Valve guide sizing is a crucial part of the head reconditioning.
An incorrect sized guide can cause the valve to seize if too tight, or cause premature valve seat wear and oil consumption if too loose. We use diamond hones that are preset to the exact size for each valve stem size.
Diamond hones give a perfect valve guide bore finish that is parallel.
We can also cut the final valve seat with diamond stones to give the ultimate seat in accuracy and finish.