Abstract: A hydrostatic camshaft phaser system includes a hydraulically-actuated camshaft phaser with a rotor; and a stator housing that receives the rotor and includes an advancing chamber and a retarding chamber defined at least partially by the vane; and a variable displacement pump, in fluid communication with the hydraulically-actuated camshaft phaser, comprising a first chamber in fluid communication with the advancing chamber and a second chamber in fluid communication with the retarding chamber; the first chamber receives fluid from a first non-continuous groove extending along a camshaft surface or a bearing surface and the second chamber receives fluid from a second non-continuous groove extending along the camshaft surface or the bearing surface during a first portion of camshaft rotation, and the first chamber receives fluid from the second non-continuous groove and the second chamber receives fluid from the first non-continuous groove during a second portion of camshaft rotation.