one of my RAVE valve and housing is worn down enough that exhaust gases from slipping past the housing and melting the piston cap.

I'm so cheap that I was thinking of wrapping a small piece of Aluminum tape around the valve where it is worn down, just enough to fill in the gap, but still allow the valve to slide up and down.

Do I need to grease the valve housing where the valve makes contact, right near the bellow?