Induction system with orientation means for directing gases tangentially to the swirl motion

The head (10) has two inlet pipes (14, 16) extending from inlet orifices to outlet orifices (20, 24). The pipes are arranged so that gas flow forms a swirling movement around a major axis (A) of a combustion chamber. Each outlet orifice has an edge including a notched portion (32) which extends on an arc situated in downstream of a major axis (C) of the outlet orifices, in relation to the swirling movement.