What Are the Different Types of Piston Rings?

Video Transcript

"Okay, we've got a couple of pistons here. Actually, this is a piston in rod assembly out of a model T-Ford, and you can see that the rings by the way which are made out of cast iron and the piston is also cast iron are very, very thick; very large ring grooves. Again, the sealing was questionable and you also have the ring great gaps, the groove gaps that you can see. It's very important when you fit rings that you get the proper size ring and gap. Piston rings are made out of a, basically three different materials; cast iron. Most engines in the past are equipped with cast iron rings because they're least expensive to manufacture. They do a fairly good sealing job. They last a, a reasonable amount of time and cause very few problems. So some manufacturers provide chrome rings or chrome moly rings which are little more difficult to sit into a cylinder. In other words, get the rings to actually seal against any compression loss inside the cylinder. They require a, a little more precise installation and the cylinder will finish; it has, has to be a, a little more finer than what you would have on a cast iron sealing surface. So mostly chrome moly, there are some stainless steel rings, although not a whole lot; again, you want to have a material that can withstand high heat, temperature and pressure. So these rings live in a very very hostile environment inside the engine and they need for them to work well a long period of time. We don't see that much piston ring failure because of modern lubricating oils on engines and the much tighter tolerances that the modern engines are, have today and we don't see a whole lot of sealing washed like we used to or we used to have cars that were putting out that blue haze or smoke in the back which means that oil is getting pass the piston rings; it's just you know, not seen anymore. In fact, if your car is doing that, you'd probably not going to be driving it for too much longer because you're going to get pulled over and cited for something like that. We have a four B-6 engine here with the cylinder gaps have been removed and again you can take a look at the pops in the piston. It's actually, this engine; have some look; this is a commercial vehicle used for, for fleet service; probably hasn't been treated all that well. Very little carbon build up inside the cylinder so I'm sure, I'm sure it's high mileage; but you can see the cylinder walls over there and the tops of the pistons. We can't really show you the rings. Right here are the valve lifters and cam followers and right there on through the middle underneath, that's the cam shaft that pushes up on those cam followers which work on a push rod and push rod contacts a rocker arm and the rocker arm will tip open the valve. Again, if you're going to build a racing engine you might want to consider ring material; but for the most part, just a standard cast iron rings from a good quality manufacturers should suffice. In some instances, especially if you get a re-built engine, depending upon who the re-builder is, they have some very inexpensive re-builders piston ring sets that are pretty much generic and sometimes these don't last as long enough. You'll have to end up replacing the engine much sooner than you contemplated because of the poor quality of parts. Again, it's, you get what you pay for. If you want to get a brand new engine, a lot of brand new engines are available out there with good ring sets as well as re-manufactured engines and you could also have your own engine re-build. We do a custom re-build job for you and, and fit it perfectly."