Patent attributes
The present invention comprises an oil system for supplying and controlling oil flow in an internal combustion engine having a variable camshaft timing (VCT) device, comprising a pressurized oil supply providing lubricating oil to the engine and the variable cam timing device and an oil circuit connecting the oil pump with the VCT and a main oil gallery of the engine via a valve apparatus. The valve apparatus responds to oil pressure near the outlet of the oil pump so that oil flows to the main oil gallery when oil pressure is above a predetermined pressure. When the VCT requests oil flow, oil pressure in the system drops. If the pressure drops below the predetermined pressure, the valve apparatus causes a reduction in flow to the main gallery.