This massive metal particle was found clunking around in the cylinder of a large propulsion ship engine in port in the Persian Gulf. Apparently a valve rod seized up in its guide. This locked the valve to the “open” position. As the piston traveled down in the exhaust stroke, it hit the valve and knocked it off. As the engine continued to run, the valve bounced around in the cylinder rounding it into the fist-shaped particle seen in the picture. Sure wouldn’t want to see anything like this plop into my sample bottle!
Submitted by Jim Fitch, Noria Corporation
