An ic engine intake duct having a bent baffle plate

An intake system for an ic engine comprises an intake duct 20' and a rotatable bent baffle plate 24', which has a curved portion 22', mounted on a spindle 30' and movable between a first position, for low load operation, where the plate obstructs the majority of the duct 20' except for a small area 26' formed between the duct wall and the curved portion of the baffle 22' and a second position, for high load operation, where the baffle 24' does not restrict the duct 20' (figure 2b). Preferably the wall of the duct 20' may have a recess 21' so that the wall does not restrict rotation of the curved baffle portion 22'. The plate 24' may have perforations to allow a supplementary air flow to be created across the width of duct 20'. Additionally the baffle may be placed as close as possible to the valve port at the end of the duct to minimise the volume of gases that may be stored between the baffle and the port and into which fuel, and/or exhaust gases for an EGR system, may be introduced.