Spray -On Horsepower, Ceramic Coatings

Spray-On horsepowerCeramic Coatings
By Bob Ryder Who would have thought that horsepower could be gained from coating internal engine components? Internal engine components are made from dissimilar metals. Due to the lack of metallurgical similarities of these components, they absorb and dissipate heat at different cycling periods. The ability to protect and cool engine internal and external components actually contributes to noticeable horsepower and performance gains. The three major contributors to horsepower gain are heat resistance, friction reduction, and wear protection. Over the years, performance engine builders have been refining the leading edge of horsepower gains while experimenting with ceramic coatings. Ceramic coatings are used as a barrier between dissimilar metals to reduce friction, which cause heat, creating unwanted wear of internal engine components. By applying ceramic coatings to these dissimilar metal components, it will allow them to interface with one another more uniformly and compatibly. Prior to applying ceramic coatings to components, its surfaces must be prepped by media- or sandblasting. This will remove the component's outer crust surface and any contaminants, exposing the virgin metal underneath. Some feel that it is important to heat the component in an oven after it has been media- or sandblasted, to sweat out any additional contaminants or porosity from within its metallurgical molecular structure. If not, during the initial time the component is exposed to a heat cycle, some porosity may sweat to the surface and become trapped underneath the coated surface, causing the coated surface to de-laminate. It is very important for the component to be pure and clean before applying ceramic coatings. Ceramic coatings are available in a variety of coatings, including tungsten and titanium. The ceramic coatings are applied with an automotive detail touch-up gravity-fed spray gun with a nozzle size of about 0.8 inch, because its smaller size allows for better control. Most ceramic coatings are applied at 35 to 40 psi for solvent coatings and 50 to 60 psi for water-based coatings. It is best to apply ceramic coatings inside a spray paint booth using a respirator when using solvent- or water-based coatings. The ceramic viscosity, or thickness, is very thin and must be applied carefully, so it will not run. Most ceramic film application buildup is approximately 0.0003 to 0.001 inch. After the component is coated, it is inspected for uniform coverage, then allowed to air dry at room temperature to slowly begin the solvent- or water-based evaporation process, before placement in an oven to cure. It is best that the components are dried in an upright air-circulating oven to allow even heating for uniform curing of the component. The first increment of heat is 175 degrees Fahrenheit during ambient versus curing temperature transition for about 10 minutes, then cranked up to a cure temp of 600 degrees Fahrenheit for one hour. When building up a film barrier to 0.001 inch, this would affect clearances. After applying the ceramic film, the thickness is checked, then burnished with a ScotchBrite pad or similar material until the film thickness is no less than 0.0003 inch. This will allow the bearings to be run with its normal installed clearance. To polish Cermakrome coatings of exhaust manifolds and headers, it is best to use a vibrator type of polisher using Microbright ceramic balls and the appropriate polishing compound. The most common applications for ceramic coatings are on the exhaust system, manifolds, and headers. When ceramic thermal barrier coatings are applied to exhaust manifolds or headers, they provide two advantages. They protect the headers from rust and corrosion and also reduce heat loss, which translates into high power output. If the headers are internally coated, they will create a higher velocity of the hot exhaust gases and less turbulence due to a smoother surface. Pistons can also increase their performance characteristics with ceramic coatings. Coating the piston's crown and top will cause heat reflectivity, driving a percentage of any detonation energy back into the fuel burn zone, to increase fuel burn efficiency. It will also lower carbon buildup, which reduces detonation quality, as it builds up on the piston's crown and increases the risk of detonation damage to the piston crown surface. By protecting the crown and land diameter surfaces, it will allow for a leaner fuel mixture. Piston skirts can be coated to create an excellent dry sliding surface during engine start-up and will help eliminate skirt slap during initial engine run-in. Using a dry coating will fight against scuffing and abrasion of the piston skirt during its stroke travel inside the engine block cylinder. The inside of the piston can also be coated with an oil-shedding coating to cut parasitic drag and return oil to the sump faster. Ceramic coatings can also be applied over the piston ring contact face of OEM hard chromium, which provides lowering friction between the ring face and cylinder inner bore surface scuffing, and also improves wear resistance. Ceramic-coating the cylinder head's combustion chamber and exhaust ports will create a faster, hotter burn and help scavenge gases at a faster rate. The coating of these passages also creates thermal transfer from hot gases to the heads themselves. The cylinder head valley can be covered with an oil-shedding coating to speed the return to the sump. Some will coat the cylinder head's external surface with a thermal dispersant to aid in cooling the head. The valve-springs are coated with an oil-shedding ceramic to aid in the oil return to the sump. Camshaft bearing surfaces are not treated, but the rest of the camshaft is coated with a dry film lubricant. The crankshaft and connecting rods are sprayed with the oil-shedding coating to cut parasitic drag.An intake manifold is coated on the bottom with an oil-shedding coating to cut thermal heat transfer from the oil to the intake charge. It also helps eliminate fuel puddling on the intake manifold's internal floor surface. If the intake manifold floor is made too slick, it can hinder fuel and air atomization, not allowing the fuel and air mixture from tumbling, keeping the two suspended. The intake manifold's exterior can be ceramic-coated to reduce heat penetration, maintaining a cooler air/fuel mixture. Ceramic coatings have proven themselves in engine horsepower gain by reducing friction, heat, and wear.

More information can be found at http://www.engineceramics.com/