Imperial size valve seat inserts are supplied for customers using pre-set cutters that will machine a nominal size counterbore. The interference fit is on the valve seat insert, i.e. The counterbore is a nominal inch size and the interference is already added to the valve seat insert.
Metric valve seat inserts are size as listed, and therefore the counterbore needs to be that size less the interference fit.
All valve seat inserts we supply are suitable for unleaded fuel. We can also supply valve seat inserts suitable for LPG or heavy duty applications.
We can undertake to manufacture small batch or production quantities of valve guides or valve seat inserts. We supply many manufacturers of cylinder heads and as such your cylinder head may already contain our product. This does not stop us producing a small quantity to your specification.