Conforming to pressure may often be looked at as a sign of weakness or compromise. In engines, compromise is a necessary evil that engine builders strive to minimize. From ignition timing to fuel curves, component strength or weight savings, it’s a never ending trade off in terms of compromises in order to gain overall performance.
However, conforming to pressure takes on a completely new discussion when it comes to sealing the cylinder, and the experts at Total Seal Piston Rings take conforming very seriously. Piston rings have one of the toughest jobs in an engine as any leakage past the rings results in an inefficiency that not only diminishes the power of the engine, but also degrades the ability of the motor oil to properly lubricate. Total Seal has the answer on how best to conform to (cylinder) pressures.
When it comes to a better ring seal, not only does the engine become more efficient through the four strokes of the engine, but less combustion gasses leaking into the crankcase means the engine oil stays cleaner longer. Clean oil and cooler oil protect the engine better, which increases oil life and the longevity of the engine itself.
Total Seal offers the Total Conform rings in AP Steel and with their top line Diamond Finish, depending on the application and use of the engine. Total Conform rings can be made from either stainless steel or tool steel, depending on the demand of the application. Due to these variances, it’s best to call one of Total Seal’s tech experts to discuss the engine build to ensure the best ring possible for the build.
The cylinders of all engines experience some form of localized distortion due to heat, head bolt positions and sleeve materials. The best example to illustrate these differentiations is to use a big bore, long stroke engine. The temperatures at the top of the cylinder are higher than the temps at the bottom of the cylinder which leads to different rates of expansion. This example is especially prevalent in thin sleeve aluminum blocks as the materials expand unevenly under temperature changes.
When cylinder distortion occurs, it causes leakage points between the piston rings and the cylinder wall. Piston rings are typically designed to seal a round cylinder, so any distortions to the cylinder can cause gaps between the cylinder and the rings leading to increased blow-by. Put simply, a loss of efficiency.
Due to this physics of these alterations, the piston ring would need to change the shape of the outer diameter as the engine operates. While a traditional piston ring design allows for some conformability, there’s just no way it change shape enough to seal as effectively as the cylinder bores distort due to heat, pressure and mechanical stresses. Or is there? Total Seal now offers a solution with their Total Conform top rings.
The Total Conform Ring is a unique design for the top compression ring. The patented ring has a series of radial notches around its inner diameter which allows the ring’s outer diameter to shift its shape, allowing it to conform to the distortions in the cylinder wall. This radiused form reduces stress risers as well as the chance of the ring fracturing while maximizing its ability to conform to the ever changing cylinder form to produce a more effective seal.
Joe Gibbs Racing recently performed a test of the Total Conform rings on an iron sleeved, aluminum block developed for an off-road race truck. The engine featured a wide bore and used Total Seal’s .8 mm Diamond Finish rings as the base line for the test. When fitted with a Diamond Finish Total Conform ring (also .8 mm), the engine produced 50% less blow-by! Where there is blow-by, there is lost power and a 50% reduction is substantial in any engine.
The form shifting abilities of the Total Conform ring was designed to seal in combustion pressures, but their design also resulted in a lighter and more flexible ring. The radial notches of the ring also provide an area where cylinder pressures can push the ring out to assist in sealing to the cylinder wall much like a gas ported ring.