode, a compression ignition combustion mode, and an assisted compression ignition combustion mode. The control means activate the ignition means in the assisted compression ignition combustion mode.

A fuel gas feed and ignition apparatus for a gas engine (1) with a combustion chamber includes a number of injection channels (37), a main fuel gas feed line (24) for main fuel gas in which a main fuel gas valve (21) is arranged, and a number of torch channels (52) for hot combustion gas connected to a pre-combustion chamber (15), wherein an ignition fuel supply line (17) leads to the pre-combustion chamber (15) and a pre-combustion chamber valve (18) is arranged in the ignition fuel supply line (17). Control of both the time and the duration and thus also the quantity of the injection of main fuel gas, as well as of ignition fuel for the pre-combustion chamber completely independently of one another and in a precise and, above all, rapid manner is achieved in that both the main fuel gas valve (21) and the pre-combustion chamber valve (18) are embodied as an electrically-actuated, electronically-controlled valve.

An internal combustion engine, includes at least one cylinder, wherein the or each cylinder includes a main combustion chamber for burning fuel in the cylinder, wherein an assembly serving to supply and/or ignite fuel is installed on a cylinder head of each cylinder between gas exhaust valves of the cylinder in such a way that the assembly is inserted into a cut-out in the cylinder head of the cylinder and is sealed to said cut-out, wherein a segment of the assembly that is inserted into the cut-out in the cylinder head of the cylinder has an oval contour in the cross-section, and wherein a bounding surface of said segment of the assembly, which bounding surface lies in the sealing region, is contoured in such a way that said bounding surface is continuously convexly curved outward in the peripheral direction.