Often you can detect foreign junk in the cylinder by looking at the spark plug -- the electrodes get hammered to hell.

Getting the part out via the plug hole would have been a challenge, however. Makes you wonder: If the clamp could get past the intake valve, why couldn't it get past the exhaust valve?

This is a good lesson for us all, unfortunately at your expense. When working on the engine, remember to carefully plug any ports into the engine to prevent dropping that little screw into an inaccessible spot.

And remember to unplug all those same places during reassembly.....
--
Don Foster (near Cape Cod, MA)