Methods and systems are provided for a multi-layered steel gasket for an internal combustion engine. In one example, a system may include a pressure relief device arranged in the multi-layered steel gasket for releasing pressure from one or more fluids flowing through passages of the internal combustion engine.

Methods and systems are provided for a sub-assembly. In one example, a method for the subassembly includes separating a monoblock of the subassembly into two separate portions and applying a sealing material to at least one of the two separate portions and rejoining the portions.

A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder; and an air intake duct forming part of an air intake path for delivering the flow of air to the air intake. The engine further includes a flow sensing arrangement located in the air intake duct and comprising a flow meter configured to generate a signal indicative of a flow rate of the flow of air through the air intake duct, and a bluff body located in the air intake duct upstream of the flow meter, wherein the flow meter is a vortex shedding flow meter.

In an internal combustion engine, a breather chamber can be formed without increasing the number of component parts. The internal combustion engine (1) comprises an engine block (30) defining a cylinder (2); a case member (19) fastened to a lower part of the engine block to define a crank chamber (4) jointly with the engine block; and a bearing member (50) fastened to the engine block in the crank chamber to rotatably support a crankshaft; wherein the engine block is provided with a central recess (134) formed in a part thereof to which the bearing member is fastened, a blow-by gas inlet passage (112, 116, 121) communicating the central recess with the crank chamber, and a blow-by gas return passage (122, 118) forming a part of a passage communicating the central recess with an intake device, the central recess and the bearing member jointly defining a central breather chamber.

An engine with a reduced cooling loss, may include a cylinder block, a piston and a cylinder head, wherein the engine displacement chamber is 300cc-700cc and an entire combustion chamber volume including a first volume of the cylinder block and a second volume of the cylinder head is defined between an inner surface of the cylinder head, a distal end of an intake valve mounted in the cylinder head when the intake valve is closed, and an upper surface of the piston positioned at a top-dead center of the engine in the cylinder block, wherein a compression ratio between an engine displacement chamber and the entire combustion chamber is 10.0 or more:1, and wherein the second volume of the cylinder head is 40%-70% of the entire combustion chamber volume.

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.

Methods and systems are provided for a multi-layered steel gasket for an internal combustion engine. In one example, a system may include a pressure relief device arranged in the multi-layered steel gasket for releasing pressure from one or more fluids flowing through passages of the internal combustion engine.

An internal combustion engine has a plurality of cylinders and transmission arranged adjoining the engine. If designating an average height of a combustion chamber in a region inside from a virtual cylindrical surface passing through center of a valve body of an intake valve and extending in a circumferential direction of each cylinder when a piston is at top dead center, as center height, and designating average of a height of the combustion chamber in a region outside from the virtual cylindrical surface when the piston is at top dead center, as peripheral height, the combustion chambers form a center height of a transmission side cylinder positioned most to the transmission side among the plurality of cylinders is higher than center heights of usual cylinders including one cylinder other than the transmission side cylinder and a peripheral height at the transmission side cylinder lower than peripheral heights of usual cylinders.

A cylinder block includes a support wall part that rotatably supports a crank shaft. The support wall part has a fitting recess part to which a bearing cap can be fitted. In each of the left and right corner parts where a bottom surface and a fitting surface of the fitting recess part intersect, a notch groove is formed that extends in the array direction of cylinder bores and has a substantially arc-shaped cross section when cut by the virtual plane along the extension direction thereof. As a result, stress having a greater value as the location becomes closer to the center part in the extension direction of the notch groove can be substantially uniform in the extension direction of said notch groove, and it is possible to effectively mitigate the stress concentration.

A support structure for a crankshaft includes a crankshaft that is rotatably supported on a cylinder block of an internal combustion engine and has an end portion protruding from the cylinder block, a sprocket that is attached on the end portion protruding from the cylinder block and is connected to a cam shaft, a pulley that is attached on the end portion on an opposite side from the sprocket with respect to the cylinder block and is connected to an auxiliary apparatus, and an end bearing that rotatably supports the end portion relative to the cylinder block and is provided on the end portion between the sprocket and the pulley.