11 Now use your feeler gauge to check the gap. You can’t put material back onto the ring, so you want to sneak up on the final gap size in several steps. Here, you can see the gap is only 0.014-inch. We’ve got a way to go to get to 0.022, but we’ll get there slowly to make sure we don’t overshoot the mark. Once you get the gap correct, place the ring in an envelope marked with its correct cylinder until you are ready to install it on the piston and the piston in that hole.