Abstract: A cylinder head assembly includes a cast cylinder head and a turbocharger housing integrally cast with the cylinder head. The integrated cylinder head and turbocharger housing includes: (i) a compact low wetted area to provide an uninterrupted flow path pointed directly at a catalyst face to facilitate achieving cold start emissions targets, (ii) a casting core assembly with specific core geometry and steps for assembly to enable core assembly while meeting all cylinder head and integrated turbine housing functional requirements, (iii) an oxygen sensor disposed pre-turbine in an integrated exhaust manifold, and (iv) a fully integrated PCV make-up air system.