Over the past few years, coating technology has become very apparent in the automotive performance industry. Nowadays, it’s not uncommon to see coated pistons, piston skirts, rings, bearings, combustion chambers, and even intake and exhaust components. But did you know that piston rings are another area that can be coated for better performance and offer lower friction, more extended life, and fewer emissions? While coatings seem to be all the rage, Total Seal Piston Rings has found that gas nitriding is a very useful process with advantages as well.  

While at the 2021 PRI Show, we ran into Lake Speed Jr., vice president of sales and marketing at Total Seal, to see what was new in the world of piston rings. “Gas nitrided expander rings.” Speed continued, “The expander in a three-piece oil ring is actually a spring because the oil rings do not have tension. We had 3/16-inch oil rings in the old days, which had about 21-pounds of oil ring tension. Since then, the OEM has gone to a thinner oil ring package for fuel economy and better seal; they got smaller and smaller. The standard tension with a two-millimeter ring is now about nine pounds. The problem is, the expander is a spring, and as you use it, it will lose tension, causing oil retention problems.”

In this image, you can see the black nitrided oil expander on the left and the standard one on the right.

Total Seal Gas Nitrated Ndurance Oil Ring Features:

• Increased performance and endurance
• Zero to minimal distortion 
• Precise dimensional control
• Improved wear and corrosion resistance
• Increased fatigue strength
• Extended life
• Added abrasive wear resistance
• Enhanced surface lubricity

While you might think that Total Seal came up with new materials or designs to cure this problem, the solution was much more straightforward. “By nitriding the oil expander, we gain three-four pounds of tension. So now, a two-millimeter ring has as much tension as a three-millimeter. Even more important is that the nitriding process changes the metallurgy; It doesn’t lose any tension over time.”

For more information on Total Seal gas nitrided oil rings and other innovative products, be sure to visit Totalseal.com.