Patent ID: 8113160

Claim:
A camshaft phasing system for an internal combustion engine, having an engine block, a crankshaft rotatably mounted in the engine block, a cylinder head and engine valves, the phasing system comprising: first and second camshafts for operating the engine valves, the first camshaft having a plurality of axially extending channels therein; a phaser mounted on the first camshaft having an input rotatably coupled to the crankshaft, a first output coupled to the first camshaft, a second output driving the second camshaft, and oil feeds in fluid communication with at least some of the plurality of channels; first and second control valves for applying oil under pressure to the phaser via at least some of the plurality of channels in the first camshaft, to enable the timing of the first and the second camshafts, respectively, to be varied independently with respect to the engine crankshaft; wherein the first camshaft is hollow and the axial channels in the camshaft are defined by a separate insert fitted inside a hollow first camshaft.