Race industry online performance parts platform, EPARTRADE has been delivering the informative weekly Race Industry Now  webinar series for over five years. Many are moderated by famed announcer, Jeff Hammond. In a recent episode (#532), the EPARTRADE team and Jeff bring back one of their very first guests, Jon Kaase of Jon Kaase Racing Engines to discuss his use of a revolutionary abradable piston coating offered by Line2Line Coatings. In this article we’ll recap parts of the webinar and dive deeper with Line2Line President, Andy Suman to understand the science, benefits, and how it works. Read on to discover why over 15,000 job shop orders have been placed for pistons finished by Line2Line Coating.

What Is Abradable Powder Coating and How Does It Work?

Abradable Powder Coating (APC) is a self-polishing plastic-and-graphite finish added to functional parts. Various resins are used for strength, thermal, and chemical reasons. During break-in, it wears into the shape of the mating surface to improve fit, efficiency, and durability. “It is applied by a powder coating process,” says Suman. “We are very careful to measure properly and coat to dimension. We want enough meat on the parts so they find their own fit during initial operation.”

The abradable piston coating is applied to the skirt with tight tolerance to the bore. The coating feels “fuzzy” when fresh, but during initial break-in sweeps it quickly wears to create a polished fitment of the piston in the bore. Numerous tiny cavities are left behind that effectively stabilizes oil film and reduces the oil volume the rings must handle. The coating’s final shape is achieved at temperature, under load. “Building it tight used to scare folks away,” continues Suman. “Now it’s commonplace because so many have experienced stable, self-fitted piston/ring performance.”

Creating an improved piston fit over a greater bore area also helps reduce secondary lateral vibration int he rotating assembly as well as preventing the rocking of the piston ring assembly against the cylinder wall. By keeping the piston square to the bore it reduces ring friction and wear.

Abradable powder coating on pistons is a game changer and requires a different approach in the engine build processes. “Builders used to want the pistons before honing. We prefer honing first, getting the actual bore size, and coating to near bore size,” says Suman. The self-polishing process during break-in takes it from there.

Line2Line Coatings offers several variations including Slick CC, Slick+, and TriboLiv Series. The differences relate to the strength and hardness that balances the properties for a quick break-in with durability for the life of the component. According to Suman, “Jon Kaase and 90-plus-percent of the [motorsports] pistons get Slick+. Small, low-power, or vintage engines may get Slick CC so you can go tight and not cause drag, long term. Top Fuel and Funny Car engines gets TriboLiv”

Race Proven Experience With Abradable Piston Coating

How do pistons with Line2Line Coatings abradable piston coating hold up at the racetrack? For that, EPARTRADE and Line2Line Coatings welcomed longtime client and champion engine builder Jon Kaase to the webinar.

“I was kind of born skeptical,” says Jon Kaase in the episode. “Ain’t no way they can do this kind of stuff… But, I like the idea of it, if it works; it sounded really good to me.” In true Jon Kaase Racing Engine fashion, they put it up to a big test. “On the big engines, our piston speed is around 8,400 feet per second. It’s got a 5-3/4-inch stroke, and we run them to 8,600 rpm, so they’re really grinding away in there. You end up with a really big window at the bottom of the bore where the rod swings through. So when the piston gets to the bottom, it’s not very happy because there’s not much holding it in; it almost exposes the oil ring. So the tighter you make [the piston skirt] down there, the better.”

In Kaase’s testing, the coatings perform as advertised, and then some. “We’ll run a set of pistons for a whole year now, maybe 100 runs,” says the former Engine Masters’ Challenge champion. “We’ll put three sets of rods through the motor, and we won’t touch a piston again, So they take a lot of abuse on these big engines. They’re 2,000 horsepower motors.” Kaase continues to show a well-run Pro Stock piston and shows how the abradable coating on the piston skirt holds up.

When asked in the episode what to expect and if there’s a need to change the oil after initial break-in, Suman explains, “We’ve never heard of any problems with the particles coagulating anywhere. One thing is that the coating needs a little bit of friction to wear in. So if you start off with super synthetic oil it may take longer to break in. Also, if you have a super-polished bore, that can make it take longer to wear in. If you think about it, some of the assembly lubes have particles in them — you know moly or probably Teflon — so these little tiny particles of graphite function like those particles. You can break in an engine and run that oil to the full length of the oil’s life, and it will look dark, but there’s nothing wrong with it.”

What Other Parts Can Abradable Powder Coating Be Used On”

Line2Line Coatings handles more than just pistons. According to company literature, APC can be applied to timing gears to reduce noise and pump gears to improve efficiency. In superchargers, it improves volumetric efficiency and on bearings it provides scoring protection. “On new applications, we always inform the customer when they are entering R&D land. We don’t make false promises, but we will coat anything that fits in the ovens!” remarks Suman. Line2Line Coatings encourages feedback and works closely with their family of engine builders. “Feedback from end-users is priceless. We use it, learn, improve our products, and help future customers,” concludes Suman.

While the webinar is a little lengthy, we suggest you carve out some time to watch it start to finish, as there is some good information shared by folks that make four-digit horsepower every day of the week.