An engine start abnormality diagnosis apparatus determines a cause of a long cranking abnormality in which, when an engine including cylinders is started, start of the engine is not completed even if a cranking period is equal to or greater than a predetermined time. The engine start abnormality diagnosis apparatus includes a rotation speed detector and an abnormality diagnosis processor. The rotation speed detector detects a rotation speed of a crankshaft of the engine when at least one of the cylinders is in a latter stage of a compression stroke. The abnormality diagnosis processor determines that the cause of the long cranking abnormality is an electric system abnormality when the rotation speed is less than a predetermined threshold, and determines that the cause of the long cranking abnormality is a combustion abnormality when the rotation speed is equal to or greater than the threshold.

Control is performed so as to occur SPCCI combustion in which, after an air-fuel mixture in a first area of a combustion chamber that includes an electrode portion of an ignition device is burned by receiving ignition energy, an air-fuel mixture formed in a second area located on an outer periphery of the first area is self-ignited. Control is also performed such that, in a high load operation region of an SPCCI combustion execution region, an air-fuel ratio in the entire combustion chamber becomes richer than a stoichiometric air-fuel ratio and that an air-fuel ratio of the air-fuel mixture in the first area becomes leaner than an air-fuel ratio of the air-fuel mixture in the second area.

An engine system may include an intake line, and a cylinder deactivation (CDA) device selectively deactivating a portion of combustion chambers in the engine. The engine system may further include a first exhaust manifold connected to a first plurality of combustion chambers mounted with the CDA device, a second exhaust manifold connected to a second plurality of combustion chambers without the CDA device, a first exhaust line connected to the first exhaust manifold, a second exhaust line connected to the second exhaust manifold, and a third exhaust line connected with the first and second exhaust lines through an exhaust gas processing device. In addition, a turbocharger including a turbine is mounted at the first exhaust line and rotated by exhaust gas. An air injection device may supply air to the second exhaust manifold or the second exhaust line in a catalyst heating mode of the exhaust gas processing device.

Embodiments for operating an engine having parallel turbochargers and two fluidically coupleable, separated intake manifolds is provided. In one example, a method includes responsive to a first condition, operating a first cylinder group of an engine, deactivating a second cylinder group of the engine, and blocking fluidic communication between a first intake manifold coupled to the first cylinder group and a second intake manifold coupled to the second cylinder group, and responsive to a second condition, activating the second cylinder group and establishing fluidic communication between the first and second intake manifolds.

A structural frame is provided. The structural frame includes a bottom surface, first and second cylinder block sidewall engaging surfaces, the first and second cylinder block sidewall engaging surfaces positioned above the bottom surface at a height that is above a centerline of a crankshaft support included in a cylinder block when the structural frame is coupled to the cylinder block.

An internal combustion engine includes one or more unopposed cylinder units where each cylinder unit drives the crankshaft via a yoke assembly rather than a conventional connecting rod. The yoke assembly is formed by a connecting rod assembly that can have an upper portion having a connecting member connected to the piston, and a lower portion. The connecting rod assembly moves exclusively along the bore axis of the cylinder, with no side to side motion. The connecting rod assembly also defines a transverse slot in the yoke portion in which a connecting rod bearing housing reciprocates with motion of a connecting rod journal on the crankshaft within the transverse slot. Since the motion of the connecting rod is linear, and the connecting rod bearing housing moves circularly, there are no secondary forces resulting in an inline engine using the unopposed cylinder unit configuration.

A common-rail fuel injection device for an internal combustion engine, including fuel injection valves each having two fuel supply ports, is known as a fuel injection device for suppressing temporary decrease of a fuel pressure immediately after the end of fuel injection from the fuel injection valve. Even in this fuel injection device, the fuel injection pressure may fluctuate immediately after the end of fuel injection, thereby causing changes of amount and particle diameter of injected fuel. A common rail is connected to one fuel supply port of the fuel injection valve, whereas another fuel injection valve, which is non-contiguous in the order of combustions, is connected to the other fuel supply port by an injection-valve connection pipe.

A structural frame is provided. The structural frame includes a bottom surface, first and second cylinder block sidewall engaging surfaces, the first and second cylinder block sidewall engaging surfaces positioned above the bottom surface at a height that is above a centerline of a crankshaft support included in a cylinder block when the structural frame is coupled to the cylinder block.

A water jacket for a cylinder head includes: an upper body disposed at an upper part of the cylinder head inside the cylinder head and through which a coolant flows; a lower body disposed under the upper body inside the cylinder head and through which the coolant flows; and a connector disposed corresponding to a position of an exhaust valve between the upper body and the lower body and integrally connected to the upper body and the lower body. Tt least one penetration hole is formed in the connector along a length direction.

A supercharged engine is provided, which includes an engine body having cylinders, an intake passage disposed outside the engine body and connected to the cylinders via intake ports, a supercharger provided in the intake passage and spaced apart from an intake-side side surface of the engine body, the intake-side side surface being connected to the intake passage, and a fuel pump disposed on the intake-side side surface. A portion of the intake passage constitutes an intervening part located between the supercharger and the engine body. The intervening part overlaps with the fuel pump in one of vertical and lateral directions of the engine body.