Abstract: An exhaust silencer has an inlet opening and an outlet opening spaced axially from the inlet opening and includes a cylindrical shell. A core inside the shell defines at least one axial passage and has at least one helical baffle defining a helical flow passage around the axial flow passage within the shell. The axial flow passage has a barrier at its downstream end and has an upstream opening aligned with the silencer inlet opening. It also has an outlet axially spaced from the axial passage inlet opening, the said outlet being directed transversely outwardly into the downstream half of the helical flow passage, at a region upstream from the barrier.