Pre-chamber of internal combustion engine

The present disclosure relates to a pre-chamber assembly (20) for an internal combustion engine, and a related method. The pre-chamber assembly (20) may comprise a main pre-chamber body (22) including a main pre-chamber (36), and an auxiliary pre-chamber body (32). The auxiliary pre-chamber body (32) may comprise an auxiliary pre-chamber (42) and at least one flow transfer passage (44) fluidly connecting the main pre-chamber (36) and the auxiliary pre-chamber (42). The auxiliary pre-chamber body (32) may further comprise a fuel supply channel (46) opening in the auxiliary pre-chamber (42). Thus, if combusting lean fuel air mixtures, the pre-chamber assembly (20) may facilitate a high ignitability while generating a small amount of nitrogen oxides only.