12/18/2020
Saw this on a group post.
When you are purchasing valves, especially ones that are custom and you are going to wait to receive, it is always advisable to have moly start and end locations handy.
This picture is of another manufacturers "quick-turn-around" line where one-size-fits-all. The two-piece valve "blank" is machined and molybdenum is plasma sprayed to a length that will accommodate almost every valve size.
Moly is used on titanium valve stems to keep them from galling in the guide. It's porosity aids in providing lubricity by holding the right amount of oil.
In many, if not all cases, we see delamination happen.
Victory, through decades of experience and learned know-how builds 100% custom one-piece forged valves to order, in most instances quicker than any other supplier. Victory 1 stocks hundreds of valve combinations that will NEVER put your groove into the moly.
In conclusion it is imperative that when you order Titanium valves (that are not fully coated with CrN) that you have the following dimensions before you order valves:
Moly Start Position (Distance from Combustion Face of valve to valve guide when valve is closed) This dimension is critical and gives us the information needed to keep moly out of the port and away from the valve groove.
Request that your moly coating stop well below the groove and start in the right position to keep it out of the port.