Internal combustion engine with methane injection system

Internal combustion engine with a methane feed system having compression ignition, said system having a plurality of methane injection devices respectively associated with the various cylinders of the engine and mounted within respective seats communicating with a common distributing conduit or rail for feeding methane, and wherein the seats for the injection devices and said common distributing conduit are formed in an auxiliary body separate from the intake manifold and the head of the engine,

• said engine further comprising an electronic control unit which provides for controlling the injection devices on the basis of signals indicative of the parameters of operation of the engine, so as to carry out the injection of methane into each cylinder, at least when the rotational speed of the engine is lower than a predetermined threshold, with the intake valve of said cylinder already opened, and
• wherein said auxiliary body is interposed between the intake manifold and the engine head and conduits for passage of the air fed to the engine are formed through it, which communicate the cooperating conduits formed in the intake manifold and the engine head to each other, said auxiliary body further having a plurality of methane outlet holes which are aligned with said seats for the methane injection devices and respectively communicate with said conduit for passage of the air formed in the auxiliary body.