Valve Seat / Guide Valve Seat Inserts Valve Seat Inserts can be fitted to correct a slightly faulty head and we also use them for converting cars onto unleaded fuels from leaded fuels. Read More Valve Seat Cutting Valve Seat Cutting is usually necessary on a head when simple pressure testing and skimming will not do. This usually means damage has been done because of the extra valve travel and this the seats will need precision re-cutting. Read More Porting and Polishing After any cutting has been carried out the ports must remain completely in-shape and smooth and polished to aid smooth flow throughout and the head is then put back into our washer for a final clean before re-assembly. Read More