Methods and systems are provided for injecting fuel into a combustion chamber of an engine. In one example, a system may include a hollow cone-shaped injector and a control unit to control the injector. The control unit may detect the position of an inlet valve and trigger the injection process, wherein the injector may be configured to spray fuel out of an inlet duct, through an annular gap, and into the combustion chamber of an engine in an injection process.

A motorcycle includes a supercharger to pressurize an intake air and supplying it to a combustion engine and an air intake chamber disposed downstream of the supercharger. The air intake chamber is made of a metallic material and has a capacity of an interior space thereof which is within the range of three to eight times the displacement of the combustion engine. The dimension from an upstream end portion on an inlet side of the interior space of the air intake chamber to a downstream end portion on an outlet side of the interior space of such air intake chamber is chosen to be three or more times the inner diameter of an outlet.

A secondary fueling system for a diesel internal combustion engine includes an injector which injects an oxygen-containing secondary fuel into the engine's air intake system, a pump which pumps the secondary fuel to the injector, a sensor which senses pressure in the air intake system, and a secondary fuel controller which receives output signals from the sensor and pump, operator inputs for the engine, and data signals pertaining to operation of the engine from the main engine controller, determines an injection amount of the secondary fuel based thereon, and controls the pump based on the determined injection amount. A position of the injector in the engine's air intake system is distant from the engine's intake valves and is based on the engine's displacement, e.g., it relates to approximately equal to one quarter of the engine's displacement.

An air intake chamber is disposed at a location downstream of a supercharger and upstream of a throttle body. The air intake chamber serves to accumulate an intake air pressurized by the supercharger. This air intake chamber includes a confronting portion, which has an outlet and overlaps the throttle body, and a connecting portion that connects between the confronting portion and a discharge port of the supercharger. The connecting portion has an outlet side opening set to be larger than an inlet side opening thereof.

An engine assembly includes a cylinder head having an intake side and an exhaust side opposite the intake side. The cylinder head has an intake port, an exhaust port, and a combustion chamber in fluid communication with the intake port and the exhaust port. The engine assembly further includes a port fuel injector coupled to the cylinder head. The port fuel injector is disposed closer to the exhaust side than to the intake side of the cylinder head. Further, the port fuel injector is fluid communication with the intake port to allow fuel to be injected directly into the intake port. The engine assembly further includes a direct fuel injector coupled to the cylinder head. The direct injector is in fluid communication with the combustion chamber to allow fuel to be injected directly into the combustion chamber.

Apparatuses, systems, and methods are disclosed to produce HHO gas in a pressure-resistant container for use in an internal combustion engine to increase fuel efficiency and/or reduce emissions, for example by introducing the HHO gas to one or more air intake ports of the engine.

An off-road vehicle includes an internal combustion engine, a supercharger, an intercooler, an intake tank, a throttle body, first injectors, and at least one second injector. The engine includes cylinders. The supercharger supplies intake air to the engine. The intercooler is provided at an intake conduit provided between the supercharger and the engine. The intake tank is provided at the intake conduit and defines an intake chamber inside the intake tank. The throttle body is provided at the intake conduit, and includes intake conduits and throttle valves. The intake conduits are respectively connected to intake ports of the cylinders. The throttle valves are respectively provided in the intake conduits. The plurality of first injectors are provided at the throttle body and inject fuel to the respective intake conduits. The at least one second injector is provided at the intake tank and injects fuel to the intake chamber.

An engine control device controls control amounts of a variable valve mechanism and a spark plug, the control amounts in a homogeneous lean operation region set in a first load region are different from that in a non-lean operation region which is a stoichiometric or rich operation region set in a second load region higher than the first load region. The control device performs control, in other operation region set in a third load region between the first and second load region, so that an air-fuel ratio of the internal combustion engine is equal to that of non-lean operation region, the control amount of the variable valve mechanism is equal to that of homogeneous lean operation region and the control amount of the spark plug is equal to that of the non-lean operation region in accordance with an operation amount of an accelerator pedal.

A gaseous fuel feed apparatus includes a first injector and a second injector which are provided in each cylinder of a gas engine. The first injector injects a gaseous fuel into an intake passage. The second injector injects the gaseous fuel in an injecting direction intersecting with an injecting direction of the gaseous fuel injected by the first injector, such that the gaseous fuel injected by the second injector collides with the gaseous fuel injected by the first injector. Thus, the gaseous fuel injected by the first injector can be forcibly pressed toward a flow of an air by utilizing an injection energy of the gaseous fuel injected by the second injector. Further, the first injector and the second injector may be placed at the same position of the intake passage, and can be placed at a position of the intake passage that is adjacent to a combustion chamber.

An engine assembly includes a cylinder head having an intake side and an exhaust side opposite the intake side. The cylinder head has an intake port, an exhaust port, and a combustion chamber in fluid communication with the intake port and the exhaust port. The engine assembly further includes a port fuel injector coupled to the cylinder head. The port fuel injector is disposed closer to the exhaust side than to the intake side of the cylinder head. Further, the port fuel injector is fluid communication with the intake port to allow fuel to be injected directly into the intake port. The engine assembly further includes a direct fuel injector coupled to the cylinder head. The direct injector is in fluid communication with the combustion chamber to allow fuel to be injected directly into the combustion chamber.