Oil pump pressure relief valve layout

A pressure relief valve, comprising:

• a valve housing having an inlet end with an inlet opening having a valve seat surface surrounding the inlet opening, an outlet end with a plurality of separate outlet holes and a valve chamber disposed between the inlet end and the outlet end, one of said plurality of separate outlet holes having a smaller cross section than remaining ones of said plurality of separate outlet holes;
• a valve member disposed in the valve chamber and biased toward the valve seat surface by a spring member that is disposed against the outlet end;
• wherein the valve chamber has a base diameter and includes a plurality of separate radially protruding grooves extending radially beyond the base diameter and extending axially from the valve seat surface to the outlet end, one of said plurality of separate radially protruding grooves having a groove cross section that is smaller than a groove cross section of remaining ones of the plurality of separate radially protruding grooves.