Originally Posted by Danthurs
Valves burn when they don't close all the way. They need to seat to give off the heat, if not, they just get hotter until they burn. The valve could have been bent, or dirty causing it to stick. But $150 is a good deal for all the parts.
Right. I just did some more reading and found that even engine overheating could cause a valve to burn, and that 75% of a valve'* heat is dissipated when it touches the seal. If the seal is worn, it would have to be machined, which involves a valve job.
A low mileage pair of heads would be a lot easier than going through all that trouble.
Quick question while we're on the topic. I have 1.8 ratio roller rockers on this engine, and have been using stock valve springs. Should I have used stiffer valve springs?