The variable valve timing mechanism includes a housing, a rotor rotatably supported within the housing, and a lock pin. The housing includes a plurality of fluid chambers one of which includes a lock bore. The rotor includes a central portion and a plurality of vanes extending radially from the central portion. Each of the vanes extends into the fluid chambers of the housing to define an advanced fluid chamber and a retarded fluid chamber. One of the plurality of vanes includes a pin bore. The lock pin includes a shank section and an insertion section. The insertion section includes a nonlinear outer side profile. The lock pin is slidably received within the pin bore between an unlocked position and a locked position in which the insertion section of the lock pin is received within the lock bore of the housing thereby prohibiting relative rotation between the housing and the rotor.