Damaged valve

[andrewjscott]

What would cause this a valve to do this (see below, sorry for the poor quality). It happened while I just driving up a hill and all of a sudden felt a miss. I ran a compression test and only had 20 PSI on cyl 2. The engine was rebuilt about 7k ago and ran smoothly since then.

 

[Scott_S]

You burnt a valve buddy. That is caused by either the valve margin is to small or the vavle face wasnt seating properly

 

[andrewjscott]

Well now i'm really disapointed. I had the valves cut at a machine shop, and they assembled the head...they'll be hearing from me.

 

[andrewjscott]

one other thing I forgot to mention, there is a bit of a score in the cylinder wall, noticeable to the eye, but barly noticeable to my fingernail when i run it accross. The score starts about 1/2 way down and continues to the bottom of the stroke. The piston appears to be in perfect shape. Am I gonna have to pull the bottom end apart?