Hello to You all. I have a simple question, i'm reparing my 1600cc (sp) engine from my 69 Bus, I'm gonna get new cilinders, pistons, ring's, etc. I've just removed my valves and i would like to know how a bad valve look's like. They are very black but i think that a good clean would just do it. Is there anything else that i should considerate to know if the valves are damaged? Thank's to You ALL.