ISX CAM BEARING FAILURE
ISX Cummins DOHC heads are often return with an injector cam bearing seized to the camshaft. The cause is twofold: 1) When the technician removed the camshaft on the head exchange, they stood the camshaft on end. Since the camshafts are hollow, all of the oil ran out. 2)Upon installation, the engine must be pressure primed with the valve cover off to observe oil seeping out from between the cam and the bearings. The predominant cam bearing seizure is on the injector cam because four of the bearings do not have oil holes in them to pressure lubricate the cam and bearings. If the pressure lubrication process is not followed, it is almost certain a failure will occur.

Arvid Elbeck
American Cylinder Head
Oakland, CA
January, 2017