Pipe bender

I was always told it was bad on the valves to run them with open or headers for extended periods of time. I've never understood it but it was one of those things I heard in trade school that stuck with me lol

Yeah, if you do it over and over and over and over again, maybe. I'd drive that beeotch right on up there. What's the difference between that and 20 minutes worth of break in?