Notable inventions throughout history, like, say, Teflon or Super Glue, emerged from the pursuit of other goals. Teflon was invented while NASA — the other one — was trying to come up with a coating for the nose of the space shuttle to withstand the heat of re-entry to earth’s atmosphere. Super Glue’s inventors at the Eastman Kodak company were initially attempting to make clear plastic gunsights for weapons used in World War II.
There are other examples of these “happy accidents,” such as penicillin, the microwave oven, the pacemaker and insulin. Those products have become so ubiquitous that it’s difficult to imagine modern life without them.
There is now another product relevant to car people, racers and rodders that also emerged in pursuit of other goals: ZyBar, a chemical high-temperature, heat-dissipating coating.
ZyBar is made by ZyCoat, a sister company to HushMat, the firm that manufactures sound deadening and thermal insulative material for a litany of applications, from muscle cars and hot rods to big rigs. According to ZyCoat and HushMat president Tim McCarthy, people had been approaching him for years to create a sprayable technology for sound deadening. And in 35 years, he never found a formula for sprayable sound deadening that worked as he thought it should, but he did come across a polymer used in the aerospace industry that caught his attention. Specifically, it was designed for use on the hot section of a gas turbine engine.
“I believe it was more of an insulate technology,” McCarthy said. “But during development, we were able to modify the polymers in a way that it created the heat dissipation value, the heat dissipation benefit.”
The product that eventually emerged after six and a half years of research and development is ZyBar, a sprayable coating that not only dissipates heat when applied to internal combustion engine components, but also improves performance on the dyno. We’ll get to that in a bit.
Dissipation, Not Containment
McCarthy initially started down the path toward a ceramic-like technology, but depending on humidity, and a number of different variables, ceramic chemistry, and its reaction can be unstable. He cites one particular story from the R&D process.
“We were going down a path, and we were still kind of on the ceramic-based technology, and I had about 5 gallons of product produced and put in metal paint cans, and it was Friday afternoon. I said, ‘Hey, just set those on the conference room table. I’ll come in Monday and I’ll deal with them,’” McCarthy said. “I work every weekend. I came in over the weekend, and in my infinite wisdom, I went into the conference room and I looked, and the paint cans looked like pumpkins. And, like an idiot, I took a screwdriver and I opened one of them, and I just about blew the windows out of my conference room and the blinds were shaking, and it was like, OK, back to the drawing board because we’re not doing this. It took us in a little different direction. Let me just say that.”
The modified polymer — that’s all McCarthy will divulge about its chemical makeup — that emerged from the R&D process is proprietary chemistry. The Zybar safety data sheets don’t give much detail, either, but McCarthy said ZyBar has a pencil hardness greater than ceramics, which transition to glass at around 650 degrees Fahrenheit, at which point it becomes brittle.
What’s notable and different about the ZyBar coating process is that it works best when it’s applied to the outside and the inside of an exhaust header to prevent radiant heat from accumulating in the metal. In cured form, the coating is only 40 to 50 microns thick. For reference, one micron is equivalent to one thousandth of a millimeter, so 50 microns is just five one-hundredths of a millimeter. Here’s why you want it inside and out.
“What our product does is prevent the metal substrate from absorbing heat,” McCarthy said. “If you think about the inside of a header tube, you have radiant heat that presses in across the entire 360 degree (circumference) of that tube. And that’s what’s happening if you wrap a header or if you put a blanket over it. It’s trapping that heat, and that heat and that metal has nowhere to go other than it penetrates to the inside of the header. It actually increases the surface temperature of the metal through heat absorption. Now, you have created, instead of a two and a half inch tube, might be (effectively) 2.4 inches in diameter. And that flow area is restricted, and what occurs is it increases back pressure. What our coating does is it allows that heat to penetrate through the metal and dissipate, and it doesn’t radiate inside the tube. So you’ve now opened up that entire two and a half inch diameter for flow.”
Radiant heat inside exhaust tubing restricts flow. That has been true of every header and exhaust component that’s ever been built, McCarthy said. Header wraps and ceramics are insulative. As impossible as it seems for a coating applied to the inside and outside of a header, ZyBar is heat dissipation technology. That microsurface technology penetrates into the metal through fissures, microscopic cracks, pores and voids, which allows the metal to transfer heat at an accelerated rate.
By just coating the outside, you get radiant benefit on the outside for underhood temperatures in the surrounding area, but you’re not getting performance benefits that come with coating the inside.
ZyBar improves cylinder scavenging through reduced back pressure, is corrosion resistant and performs at up to 2,000 degrees Fahrenheit without turning brittle. It’s lightweight and works in a number of applications, including headers, tailpipes, mufflers and manifolds. McCarthy also said they have coated the hot side of a turbocharger and its downpipe, and found spool times reduced by 25 percent.
For dyno testing, ZyCoat sent a General Motors small-block crate 604 engine to Karl Kustoms in Ankeny, Iowa, along with four sets of identical Lingenfelter headers. One set was left stock, one was coated inside and out with ZyBar, one was ceramic coated and the other was covered with header wrap. ZyBar not only reduced radiant and surface temperatures, but also increased in horsepower and torque.
“So, we saw 150-some pulls that we did at a third party. We saw a very consistent improvement in torque and horsepower versus any other treatment versus stock headers,” McCarthy said. “And it was uniform. It wasn’t like we saw one pull and said, ‘Oh, let’s choose that one.’ It was really consistent on every pull that had our coating, especially on the interior of that tube.
“We’ve got a tremendous amount of data that’s been generated,” McCarthy added. “We’ve got dyno testing that really corroborated a lot of our bench chemistry theory. And now we’ve got real world turbo data. We’ve got it in really several different fuels. Diesel, we’ve got it in alcohol, we’ve got it in nitro. We’ve got it in several different classes now, and the product is performing extremely well.”
The Top Fuel team ZyCoat worked with, Terry McMillen Racing, said that ZyBar reduced the upper and lower bandwidth of temperature on its headers by about 100 degrees Fahrenheit. That gave the team a more predictable curve on EGTs. The headers also cooled more quickly, which allowed the team to start between-heat teardowns sooner. In addition, the team used to run ceramic-coated headers, which they would have to refurbish or replace after 15 runs due to fracturing. When they coated the headers with ZyBar, they were getting more than 60 runs on a set.
“So, we kind of fell into it relative to understanding what was happening, relative to back pressure, temperature with EGT summaries and seeing the relationship of horsepower and torque,” McCarthy said. “We pretty much confirmed that is exactly what’s happening in the inside of a tube. And yeah, this is now beyond, I’m not a dyno technician. I’m not a poly chemist. However, when you tie all those variables together that the picture became, I won’t say clear — it took us seven years to derive it — but that technology has been proven.”
We conducted a bit of an experiment on a 2.5-swapped MX-5 used for competition in NASA TT5. We measured the No. 2 primary tube on the stock header with the factory catalytic converter and registered 573 degrees at idle at operating temperature. We sent ZyCoat a new header without a catalytic converter and had it treated with ZyBar. Under the same conditions, from the same distance using the same tool, we measured 535 degrees on the No. 2 primary tube.
It’s not exactly apples to apples, but it was pretty convincing data that the ZyBar reduced temperatures on a car that really can benefit from reducing under-hood heat. For the money, it seems like a no brainer. So, how much does it cost?
Well, more than doing nothing and more than header wrap, but comparable to that of ceramic coating. For V8 applications, figure $800 to $1,000 depending on their complexity, and about $400 to $600 for four- and six-cylinder engines. You’ll also have the expense of shipping to ZyCoat in Olathe, Kan., unless you can find a coater local to you.
“Our end goal is to have a couple hundred coaters around the country that are applying our product,” McCarthy said. “We don’t want to compete against them, but right now we’re kind of having to until we get that full network built out.”
You can coat components that already have been used, but you’ll need to pay to have them cleaned so the ZyBar will adhere. If you have the right equipment, you can apply the coating yourself, but McCarthy recommends professional application. ZyBar does cure through air drying, but it’s best to have it oven-cured so you don’t chip any of the coating off during installation. Once the header is in and the car has been run up to temperature, the ZyBar self cures. But if you ever have installed headers, you understand they don’t just drop in unscathed. There’s usually a bit of banging and clanging.
“It’s an air-dry and oven-cure product. We oven-cure 100 percent of everything that we do. And the reason for that is that with oven cure, you can bolt it on and go,” he said. “You can spill brake clean on it and go. If you air cure it, it doesn’t have its chemical resistance and hardness until it sees that elevated temperature.”
As exciting as it is to get more power, there were other benefits, such as when a late model driver was relieved that her feet weren’t getting hot anymore. They also have used ZyBar on exhaust in marine applications, and even on intake manifolds. Still in its infancy, ZyBar has the potential to be a disruptive technology in managing heat and achieving power gains.
“Given where we are today and the end result, it’s really cool,” McCarthy concluded. “It’s not often that you can stumble upon a breakthrough like this, and I truly believe it’s breakthrough, and the data has proven it.”
