Late-night pitchman Ron Popeil coined the phrase “set it, and forget it” when he was promoting one of his many inventions from the past few decades. While that notion may be just fine for a rotisserie chicken or a roast, it’s not exactly the best advice for your automobile. If you’re truly an enthusiast, you’re going to be under the hood tinkering with something sooner or later – even if it isn’t necessary. For us, there’s a different catchphrase: “forget it, and regret it.”
Most of us know we have to open the hood and do a good visual inspection. However, one area that doesn’t get much attention after the installation is complete, is exhaust headers. They get installed and essentially ignored unless you hear that ticking sound indicating an exhaust leak. If you choose to reduce underhood temperatures, you might even decide to put a thermal wrap on your headers. Like many other controversial topics, you can find many who are for wrapping them up, and just as many who are against it.
Rather than just sharing our opinion on the matter, we decided to reach out to the experts on both sides of this topic to find out what they say about wrapping headers. Our goal is not to start a debate to see who’s right or wrong, but to come to an understanding and give you the best advice from the experts: Moroso Performance Products and Design Engineering (DEI). We also reached out to one of the better known names in exhaust headers: Hooker.
Header wraps aren’t just for looks, they’re functional when installed properly. But it doesn’t stop there. Just like the vital fluids that keep your engine and transmission functioning properly, a header wrap also requires some level of maintenance and monitoring. If you use the same principle mentioned above – set it and forget it – you just might end up with more problems than solutions. First, let’s look at the different types of header coatings and what to expect once you wrap them.
Exhaust Headers And Header Coatings
When it comes to exhaust, Holley’s Hooker brand has been one of the leaders for decades, and is a name synonymous with performance. We spoke with Jeff Teel, sales and client services expert at Hooker, and first asked him to explain the various coatings you can find on headers, and which ones might be a problem for header wraps.
“Industrial chrome or painted mild-steel headers will have the greatest potential for developing corrosion beneath the wrapping,” Jeff said. Most of us have owned a set of chrome or painted headers, While they look great going on, they don’t look so great a couple of years later. The heat cycles of the headers themselves, along with changes in outside temperatures, can wreak havoc on the finish. Jeff recommended the stainless steel, saying, “It is the most robust and durable material from which to build headers, in any case.”
While you might think ceramic coated headers would provide the best protection against corrosion, Jeff explained, “Ceramic-coated mild steel and even stainless-steel headers can also be affected by corrosion. However, it will happen to a lesser degree depending on the quality or application method used for the coating, or the specific type of stainless steel used to build the headers.”
We also asked about headers that have had the proper, high-temperature paint applied correctly, such as on clean steel. Jeff told us, “The degree of how well they will hold up depends greatly on environmental and usage factors.” When asked about ceramic-coated headers specifically, in addition to his thoughts on application methods, he said, “The primary tube-to-collector connection points is the area that is usually first to show signs of corrosion if the application is of higher quality.”
It seems no matter what you do, you’re going to see some form of corrosion either on the tubes themselves, or at the welded areas. So what’s the purpose of wrapping them up if it’s just going to cause problems anyway? For that answer, we reached out to Moroso National Sales and Marketing Manager, Thor Schroeder.
Header Wraps And Their Heat Control Properties
Header wraps are nothing new. Some people wrap their headers because they like the way it looks, others wrap their headers because of the tremendous reduction of underhood temperatures. Thor told us that header wraps can reduce the temperature by roughly 50-percent, and the surface temperatures can be reduced by as much as 30-percent.
What this equates to is a 300- to 400-degree drop in temperature, according to Mike Buca, DEI brand manager.
“We offer three basic material types: glass fiber, Titanium, and EXO,” said Mike. “Each has its benefits-to-cost ratio, with the glass fiber being the least expensive.” Those cost ratios increase not only in price, they also increase in heat protection. Mike continued, “Glass fiber is good for up to 1,200 degrees, while our Titanium wrap is good for up to 1,800 degrees. Our EXO wrap, which is designed for off-road use, is a glass fiber base, but it is inside a stainless-steel mesh sleeve.”
DEI’s Titanium wrap is more pliable than the glass fiber wraps, making it easier to install. But, Mike does warn us that you have to be careful and keep the wrap tight, especially with ceramic-coated headers. “Ceramic can be a little more difficult because of the slick surface,” he said. “But, this only comes into play when starting to wrap the pipes, once the wrap is installed, it’s fine.”
“Header wrap benefits can be broken down into two major groups,” Thor said. “The first is protection. Reducing engine compartment heat protects crew members from burns and prevents starter wires and plug wires from coming into contact with hot header pipes.” With that kind of surface reduction, it could be the difference between smelling something burning, to making it back home after a cruise.
“The second group is increased exhaust-cycle efficiency, ” Thor continued. “By retaining the heat in the header, it improves the scavenging of the cylinders by keeping the exhaust-speed high.” This very reason is why many companies offer a ceramic coating. The ceramic coating will help keep external surface temperatures lower than a painted or chrome header.
If you have ever done the burn test – where you reach in and accidentally burn your hand or your arm – then you know that a ceramic-coated header will cool down much quicker than chrome or painted tubes. The insulating properties of header wrap will help the scavenging process even more, because unlike ceramic, the material used in header wraps don’t retain heat on the surface.
Don’t Forget About Your Header Wrap
Once you’ve wrapped your headers however, you’re not done with them. There’s a bit of maintenance needed to ensure you haven’t had any abrasion that could cause the wrap to unravel or come loose. This abrasion could be from a steering linkage or other moving parts in the engine compartment. If this happens, the onset of corrosion can occur even quicker.
Should the header wrap start to unravel, Thor reminds us that a loose piece could get wrapped up in the engine’s pulley system. If that happens, you will get a rude awakening from the engine – and it won’t be pretty. That’s why you should always make sure they stay tightly wrapped. Even if it doesn’t start unraveling. “If it becomes extremely loose it will no longer be as effective as a thermal barrier,” stated Jeff.
Although Thor tells us that header wrap is designed to be installed and left on the headers, Jeff suggested it be inspected for corrosion, specifically on mild-steel headers. Inspecting headers periodically like we do with any other area of our engine is a good idea, up to and including unwrapping them to see the entire surface, and not just the weld joints on stepped headers or at the collector.
Another factor that can adversely affect the header wrap is engine fluids and oils. Thor said, “header wraps can last years, but they are affected by abrasion or being soaked in chemicals.” Those chemicals include typical oils and other fluids, as well as engine cleaners and degreasers.
Wrapping It Up
If you’re going to wrap your headers, both gentlemen suggest doing so with the headers removed, or wrapping prior to header installation. Thor said, “It’s always best to wrap them on a bench if that is an option. It allows the installer to get a nice clean wrap with proper coverage around the header or exhaust.”
Another reason wrapping the headers on the bench is best is because it allows you to see the back side of the header without using smoke and mirrors, or trying to cram your noggin down into the engine compartment to see. Additionally, it makes more sense when you think about having to lean over the fender and thread the roll between the primaries.
It seems both of our experts agree on the purpose and benefits of wrapping headers. While they both have a different hand in the matter, we can all agree that keeping the heat inside the header will help with performance, and keeping the outside temperature lower can protect other components in the engine compartment – especially an arm or a hand while reaching down to tighten or adjust something.
Of course, the decision to wrap or not to wrap ultimately relies on the user’s preference. Thor has some strong points as to why header wraps are significant, but neither he nor Jeff were in favor or against wrapping the headers. If you want to find out more about wrapping headers, reach out to Moroso Performance Products or DEI and let them know how you use your car and what type of header you have installed. If you’re planning on wrapping a new set of headers, check with Hooker Headers.