Integral PCV system

An internal combustion engine, comprising:

• an engine block having a crankshaft housed in a crankcase portion of said engine block, cylinders defined by cylinder walls for housing pistons, a coolant jacket adjacent to said cylinder walls defining a coolant passage through said engine block to transfer heat from said cylinder walls to coolant flowing therethrough, a cylinder head mounted on an upper surface of said engine block with a head gasket interposed therebetween, said cylinder head having an intake port to receive intake charge and an exhaust port for each of said cylinders, an intake manifold including an intake plenum to distribute intake charge to intake runners, aligned with said intake ports, and a PCV system including an oil separator, labyrinthine in structure, to separate oil from blowby gas accumulating in said crankcase portion and having a first chamber with an opening to said crankcase portion, a second chamber adjacent to and stepped up from said first chamber, an upper transfer passage between said first and second chambers to transfer blowby gas therebetween, and an oil drainage conduit for draining separated oil from said second chamber to said first chamber, a third chamber adjacent to and stepped up from said second chamber, a lower transfer passage between said second and third chambers to transfer blowby gas therebetween and for draining oil from said third chamber to said second chamber, and a gas outlet from an upper end of said third chamber, wherein said chambers of said separator are formed integrally within said engine block and adjacent said coolant jacket to transfer heat from said coolant passage to said blowby gas, said PCV system further including a PCV passage formed integrally within said cylinder head wherein an aperture in said head gasket regulates flow of blowby gas from said separator to said PCV passage which delivers blowby gas to said intake manifold.