You mean to say, that I can't just take a head off and look it over? I can
test it......
before taking it off and it will save time? So, your saying that you shouldn't just take stuff apart to "see what's going on"? Who'da thought.......
I think it's cool you mentioned the drill press with the valve. I've done that so many times....... Hate to say it on here, but for valves that I didn't have the tools to grind (too small) I've actually taken a whetstone and "ground" them on the drill press. Wasn't pretty, but it did work.
(Yes, I know, I know.... but for what it was, and the fact it made it run.... that's all I needed.)
Note: Not a suggested method to others!!