An engine is equipped with a gas feeding system, including main gas injectors each associated with an intake duct of a respective engine cylinder, a gas distribution manifold communicating with said main injectors, a gas tank, connected to the manifold, where pressurized gas is accumulated, a controlled pressure valve interposed between the tank and manifold, and a control unit for controlling the pressure valve to establish a gas pressure in the manifold. A spark plug of each cylinder is mounted within a support body that defines a combustion pre-chamber and a channel for auxiliary gas injection within the pre-chamber, communicating with a respective auxiliary gas injector. The auxiliary gas injectors are in communication with the manifold, downstream of the pressure valve. In the channel, a non-return valve and a restricted passage are provided in series, providing for passage of gas flow proportional to a volume of the pre-chamber.

The present disclosure relates to assemblies for engines such as pre-combustion chamber assemblies for spark ignition engines. In one example, a pre-combustion chamber assembly includes an ignition chamber adapted to contain at least one electrode of a spark generator. The ignition chamber being adapted to communicate with a main engine combustion chamber via a plurality of pre-chamber ports. The ignition chamber communicates for removal therefrom of exhaust gas residuals to a distinct storage chamber via at least one transfer port. The ignition chamber includes a single substantially cylindrical entrance channel leading from said pre-chamber ports in a direction towards an ignition region of the ignition chamber. The ignition region having a larger cross-section than the entrance channel.

An assembly is provided for a powerplant. This assembly includes a housing, a primary fuel injector and an ignition system. The housing forms a combustion volume within the housing. The primary fuel injector is configured to inject primary fuel into the combustion volume. The ignition system is configured to ignite the primary fuel within the combustion volume. The ignition system includes a pilot fuel injector, a pilot ignitor, a pilot chamber, a first component and a second component. The pilot fuel injector is configured to inject pilot fuel into the pilot chamber. The pilot ignitor is configured to ignite the pilot fuel within the pilot chamber. The pilot chamber is fluidly coupled with the combustion volume through an aperture in the first component. The pilot chamber is formed by and disposed between the first component and the second component. The first component is configured from or otherwise include a ceramic.

The present disclosure relates to assemblies for engines such as pre-combustion chamber assemblies for spark ignition engines. In one example, a pre-combustion chamber assembly includes an ignition chamber adapted to contain at least one electrode of a spark generator. The ignition chamber being adapted to communicate with a main engine combustion chamber via a plurality of pre-chamber ports. The ignition chamber communicates for removal therefrom of exhaust gas residuals to a distinct storage chamber via at least one transfer port. The ignition chamber includes a single substantially cylindrical entrance channel leading from said pre-chamber ports in a direction towards an ignition region of the ignition chamber. The ignition region having a larger cross-section than the entrance channel.