In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

A method for operating an internal combustion engine, which has at least one combustion chamber, at least one intake valve associated with the combustion chamber, and at least one injector associated with the combustion chamber, includes injecting fuel directly into the combustion chamber by the injector in order to operate the internal combustion chamber, where at least one partial stroke of the injector is performed while the intake valve is open.

Methods and systems are provided for adjusting engine operating conditions for mitigation of pre-ignition in one or more engine cylinder. In one example, a method may include, in response to indication of pre-ignition, manifold charge cooling may be increased by increasing the portion of fuel delivered to the engine via manifold injection relative to the portion to fuel delivered via one or more of port and direct injection, while maintaining engine operation at or around a stoichiometric air-fuel ratio.

Methods and systems are provided for adjusting engine operating conditions for mitigation of pre-ignition in one or more engine cylinder. In one example, a method may include, in response to indication of pre-ignition, manifold charge cooling may be increased by increasing the portion of fuel delivered to the engine via manifold injection relative to the portion to fuel delivered via one or more of port and direct injection, while maintaining engine operation at or around a stoichiometric air-fuel ratio.

In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

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.

In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

An outboard motor includes a crankshaft, a first bank including a plurality of first cylinders, a second bank including a plurality of second cylinders, a plurality of first injectors, a plurality of first spark plugs, a plurality of second injectors, and a plurality of second spark plugs. Each of the first and second cylinders includes a combustion chamber, an intake port, and an exhaust port. The first injectors and the first spark plugs are alternately disposed in a vertical direction. The second injectors and the second spark plugs are alternately disposed in the vertical direction in a reverse order to that of the first injectors and the first spark plugs. When the crankshaft is seen from a horizontal direction, the first cylinders and the second cylinders are disposed symmetrically about a point of symmetry arranged on an axis of the crankshaft.