After grinding a valve, how can you correct tappet clearance that is too small?

When grinding a valve, it is common for the tappet clearance—also referred to as valve clearance—to become too small due to the material that has been removed from the valve face. If the tappet clearance is too small, the lifter may not have enough space to properly release pressure, potentially leading to valve damage or improper engine function.

The correct action to take in this scenario is to grind the end of the valve stem. By grinding the end of the valve stem, you effectively shorten the valve stem length which increases the tappet clearance. This adjustment ensures that the valve can fully seat without undue interference from the rocker arm or tappet, maintaining optimal engine performance.

Other options would not adequately address the issue. Installing a new valve may not solve the problem if the same clearance issues persist, and adjusting the rocker arms could lead to further complications or inadequate adjustments. Loosening the valve seat is not a viable solution as it could compromise the integrity of the valve seating surface and lead to additional mechanical issues. Therefore, grinding the end of the valve stem is the most appropriate and effective method to correct tappet clearance that is too small after valve grinding.