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If It Takes A Piston Ring, We Can Build It



  • Axial tolerances of +/- .000050"
  • Improved sealing between piston and piston ringOptional PVD coatings engineered to match cylinder material and minimize friction losses
  • Custom axial thickness down to 0.6mm
  • Available in Gapless®, Conventional or Napier Styles

Why Diamond Finish?

A Ring’s Surface Finish Makes Power

To make power in any engine, there must be an effective seal formed around the piston during the compression and combustion stroke of any engine. Creating a seal between the cylinder wall and the piston is the main objective of the piston rings and the better the seal, the better the outcome on the compression stroke. This over-simplifies the 4-stroke process immensely, but the overall goal of minimizing pressure leakage past the top two rings is paramount to the performance of every internal combustion engine no matter what its use.

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How Total Seal Improved the Engine's Efficiency

There are three areas where leakage can be reduced when it comes to piston rings; the ring end gap, around the groove and between the face and the cylinder wall.

  • First is the ring end gap, which we addressed over 50 years ago with their gapless ring packs
  • A second area is the ring face to the cylinder wall which Total Seal has also refined with improved face surfaces and our gas ported rings.
  • The third is the seal between the piston ring and the ring land of the piston. This seal can be addressed with a focus on the surface roughness of the rings and is why Total Seal developed the Diamond Finish process.

Diamond Finish rings help reduce the path around the groove by sealing much better due to their smooth finish.

The smoother the ring surface, the less areas are available for high cylinder pressures to leak past the rings and into the crankcase. This effect, commonly referred to as blow-by, results in loss of efficiency in each cylinder effectively reducing the power of the engine. Total Seal’s Diamond Finish creates the smoothest finish of any piston ring, but to get a better idea of surface roughness, you need to think smaller. Very small

Think Microscopic

To really understand the importance of the surface of the ring, as well as that of the groove on the piston, you need to think microscopic. To help visualize the differences in ring surfaces, we’ll get help with Total Seal’s in-house profilometer. This advanced tool measures the peaks and valleys of any surface down to microns providing an up-close look at sealing deficiencies that can occur even on a well-built engine.

If you zoom in on the finish of a typical ductile iron piston ring, the surface looks like a sawtooth which results in leakage areas, albeit, tiny areas. When combustion pressures reach over 1500 psi, you can be sure those gasses are going to find any possible weak point and a standard ductile ring actually has many peaks and valleys forming leakage points. In the tests provided, you can see the results of a ductile iron ring compared to the surface of a Diamond Finish ring. Once you compare these variances next to each other, you really get an idea of how important the surface finish of the ring is for an effective seal.

Standard Finish

Diamond Finish

Added Performance Benefits

The number one goal of Total Seal’s Diamond Finish Rings is to increase the efficiency of the engine so it can produce as much power as possible and with improved piston-to-ring sealing, there are also other benefits. With improved ring sealing, the oil stays cleaner due to less blow-by occurring. Reduced blow-by can also help lower oil temperatures since less highly heated combustion gasses enter the crankcase of the engine. Lower oil temps combined with less contamination leads to longer oil life which over a race season will lead to budget savings!
Another side benefit of Total Seal’s Diamond Finish rings is their lightweight. The axial thickness of a Diamond Finish ring is held at +/- .000050-inch (that’s fifty-millionths of an inch) compared to a typical production ring which are about +/-.0005-inch. Less wight on each piston equates to less rotational mass resulting in improved acceleration of the engine. As an example, a typical .043-inch by .155-inch ring weighs 9.5 grams while a Diamond Finish .027mm ring weighs only 4.7 grams! Also, a thinner ring can conform to the cylinder wall better while also reducing friction as another way to improve the sealing and efficiency of an engine.
If a high performance race engine is in your future, there’s never been a better time to step up to a set of Diamond Finish rings as Total Seal now offers their premiere rings in sets! The Sets include a 0.8mm top and second ring paired with 3mm oil rings. If you these lightweight, thin rings aren’t in your wheelhouse, Total Seal offers their Diamond Finish on their gapless and ported rings and on rings up to 1/16”. For more information, contact the experts at Total Seal at 623-587-7400 or go to totalseal.com.

Engineering that works


Total Seal uses an advanced Profilometer to test and verify the surface roughness of our rings. This tool can measure variances in a surface down to 1-microm (one-millionth of a meter).

Results:  Ductile Iron

The peaks and valleys of this graph show the variances of a standard ductile iron ring surface measured in micrometers. Some measure +.1 spanning to -.2

Results: Diamond Finish

The same test shows the difference of the Diamond Finish surface. The variance is much smoother over the width of the ring which equates to a much more efficient seal to the piston ring land.