INTERNAL COMBUSTION ENGINE SYSTEM

A first intake manifold is connected to a first group of cylinders, a second distinct intake manifold is connected to a second group of cylinders and a first, respectively a second, exhaust manifold for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders. An EGR line is connected to the first and second exhaust manifolds. A mixing unit includes a four-way valve having a first inlet connected to an air line, a second inlet connected to the EGR line, a first outlet connected to the first intake manifold and a second outlet connected to the second intake manifold. The first inlet is connected to the air line, the second inlet is connected to the EGR line. The first outlet and said second outlet form a substantially X-shape. The first inlet and said second inlet are coaxial. The first outlet and second outlet are coaxial such that the first inlet is diagonally facing the second inlet and the first outlet is diagonally facing the second outlet.