Pull the valve cover and check for bent pushrods. Most engine noises can be diagnosed with a little detective work. Unless it sounds like there are a bunch of little guys with sledgehammers in the crankcase trying to pound their way to freedom, running the engine long enough to get to operating temperature probably isn't going to do much more damage. How far did the engine manage to rev up before you got it under control?
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!