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 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.

In an internal combustion engine, an oil return passage extending from a breather chamber can be formed without increasing the number of component parts and without increasing the size of the internal combustion engine. 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 jointly with the engine block; a bearing member (50) fastened to the engine block in the crank chamber to rotatably support a crankshaft; a breather chamber (113) defined in the engine block; an inlet passage (112) formed in the engine block to communicate the crank chamber with the breather chamber; a connection pipe (114) communicating the breather chamber with an intake device; and an oil return passage (150) formed at least in the bearing member, and extending from a bottom part of the breather chamber to an oil return port (147) opening at an outer surface of the bearing member. The oil return port may be provided in a lower part of the bearing member.

An efficient internal combustion engine including a housing such as a cylinder block, cylinder covers and one or more pairs of working piston and auxiliary piston, moving in the working cylinder and auxiliary cylinder respectively. For each pair of working piston and auxiliary piston, the engine also has rods operatively connected to working piston and auxiliary piston, intake valve, operatively connected to the intake channel in the cylinder block, exhaust valve, operatively connected to the exhaust channel in the cylinder block, and two bypass valves located between the working cylinder and auxiliary cylinder. The engine also has a crankshaft that also functions as a camshaft, rod pushers for pushing special nozzles and valves, flywheel, Hydro-compensators and preferably a high pressure fuel pump (HPFP). No cylinder heads or separate camshafts are used in the present invention.tle

Improved internal combustion engine with a high-pressure fuel pump

Engines operating using multiple, different types of fuel are described. The engines may include components that control the introduction of fuels and/or reduce premature pre-ignition of fuels, such as a fuel comprising a percentage of hydrogen. The described hydrogen-fueled engines have a reduced carbon footprint.

An internal combustion engine includes a one-piece cylinder block casting, a flywheel supported for rotation at a front block end, and a back gear train supported for rotation at a back block end. Cast-in pump inlet and outlet passages are formed in the cylinder block casting and open in a pump mounting face at the back block end. An oil pump is clamped to the pump mounting face and includes a pump inlet and a pump outlet fluidly connected, respectively, to the cast-in pump inlet passage and the cast-in pump outlet passage.

A crankcase includes: a main body portion aligned with a drive motor in a direction perpendicular to a motor drive shaft; and an extended portion continuous with the main body portion and located lateral to a motor housing, the extended portion receiving insertion of one end of the motor drive shaft. A power transmission mechanism that transmits power from the motor drive shaft to an input shaft is located partly in a first region defined by the main body portion and partly in a second region defined by the extended portion and communicating with the first region.

An internal combustion engine includes a one-piece cylinder block casting, a flywheel supported for rotation at a front block end, and a back gear train supported for rotation at a back block end. Cast-in pump inlet and outlet passages are formed in the cylinder block casting and open in a pump mounting face at the back block end. An oil pump is clamped to the pump mounting face and includes a pump inlet and a pump outlet fluidly connected, respectively, to the cast-in pump inlet passage and the cast-in pump outlet passage.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber ignition system. In one example, a method may include determining amounts of pre-chamber gases in the cylinder prior to combustion, and adjusting an amount of fuel injected into the cylinder based on the amounts of pre-chamber gases in the cylinder. In this way, cylinder fueling may be compensated for additional air and/or fuel from the pre-chamber gases, which may increase an accuracy of the cylinder fueling and increase cylinder efficiency.

A method of selecting a compression ratio in an internal combustion engine having a mechanism configured to vary the compression ratio includes receiving, via an electronic controller, a requested output torque value. The method also includes determining, via the controller, a value of engine speed corresponding to the requested output torque value. The method additionally includes determining, via the controller, a compression ratio value corresponding to the requested output torque value and the determined value of the engine speed. The method also includes determining, via the controller, a position of the mechanism corresponding to the determined compression ratio value. Furthermore, the method includes commanding, via the controller, the determined position of the mechanism and thereby selecting the determined compression ratio value. A vehicle employing a variable compression ratio internal combustion engine and an electronic controller configured to operate the engine according to the method is also disclosed.