I did eventually destroy that same engine.....from running it too cold. It was my test mule engine and had a very hard 2 year life. Eventually I tried adding an extra head shim and I couldn't get heat to build in it, so I foolishly kept the rpms up trying to warm it up. Crank-pin broke. Had another engine that decided to go WOT on start-up (always check other peoples work!) and before I could stop it, the rod broke. Running a cold engine at WOT is probably the next worst thing to running an engine so lean there isn't enough lubrication. But as said, merely being hot isn't so bad....it's if the heat is coming from lack of lubrication. That's why I usually adjust my top end just short of screaming. If it sounds like it wants to blow up, it just might.