OHC Engine Valves

There are several different methods of adjusting the valves on an overhead cam (OHC) engine. Many are adjusted like mechanical lifters in a pushrod engine.

The rocker arm adjuster is turned until the correct size feeler gauge fits between the rocker or cam lobe and the valve stem.

Valve adjusting shims may also be used on OHC engines for the cam-to-valve clearance. To determine whether shims are required, measure the valve clearance with a feeler gauge. Then, if needed remove or change the shim thickness as necessary.

Other OHC engines have an Allen adjusting screw in the cam followers. Turning the screw changes the valve clearance. Always refer to the manufacturer’s manual for detailed instructions.