Abstract: An internal combustion engine cylinder assembly includes a coin insert disposed at the top end of the cylinder acting as a firing deck. The coin insert is formed of a super alloy material and is situated within a recess defined in the cylinder head. A radial clearance is provided between the cylinder head and the coin insert to allow for thermal expansion during engine combustion. In one embodiment, the coin insert is welded to the cylinder head at a location immediately adjacent the fuel injector to directly transfer injector and combustion loads through the insert into the cylinder head. In a second embodiment, a coin insert is welded to an injector sleeve which is disposed within the injector bore of the cylinder head between the cylinder head and the fuel injector. The injector sleeve includes an upper ledge disposed from the injector opening through which loads are transmitted from the coin insert into the upper part of the cylinder head.