How To Install Piston Rings

In this video, the Moss Tech department goes over piston ring installation and covers the importance of spacing the gap in the rings around the piston.

Before we can put our new rings on our pistons and put them inside our cylinders, there are two things we have to do.

First we have to check the ring gap. If this is done incorrectly or not done at all, rings can get broken. When the ring is inside the cylinder, this gap is made very small. We need to know just how big that gap is. Take the ring and put it inside the cylinder and then take a piston and push down about an inch or so. That will put the ring nice and level. Find in your shop manual how big of a gap there should be. Get your feeler gauge and set it to that. Reach down the cylinder wall and feel the gap. If the gap is too small, this ring will get broken or damaged. We can’t have that. If it is too small, get a file, put it in a vice, and put the ring on either side and file it down a bit. Take a few thousandths off of it if you have to. Put it back in, use the piston to straighten it out and check it again. Sometimes every one of these is perfect and no work is necessary. Sometimes you have to do them all. The main thing is that you’ve checked it and you know that it’s right.

When you’re done and the ring gap is good, see how the ring goes on the first groove on the piston and you see there is a small gap on the edge. What we don’t want is the gap from the second ring and from the third ring to be in a line. You want to stagger them. If the ring gap is good and you’ve staggered the rings, everything is going to be fine.