What makes piston ring selection and ring endgap so important to engine life and power? What's more, what makes that first engine firing so critical to proper break-in and longevity? Those first few minutes an engine runs sets the stage for power, efficiency, and engine life. In an ideal world, all engine builds would include a dyno pull for proper engine break-in. However, if you're like most of us you can scarcely afford the engine build let alone the added expense of a dyno session. On the dyno, an engine builder gets to load the engine and lean on the throttle hard to seat piston rings and bearings, which is more challenging to do on the open road.
For more information, please visit Dongya.
However, engine break-in is getting ahead of our story. Piston and ring selection is where it begins. Before we get into piston ring types, we need to talk about what piston rings do. Though the job of piston rings is obvious—cylinder sealing and oil control—another equally important function is carrying heat from the piston to the cylinder wall via direct contact. Oil also carries destructive heat away. As piston rings have become thinner for friction reduction, efficiency, and more power, heat transfer from piston to cylinder wall has become more critical and decidedly harder on pistons.
If you're planning high-performance driving, piston ring selection is as critical as piston selection. Selection depends upon how your engine will be used. There are three basic piston types: cast, hypereutectic, and forged. Cast pistons tend to be old-school and were original equipment in most cars and trucks back in the day. Hypereutectic pistons are high silicon cast—chosen for their hardness and cost. They don't cost much more than cast and they're more durable. Forged pistons are very rugged and can withstand a lot of abuse. They're the only choice for high-performance applications. The downside to forged pistons is expansion rate. They require greater piston-to-cylinder wall clearances because they employ aggressive expansion rates. As a result, they're noisy on cold-start with a very predictable rattle that gives way to quiet as the engine warms.
Ring width is the first consideration in ring selection, which depends on how you intend to use your engine. If you're going racing or conducting a fuel economy challenge, you want thinner piston rings, which create less friction and consume less energy. More conventional piston ring dimensions (wider) are appropriate for weekend cruisers and daily commuters because they wear better and carry greater loads. You're going to get more life out of them.
Back in the day, standard ring packages were a 5/64-inch top compression and secondary rings followed by a 3/16-inch oil ring package. These dimensions apply to a ring's thickness. The 5/64-inch thickness (0.078-inch) called for a significant amount of pressure against the cylinder wall for proper sealing. Piston ring manufacturers call this radial tension. The downside to this is friction. The most friction in any piston ring package is created by the oil rings. However, the combined friction of all three rings is significant. It robs the engine of power and efficiency.
Automotive engineers eventually realized a thinner piston ring package would reduce internal friction and improve efficiency. Factory engines came with a 1.5mm/1.5mm/3.0mm piston ring package beginning in the s for reduced friction. As piston rings have become thinner, the amount of radial tension required to seal it against the cylinder wall is greatly reduced. This occurs because as we reduce the total surface area of the ring touching the cylinder wall, the radial tension can be reduced to produce the same amount of load on the ring.
By reducing radial tension on the cylinder wall with a thin piston ring, we're also reducing friction generated as the ring rides against the cylinder wall. We improve power by reducing internal friction in multiple cylinders. It can also be safely said thinner piston rings seal better, which means blow-by past the rings (lost power) is reduced. This means more cylinder pressure (heat energy) is captured above the pistons, rewarding us with greater sums of power. Little by little, the aftermarket performance industry has been offering us a greater selection of piston and ring combinations.
Total Seal piston rings from Summit Racing Equipment offer a greater lineup of thin, low-friction ring packages for the progressive engine builder, with Ultra-Thin Advanced Profile series piston rings with 0.9mm top and second rings with a 2mm oil ring. According to Summit Racing, replacing a typical 1/16/1/16/3/16-inch thin-ring package with the Total Seal Ultra-Thin 0.9/0.9/2mm combination reduces internal friction by as much as 90-percent. It is this advanced ring technology that gives us both performance and efficiency.
Contact us to discuss your requirements of Piston Ring Manufacturer. Our experienced sales team can help you identify the options that best suit your needs.
Advanced piston ring technology does not come cheap. Total Seal's Classic 1/16-inch ring set from Summit for a 4.030-inch bore costs just over $100. Total Seal Gapless Secondary rings cost just under $400 per set. Ring spacers run costs even higher at nearly $500.
For performance applications, it is more about choosing the proper piston configuration and compression ratio along with selecting an optimized ring package. This must first begin with the selection of the right ring material. Ring widths and type can be chosen once the material has been selected. JE Pistons, as one example, offers a huge selection of ring materials, which at first can be overwhelming. First iscarbon steel, which is a much more malleable material than traditional cast iron and can handle higher temperatures without losing temper and is better able to withstand detonation.Cast iron, by its very nature is brittle and not as strong as hardened forged steel. Hardened steel top rings perform so well that even automakers are using more of them these days in production engines for durability. Steel makes more sense if you're planning boost, nitrous, or excessive amounts of compression because it tolerates the extremes better than iron.
Chrome-facedwere popular at one time, but have lost favor and aren't used much anymore by engine builders. The problem with many chrome-faced rings was they were extremely hard and difficult to break-in due to their hardness. What's more, they didn't handle detonation very well. It is suggested you not use them.
Some rings are offered with a tough plasma molybdenum coating in addition to gas nitride for durability.Steel nitridetop rings are a good choice for performance applications, however, are not always optimum because they can be expensive. JE Pistons offers a great many ring options if you're on a budget.Hardenedis a good option for street performance engines and a step up from traditional cast iron with magnesium added to the grey iron to improve ductility because ductile iron is more flexible. It is less likely to break. In fact, ductile iron is roughly twice the tensile strength of grey iron and flexes instead of breaking when subjected to high stresses. This makes ductile iron a terrific top ring when you're concerned with cost. JE Pistons tells us ductile iron rings are offered with a plasma molybdenum (moly) face coating to make them more compatible with iron cylinder walls.
JE Pistons adds itsPremium Racering pack is a great example of a ductile iron top ring that uses the more modern plasma-moly inlay technology, which produces an extremely hard, porous, wear-resistant surface that retains oil and improves lubrication while at the same time reducing internal friction. The plasma is applied by spraying the ring with an alloy powder containing Chromium, Molybdenum, and Nickel along with other elements into a small channel in the ring face. Using extreme heat, powdered metal turns into a molten spray that offers adhesion characteristics that reduce the potential for flaking and failure. This approach means faster break-in and better cylinder sealing.
The second piston ring doesn't deal with the intense heat and pressure the top ring does. JE Pistons tells us its Plasma Moly ring package is an excellent choice calling for a carbon steel nitride top ring with a ductile iron second. A less expensive version of this combination is theSportsman Seriesring package that involves a plasma-sprayed ductile iron top ring combined with a grey iron second ring, which is a more affordable ring package.
Oil rings in the third groove are simpler, with most ring packs offering carbon steel for the two sealing rings. The expander in the middle of the two rings may vary but the main question you want to ask yourself is—how will the engine be used? Once you've made your ring material selections, you can move on to the next level of decision making in terms of top and second ring design, face styles, radial thickness, and perhaps any special treatments such as lapping and/or ultra or critical finish steps. This entire process is all aimed at optimizing ring seal and capturing cylinder pressure above the piston where it can be translated into power.
If you're looking to save money and aren't going racing, Summit Racing Equipment and Speedway Motors offer a broad selection of Speed Pro cast, hypereutectic, and even forged pistons for virtually every Detroit-born engine out there. Hypereutectic pistons are a nice compromise over forged and cast if you're just going cruising. Summit's tech staff can advise you best on what to select along with just the right ring package for the piston you have selected.
If you want to learn more, please visit our website Motorcycle Piston Rings Suppliers.