What are the experiences here with the Black Diamond valves?
In the /2 world, they have a poor reputation of head separating from stem when used hard (as hard as a /2 can use its valves, that is). A few years ago there was a guy who attempted to ride an R69S in the Iron Butt, but had this problem on the second day.
I realize that the situation inside a roller bearing crank, low volume oil pump motor could be very different than inside a "modern" plain bearing, high pressure motor.