We were looking for a specific problem, an annoying overheating situation on a round track race engine. We found a tiny pinhole in a cylinder wall near the bottom of the piston travel. When we bored the block to sleeve that cylinder the pinhole turned into a pocket of trapped casting sand that had been barely nicked when we bored the engine .030" oversize and bumped the horsepower to 600+ at 7200 RPM. Chances are it would never have shown up in a standard-bore street engine.
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!