Adjustable vane in combine harvester

An improved processing system for a combine harvester having a rotor housing that concentrically receives a rotor used for threshing and separating grain in crop materials, the processing system comprising a plurality of concave and/or separator grate assemblies arranged side-by-side axially along the processing system, the rotor housing comprising a cover to direct flow of crop material through the rotor housing around the rotor, the improvement comprising at least one adjustable vane configured to guide crop material through the rotor housing extending from an inner surface of the cover, said vane having a curved shape such that a cover-facing proximal edge of the vane is in close proximity to the cover and an exposed distal edge projects away from the cover toward the rotor, wherein a leading end of the vane is connected to the cover by means of a first pivot connection and said vane is connected to the cover along said proximal edge with a second pivot connection, wherein the first pivot connection is positioned closer to a front end of the cover than the second pivot connection such that a line drawn through the first and second pivot connections intersects a plane perpendicular to an axis of the cover, said line forming an angle with the plane of between about 5 and 15 degrees, wherein said vane pivots with respect to the cover about a pivot axis along said line defined by the first and second pivot connections to adjust a tilt angle of the vane and wherein tilting the vane adjusts an angle of the distal edge of the vane relative the plane perpendicular to the cover axis.