Methods and systems are provided for detection of cylinder misfire in an engine. In one example, a system may comprise a first cylinder and second cylinder of the engine having exhaust flows combined together in an exhaust system before being combined with other cylinders of the engine. The first cylinder and second cylinder may share an exhaust gas sensor mounted in the exhaust in a position to sense exhaust from the first cylinder and second cylinder, and being positioned before exhaust from other cylinders is combined with sensed exhaust from the first cylinder and second cylinder. The system may further include a control system with instructions stored therein to indicate detected misfire in one or more of the first and second sensors based on an output from the exhaust gas sensor.

An engine is provided with a cylinder liner that extends beyond the surface of the crankcase surrounding the cylinder. When the engine is oriented in an inverted V-block configuration, the extension of the cylinder liner provides a barrier to oil that can pool on the crankcase surface and otherwise enter the interior of the cylinder, absent such a barrier.

An engine is provided with a cylinder liner that extends beyond the surface of the crankcase surrounding the cylinder. When the engine is oriented in an inverted V-block configuration, the extension of the cylinder liner provides a barrier to oil that can pool on the crankcase surface and otherwise enter the interior of the cylinder, absent such a barrier.

An intake structure of the present invention is applied to a multi-cylinder engine including an electrically controlled throttle integrally including a throttle valve configured to adjust an amount of air to be supplied to the engine and an electronic control unit configured to control the throttle valve. The engine intake structure includes: an air cleaner configured to purify the air; and an intake manifold configured to distribute the air purified by the air cleaner to an intake port of each cylinder of the multi-cylinder engine. The electrically controlled throttle is attached to the intake manifold such that the electronic control unit is separated outward in a radial direction of an engine rotation shaft.

An intake structure of the present invention is applied to a multi-cylinder engine including an electrically controlled throttle integrally including a throttle valve configured to adjust an amount of air to be supplied to the engine and an electronic control unit configured to control the throttle valve. The engine intake structure includes: an air cleaner configured to purify the air; and an intake manifold configured to distribute the air purified by the air cleaner to an intake port of each cylinder of the multi-cylinder engine. The electrically controlled throttle is attached to the intake manifold such that the electronic control unit is separated outward in a radial direction of an engine rotation shaft.

A system and method are provided for an internal combustion engine. An engine system, in one example, includes a cylinder liner positioned within an opening of a crankcase, including a surface biasing a landing surface of an undercut fillet of the crankcase, and including a cylinder opening and a seal arranged in a groove of the cylinder liner positioned axially above the undercut fillet. The engine system further includes a fluid gasket and a combustion gasket positioned between a cylinder head and the crankcase, the fluid gasket and the combustion gasket being decoupled from one another.

A system and method are provided for an internal combustion engine. An engine system, in one example, includes a cylinder liner positioned within an opening of a crankcase, including a surface biasing a landing surface of an undercut fillet of the crankcase, and including a cylinder opening and a seal arranged in a groove of the cylinder liner positioned axially above the undercut fillet. The engine system further includes a fluid gasket and a combustion gasket positioned between a cylinder head and the crankcase, the fluid gasket and the combustion gasket being decoupled from one another.

An internal combustion engine includes a crankshaft that is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a V-type arrangement in which the cylinders are disposed above a virtual horizontal plane including a rotational axis of the crankshaft and intersect each other at a bank angle, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that is mounted from an outside at a position, lower than the virtual horizontal plane, of a front face of the crankcase that receives air flow, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thereby provided is a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision in a so-called V-type internal combustion engine.

A system and method are provided for an internal combustion engine. An engine system, in one example, includes a cylinder liner positioned within an opening of a crankcase, including a surface biasing a landing surface of an undercut fillet of the crankcase, and including a cylinder opening and a seal arranged in a groove of the cylinder liner positioned axially above the undercut fillet. The engine system further includes a fluid gasket and a combustion gasket positioned between a cylinder head and the crankcase, the fluid gasket and the combustion gasket being decoupled from one another.

A system and method are provided for an internal combustion engine. An engine system, in one example, includes a cylinder liner positioned within an opening of a crankcase, including a surface biasing a landing surface of an undercut fillet of the crankcase, and including a cylinder opening and a seal arranged in a groove of the cylinder liner positioned axially above the undercut fillet. The engine system further includes a fluid gasket and a combustion gasket positioned between a cylinder head and the crankcase, the fluid gasket and the combustion gasket being decoupled from one another.