A peristaltic piston pump driven by a dedicated pump cam disposed on a camshaft
of an engine. A plurality of valve-opening cams are disposed along the camshaft.
The pump cam has a plurality of lobes equal in number to the number of valve cams
and each pump lobe is disposed at 180 from a valve cam lobe such that the
camshaft valve torque and secondary oil pump camshaft torque partially cancel,
reducing overall camshaft torque oscillation. The pump includes a lost-motion shuttle
and spring to permit continuous response of the pump to the cam.