An internal combustion engine includes a crankcase with a plurality of piston-cylinder arrangements and a valve head positioned above the crankcase at least in part containing a valve train. The internal combustion engine further includes a head cover coupled to the valve head and having a blowby outlet and a baffle positioned between the head cover and the crankcase and defining an oil passage internal to the baffle. Engine oil circulates through the oil passage of the baffle to transfer heat to blowby gas flowing from one or more of the plurality of piston-cylinder arrangements before exiting the valve head through the blowby outlet in the head cover.