Spray-on ceramic coating dramatically reduces external temperatures
By Mike Hanlon
December 18, 2006
December 19, 2006 A high-technology ceramic coating originally developed for the nuclear industry and already used by five Formula One teams is now available for automotive applications. Applied to the exhaust manifold using a high-temperature plasma spray, the Zircotec coating greatly reduces the release of heat, helping to protect the finish of the manifold, the engine and other components in the engine bay. The coating can also be applied to turbo housings, cam covers, heat shields and other metal components. Testing by race teams has shown a reduction in under-bonnet temperature of up to 25ºC and power improvements, from the lower air induction temperatures, of up to six percent. One motorcycle racing team that employed the system used a laser-guided thermometer and found that while the exhaust can have an internal temperature of around 150 degrees Centigrade, the outside temperate can be low enough for the exhaust pipe to be removed WITHOUT using gloves.
The beauty of the plasma-sprayed ceramic coating treatment, apart from the fact it solves a lot of heat soak problems for car and bike builders, is its affordability.
Lower temperatures also increase the durability and effectiveness of engine and transmission oils, improve engine cooling and help to protect ancillaries such as starters, regulators, wiring and modern alarm and ignition systems from the degrading affects of excessive heat. Hot starting can also be improved through reduced fuel vapourisation.
“Heat can be very damaging in any car, but classics are particularly vulnerable,” explains Zircotec technical director Andy McCabe. “Period-style materials and finishes often just cannot cope. Start upgrading the engine and driving the vehicle hard and it becomes even more of an issue. Our technology will help provide modern comfort, reliability and durability, plus a long-lasting period look, for any classic vehicle.”
Unlike ceramic paints and coatings applied by other techniques that can burn off and become brittle, leading to flaking, the Zircotec process is proven to be highly durable in even the harshest motorsport applications. It can also resist local impacts like minor knocks during maintenance and is neater, more compact and more durable than old-style ceramic wraps.
The technique is being used by Desmond J. Smail, one of Europe’s leading specialists in exceptional classic Aston Martins. “Most classic cars have very poor thermal management from new,” explains Desmond Smail. “Our customers today don’t want to be cooked by exhaust manifolds close to the scuttle or have the finish of their rebuilt engine ruined by heat within a few thousand miles. They also expect reliability equivalent to modern vehicles, so components and fuel systems have to be protected from the heat of the engine. The Zircotec coating has proved extremely affective at addressing all of these issues.”
Smail also points out that the plasma-sprayed ceramic coating is often chosen just for its aesthetic qualities. “In its white natural state it looks like period asbestos paint, but of course it lasts many times longer making it ideal for competition cars. For road cars, we usually specify a silver finish that matches the engineering quality of the DB series,” he says. “We have found Zircotec to be a very professional business, managed by people who genuinely care about quality and service. They are a great supplier for a specialist in high-quality, high-performance restorations.”
The Zircotec process
Zircotec’s zirconia-based ceramics have a thermal efficiency of less than 1.7 W/m K, so provide an excellent thermal barrier. When applied to an exhaust system, the Zircotec coating inhibits the radiation of heat from the surface of the material, holding the heat inside. The coating can also be applied to other metal components including heat shields. For modern vehicles, the latest development is a coating for carbon fibre panels.
Systems for coating can be sent to Zircotec’s technical centre at Harwell, where they will be coated and dispatched within five working days. A premium two day service is also offered. Call 01235 434326 to discuss specific applications