andytwo

In the process of rebuilding a CNC'ed prepared head with a supertec seats, springs and retainers.

Anyone know if the OEM (Part 12-116A which seems constant across the years but for some reason appeared absent on my donor head) seat is retained and the supertec simply placed over the top as the Supertec catalog suggests the possibility the OEM plus the supertec seat being retained?

Or is the thickness of the OEM seat incorporated into the supertec seat so it can be deleted.

With the Supertec seat only in situ plus the valve stem seal the seat is free to move up/down by about 1-2mm which seems strange as I suspect with the OEM in place this play maybe taken up.

Any information appreciated.