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 valvesprings 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.
Types of Ceramic Coatings
· Thermal Barrier
· Anti-Friction
· Oil-Shedding
· Thermal Barrier Coatings for Exhaust Systems
· Anti-Corrosive and Salt-Shedding
Engine Components Ceramic Coating
· Crankshaft
· Camshaft Bearings
· Crankshaft
· Connecting Rod
· Connecting Rod with Main Bearings
· Wristpins
· Piston Top Coating
· Piston Skirt Coating
· Cylinder Heads
· Cylinder Head Ports
· Intake and Exhaust Valves
· Valvesprings
· Valve Retainers
· Lifters
· Lifter Bores
· Rocker Arms
· Pushrods
· Timing Gear
· Timing Chain
· Distributor Gear
· Intake Manifold
Exhaust Systems
· Exhaust Manifolds
· Headers
Brake Systems
· Calipers
· Brake Pad Backing Plate
Ceramic coatings of engine internal and external components will increase torque and horsepower by reducing friction, increasing lubrication, reducing part temperature, increasing combustion chamber efficiency, reducing detonation, oxidizing fuel more efficiently, shedding carbon, and keeping heat in the combustion chamber and exhaust system. It will also disperse heat from intake manifolds, cylinder heads, oil pans, brake components, wheels, alternators and carburetors; reduce thermal transfer into intake manifolds, cylinder heads, and brakes; reduce corrosion and chemical damage to parts; reduce fuel separation and dropout; increase port and exhaust velocity; and extend the part's life longevity. |
Performance coatings fall into four categories: Dry Film Lubricants, Thermal Barrier coatings, Thermal Dispersants, and Corrosion- and Chemical-Resistance coatings. |
Ceramic coatings are applied in a liquid form using an automotive detail spray gun. |
Part surface preparation is important, whether by means of media- or sandblasting, to remove any contaminants or porosity. Previously used parts may be pre-baked to sweat out any oil or solvent porosities from component pours. The ceramic liquid is lightly sprayed onto the part or component to avoid running. Most ceramics are water-based and very thin. |
All ceramics must be applied in professional spray booths, with certified ceramic filter systems. When applying ceramic coatings, it is better to use light multiple coats. |
Ceramic coatings are applied on headers to reduce underhood temperatures, reduce exhaust manifold and header surface temperatures, and increase exhaust gas velocity, which will help increase horsepower. Exhaust ceramic coatings are also available in different colors, including aluminum, cast-iron gray, dark blue, gold, white, and light blue/gray. |
After ceramic material has been sprayed, the component should be carefully inspected for even, uniform coverage for optimum performance results. Prior to being placed in the curing oven, the component is allowed to dry for five to 15 minutes at ambient temperature. |
After the components have dried, they are placed into the curing oven. The general temperature for most ceramic coatings to properly cure is 650 degrees Fahrenheit. The time may vary due to component size. |
After the component is removed from the curing oven, it is allowed to cool to room temperature. Then, it is placed in a vibratory polisher to obtain an optimum burnished or polished finish. The vibratory polisher is filled with Microbright ceramic beads and a polishing liquid. |
The component is submerged to guarantee a uniform polished finish. |
After a glossy polished finish is achieved, the component is removed from the vibratory polisher and dried. |
Here is the final result as compared to a non-ceramic-coated header. |
Exhaust system ceramic coatings come in different colors: polished, cast-iron, and polished aluminum. |
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