An intake device of an engine having cylinders is provided. The intake device includes a cylinder head formed with two intake ports per cylinder, and a forced induction system. One of the two intake ports is designed to have a smaller passage cross-sectional area at a throat portion thereof than that of the other intake port, and to cause a strength of a tumble flow strength of intake air formed within a combustion chamber to be stronger when a flow of the intake air into the combustion chamber is assumed to be caused only from the one of the two intake ports, than only from the other intake port. A tumble ratio of the intake air flow within the combustion chamber is a predetermined value or greater when the intake air is forcibly induced and flows into the combustion chamber from the two intake ports.

Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

An outboard motor includes a cylinder block, a cylinder head unit, a delivery pipe, a plurality of injectors, a fuel pump, and a fuel pipe. The cylinder block includes a plurality of cylinders. The cylinder head unit is connected to the cylinder block. The delivery pipe is attached to the cylinder head unit. The injectors are attached to the delivery pipe. The fuel pump is attached to the cylinder head unit. The fuel pipe is attached to the delivery pipe and the fuel pump. A first attachment direction of attaching the fuel pump to the cylinder head unit is parallel or substantially parallel to a second attachment direction of attaching the fuel pipe to the delivery pipe.

A cylinder block including: a plurality of cylinders; a cylinder head attached on the cylinder block and including, for each of the cylinders, an intake port extending from a combustion chamber upward and obliquely relative to an axis of the cylinder; a direct injector disposed at a position on an outer side of the intake port in a cylinder radial direction and directly injecting fuel into the combustion chamber; a port injector disposed at a position on a same side as the direct injector relative to the intake port, and injecting fuel into the intake port are provided. The intake port includes: a valve seat provided at an intake air inlet opened to the combustion chamber; and an arc portion protruding downward in a center area of the intake port on an upstream side of the valve seat, and an injection direction of the port injector is orientated in a direction in which the fuel injected from the port injector passes through a lower area of the arc portion.

An object is to improve the combustion condition in an internal combustion engine equipped with a supercharger and performing diesel combustion using fuel having a relatively high self-ignition temperature in an operation state in which the engine load is increased or decreased. A control apparatus performs first injection during the compression stroke, causes spray guide combustion to occur, and starts to perform second injection at such a second injection time that combustion of injected fuel is started by flame generated by the spray guide combustion, thereby causing self-ignition and diffusion combustion of fuel to occur. During a response delay period in changing the boost pressure when changing the engine load of the internal combustion engine to a target engine load, the ratio of the quantity of fuel injected by the first injection to the total fuel injection quantity in one combustion cycle is made higher than the ratio of the quantity of fuel injected in the first injection to the total fuel injection quantity in one combustion cycle during the time when the engine load is equal to the target engine load and the actual boost pressure is equal to a target boost pressure corresponding to the target engine load.

An engine system capable of controlling an intake air flow includes a combustion chamber, an ignition plug, an intake air flow control valve, and a controller. The controller performs, in at least a part of an operating range, SPCCI combustion in which after jump-spark ignition combustion of a portion of a mixture gas inside the combustion chamber by a jump-spark ignition of the ignition plug, compression ignition combustion of the remaining mixture gas is carried out by a self-ignition. The controller strengthens, at least in a part of the operating range of SPCCI combustion, the intake air flow inside the combustion chamber by controlling the intake air flow control valve. The controller controls, in a middle-load range of the operating range where SPCCI combustion is performed, the intake air flow control valve so that the intake air flow becomes weaker than in a high-load range and a low-load range.

The invention relates to the technology of gasoline direct injection (GDI) in automotive engines. In this context, the invention provides a method for maximizing the formation of deposits in injector nozzles of GDI engines, said method including at least one test cycle, each test cycle including at least one testing step in which a predetermined condition of speed and load of the GDI engine is maintained for a specified period of time, wherein, in said cycle, in at least one testing step, the engine speed is maintained between 1300 and 3700 rpm, the engine load is maintained between 10 and 80% and the specified period of time is from 10 to 200 minutes. Thus, the method of the invention is able to reproduce severe conditions of deposition of material in a few days, so that, in a short period of time, the test fuel can be assessed for tendency to form deposits.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.

A hydrogen intake assembly for a hydrogen internal combustion engine characterized in that the hydrogen intake assembly includes at least one air intake manifold comprising an air intake pipe comprising at least one air inlet and air outlets, air intake runners comprising air inlets and air outlets, a spacer having a wall defining an inner chamber receiving a mixture of air, water and hydrogen and comprising air inlets and mixture outlets delivering said mixture, a water rail comprising at least one water inlet and water outlets, said water outlets being embedded in the wall of the spacer and a hydrogen rail comprising at least a hydrogen inlet and hydrogen outlets.

In one aspect, an engine ignition apparatus for a natural gas engine may include a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine. In another aspect, an engine ignition apparatus for a natural gas engine may include, among other features, a controllable valve connected to a hydraulic fluid chamber, and configured to open and release a hydraulic fluid from the hydraulic fluid chamber, and to close. In still another aspect, a method for controlling an engine ignition apparatus for an engine includes, among other features, controlling a volume of a hydraulic fluid chamber of an ignition apparatus.