I have been reading alot of articles on the subject of thermal coating thought I would write a little bit on the subject for those looking for extra HP with there rebuilds. Thermal and friction reducing applications are applied after the part is etched. The part is cleaned, the coating is applied and then oven cured. This insures that the application, unlike paint, is tougher and more than skin deep. Before I say any more, what are thermal coatings, and what do they do? Thermal coatings come in two basic categories; thermal dispersants to help get rid of heat and thermal barriers to block heat. Thermal dispersants help the coated part shed heat faster than that part normally would dispense with were it bare or un-coated. Thermal dispersants are generally exterior coatings and therefore primarily work via convection, but conduction is also involved.
The semi-gloss black external coating is a Thermal Dispersant, it gets rid of heat faster and more efficiently than bare metal, it also sheds mud and rubber. Typical applications are cylinders, cylinder heads, intake manifolds, brake calipers, radiators and oil coolers. Always properly warm up your engine before operational loading. It will now take longer for your engine to come to operating temperature. Clean with soap, water and/or light solvents, do not leave it to soak in a solvent tank.
Other types of coatings include Thermal Barriers and Dry Film Lubricants. Thermal barriers as the name implies are barriers or shields to thermal events or heat. An internal combustion engine is basically a thermally controlled air pump. So various engine events will depend on heat to function properly while others depend on the elimination of heat to live. Remember, an engine's working fluid is air, introduce an air charge into the combustion chamber, provide an ignition source with a combustible compound to heat it at the correct time, and you produce work. Sounds easy, however heat is the key to making a little power, a lot of power, or seizing the engine.
Heat as it relates to a high performance racing engine is different conceptually from what is wanted by a smog controlled street engine. While the conceptual differences are there, as are the reasons for each argument, the results are similar. Combustion efficiency produces more work with less fuel and less residual emissions. Areas to hold heat into include, the combustion chamber and exhaust systems and areas to shed heat include most everything else. On the intake side, the cooler the intake air the more dense the air charge. However, there are instances, EPA, CARB environmental controls, evaporation levels of certain fuels, that demand higher but moderated temperatures. Controlling the heat of the combustion process and the exhaust elimination system can assist in maintaining control over both engine interior and exterior temperatures. An engine certainly does get hot under the hood. Studies have documented temperature drops of 100 to 300 degrees of under hood heat. What do you think dropping under hood temperature 100 degrees does to your inlet charge temperatures? Barrier coatings on exhaust system components contain the heat into the system and preclude the heat from just migrating around the semi-closed container called your engine bay.
I am sure you have all heard the term ceramics applied to automotive-coated parts. While ceramics are used in automotive applications, their use is still relatively new and cutting edge. Ferrari and other Formula One teams are currently using ceramics in both engine and suspension applications. But for the average guy or gal on the street, their use is minimal outside of thermal barriers. Barrier coatings do contain amounts of ceramic but they are not pure ceramic for one very important reason, coefficient of expansion. Aluminum alloy for example, will expand at 13.7x 10(-6th) while zirconia based ceramics expand at 4.16x 10(-6th) in the temperature realms of 80 to 800 degrees Fahrenheit. Aluminum obviously expands at a far greater rate than does the ceramic, which makes it hard to keep them in contact with each other for very long. While steel headers for example, will expand less than aluminum, steel is still affected by heat more than and therefore its expansion rate is greater than the ceramic too. Coating pistons, valves, combustion chambers, turbocharger exhaust manifolds and turbine housings, exhaust ports, and exhaust headers and pipes is where thermal barrier coatings most useful work is done. Keeping the combustion heat into the combustion chamber where it belongs and not allowing it to migrate throughout the engine is important. As exhaust gas speed and wave intensity is directly related to temperature elevation and the consistency of the temperature throughout the length of the pipe. Maintaining elevated and constant temperature throughout the length of the system is paramount to effective scavenging and evacuation. Thermal barriers hold that heat into the system helping it to perform better and also protecting the coated parts from rust corrosion and premature damage.
So where does all of that internally combusted heat go to? It goes to the same places it normally does but now we are trying to control and positively use the normally wasted heat energy. Normally, part will go into the cooling system to be eliminated via the radiator or in the case of air-cooled engines, cooling fins. Part will go out the exhaust system as additional waste. The remaining thirty percent or less is actually used to produce work and turn the crankshaft. It should not take a rocket scientist to realize that increasing the latter's percentage even in small amounts will garner additional returns in work and power.
I have found that coated pistons will protect against the damaging effects of uncontrolled excessive combustion chamber heat, detonation and/or pre-ignition. This could ordinarily lead to a hole in the piston in two strokes and/or ring land damage in a four-stroke engine. Thermal barrier coated pistons transfer less heat to wrist pins, cage bearings and the general crankcase area. Thermal barrier coated intake and exhaust valves will not transfer their normal amount of heat directly to the valve springs, hence the springs last far longer than normal. As the valves themselves do not get as hot, they do not wear the respective valve seat contact areas as quickly, parts last longer with less heat. Thermal barriers will not totally prevent engine damage caused by tuning errors that lead to severe detonation and or pre-ignition. They will not improve your sex life, eliminate problems caused by general ignorance and/or help from your friends who know everything or create world peace. However, they will protect vital internal engine components far longer and provide an extended range of extra protection when things do go wrong. By coating these parts, we hold the heat in to where it belongs, the combustion chamber. We gain usage of more of the potential and available BTU's (British Thermal Units a system of measuring heat potential) to use in order to convert our inlet charge to work. Heating the air to turn the crankshaft translates into the potential for more work and power.
Dry Film Lubricants and friction reducers are lubricants that maintain themselves in a dry state. Friction is a force that resists motion between two bodies or parts in contact with one another. Lubrication is necessary to reduce friction and prevent metal to metal contact within your engine's various moving parts. A thin film of oil, sometimes only ". 000025 of an inch" thick is all that holds your engine parts apart and moving. Dry films work and provide protection at all times, however, they provide special lubricity and extra protection when combined with liquid lubricants. You might think of dry film lubricants, as you would think of freeze dried foods, you add liquid to make them work even better. Dry films are a mix of various very slick materials, in a resin-bonded matrix. The application process is similar to thermal coatings and the lubricants are imbedded into the metal. Dry film lubricants are designed to reduce friction, which produces heat. They also reduce metal to metal interaction and wear. Reducing friction in piston skirts, valve springs and bearings extends their life and lowers the engines overall friction coefficient. This again translates into more power at the crankshaft instead of negative parasitic power losses. Dry films also assist during break-in periods, less wear means less metal residue in the oil pan, etc., etc., etc. As dry film and friction reducing lubricants are bonded into the metal, under extreme conditions and duress, they remain in and on the parts long after grease or oils have burned away.
Depending on engine modifications, your location, air pressure and quality, etc., you may need to re-adjust or re-jet your engines fuel and ignition systems. Do this carefully, i.e. richer and retarded is better to start with. Always error on the side of caution, it is much less costly.
The primary goal is improving airflow and volumetric efficiency primarily via porting of the engines air passageways. However, improved volumetric efficacy by improving the quality of the air or fluid charge by lowering the temperature of that charge to gain more oxygen per volume. Air is the working fluid of internal combustion engines, so air is the fluid I am referring to here. When we lower the temperature of our working fluid/air, it becomes denser. One of the ways in which we lower the temperature of the inlet charge and engine and achieve this volumetric advantage is through the world of THERMAL COATINGS.
I hope this sheads a little light on this subject. I have done a lot of motor building for hondas and have seen longer lasting engines. Turbo engines have even more to gain from heat control. I am currently in the prosess of building a fully coated 6 bolt, and I will compare under hood, and IAT, readings before and after the thermal coatings.
Dan
The semi-gloss black external coating is a Thermal Dispersant, it gets rid of heat faster and more efficiently than bare metal, it also sheds mud and rubber. Typical applications are cylinders, cylinder heads, intake manifolds, brake calipers, radiators and oil coolers. Always properly warm up your engine before operational loading. It will now take longer for your engine to come to operating temperature. Clean with soap, water and/or light solvents, do not leave it to soak in a solvent tank.
Other types of coatings include Thermal Barriers and Dry Film Lubricants. Thermal barriers as the name implies are barriers or shields to thermal events or heat. An internal combustion engine is basically a thermally controlled air pump. So various engine events will depend on heat to function properly while others depend on the elimination of heat to live. Remember, an engine's working fluid is air, introduce an air charge into the combustion chamber, provide an ignition source with a combustible compound to heat it at the correct time, and you produce work. Sounds easy, however heat is the key to making a little power, a lot of power, or seizing the engine.
Heat as it relates to a high performance racing engine is different conceptually from what is wanted by a smog controlled street engine. While the conceptual differences are there, as are the reasons for each argument, the results are similar. Combustion efficiency produces more work with less fuel and less residual emissions. Areas to hold heat into include, the combustion chamber and exhaust systems and areas to shed heat include most everything else. On the intake side, the cooler the intake air the more dense the air charge. However, there are instances, EPA, CARB environmental controls, evaporation levels of certain fuels, that demand higher but moderated temperatures. Controlling the heat of the combustion process and the exhaust elimination system can assist in maintaining control over both engine interior and exterior temperatures. An engine certainly does get hot under the hood. Studies have documented temperature drops of 100 to 300 degrees of under hood heat. What do you think dropping under hood temperature 100 degrees does to your inlet charge temperatures? Barrier coatings on exhaust system components contain the heat into the system and preclude the heat from just migrating around the semi-closed container called your engine bay.
I am sure you have all heard the term ceramics applied to automotive-coated parts. While ceramics are used in automotive applications, their use is still relatively new and cutting edge. Ferrari and other Formula One teams are currently using ceramics in both engine and suspension applications. But for the average guy or gal on the street, their use is minimal outside of thermal barriers. Barrier coatings do contain amounts of ceramic but they are not pure ceramic for one very important reason, coefficient of expansion. Aluminum alloy for example, will expand at 13.7x 10(-6th) while zirconia based ceramics expand at 4.16x 10(-6th) in the temperature realms of 80 to 800 degrees Fahrenheit. Aluminum obviously expands at a far greater rate than does the ceramic, which makes it hard to keep them in contact with each other for very long. While steel headers for example, will expand less than aluminum, steel is still affected by heat more than and therefore its expansion rate is greater than the ceramic too. Coating pistons, valves, combustion chambers, turbocharger exhaust manifolds and turbine housings, exhaust ports, and exhaust headers and pipes is where thermal barrier coatings most useful work is done. Keeping the combustion heat into the combustion chamber where it belongs and not allowing it to migrate throughout the engine is important. As exhaust gas speed and wave intensity is directly related to temperature elevation and the consistency of the temperature throughout the length of the pipe. Maintaining elevated and constant temperature throughout the length of the system is paramount to effective scavenging and evacuation. Thermal barriers hold that heat into the system helping it to perform better and also protecting the coated parts from rust corrosion and premature damage.
So where does all of that internally combusted heat go to? It goes to the same places it normally does but now we are trying to control and positively use the normally wasted heat energy. Normally, part will go into the cooling system to be eliminated via the radiator or in the case of air-cooled engines, cooling fins. Part will go out the exhaust system as additional waste. The remaining thirty percent or less is actually used to produce work and turn the crankshaft. It should not take a rocket scientist to realize that increasing the latter's percentage even in small amounts will garner additional returns in work and power.
I have found that coated pistons will protect against the damaging effects of uncontrolled excessive combustion chamber heat, detonation and/or pre-ignition. This could ordinarily lead to a hole in the piston in two strokes and/or ring land damage in a four-stroke engine. Thermal barrier coated pistons transfer less heat to wrist pins, cage bearings and the general crankcase area. Thermal barrier coated intake and exhaust valves will not transfer their normal amount of heat directly to the valve springs, hence the springs last far longer than normal. As the valves themselves do not get as hot, they do not wear the respective valve seat contact areas as quickly, parts last longer with less heat. Thermal barriers will not totally prevent engine damage caused by tuning errors that lead to severe detonation and or pre-ignition. They will not improve your sex life, eliminate problems caused by general ignorance and/or help from your friends who know everything or create world peace. However, they will protect vital internal engine components far longer and provide an extended range of extra protection when things do go wrong. By coating these parts, we hold the heat in to where it belongs, the combustion chamber. We gain usage of more of the potential and available BTU's (British Thermal Units a system of measuring heat potential) to use in order to convert our inlet charge to work. Heating the air to turn the crankshaft translates into the potential for more work and power.
Dry Film Lubricants and friction reducers are lubricants that maintain themselves in a dry state. Friction is a force that resists motion between two bodies or parts in contact with one another. Lubrication is necessary to reduce friction and prevent metal to metal contact within your engine's various moving parts. A thin film of oil, sometimes only ". 000025 of an inch" thick is all that holds your engine parts apart and moving. Dry films work and provide protection at all times, however, they provide special lubricity and extra protection when combined with liquid lubricants. You might think of dry film lubricants, as you would think of freeze dried foods, you add liquid to make them work even better. Dry films are a mix of various very slick materials, in a resin-bonded matrix. The application process is similar to thermal coatings and the lubricants are imbedded into the metal. Dry film lubricants are designed to reduce friction, which produces heat. They also reduce metal to metal interaction and wear. Reducing friction in piston skirts, valve springs and bearings extends their life and lowers the engines overall friction coefficient. This again translates into more power at the crankshaft instead of negative parasitic power losses. Dry films also assist during break-in periods, less wear means less metal residue in the oil pan, etc., etc., etc. As dry film and friction reducing lubricants are bonded into the metal, under extreme conditions and duress, they remain in and on the parts long after grease or oils have burned away.
Depending on engine modifications, your location, air pressure and quality, etc., you may need to re-adjust or re-jet your engines fuel and ignition systems. Do this carefully, i.e. richer and retarded is better to start with. Always error on the side of caution, it is much less costly.
The primary goal is improving airflow and volumetric efficiency primarily via porting of the engines air passageways. However, improved volumetric efficacy by improving the quality of the air or fluid charge by lowering the temperature of that charge to gain more oxygen per volume. Air is the working fluid of internal combustion engines, so air is the fluid I am referring to here. When we lower the temperature of our working fluid/air, it becomes denser. One of the ways in which we lower the temperature of the inlet charge and engine and achieve this volumetric advantage is through the world of THERMAL COATINGS.
I hope this sheads a little light on this subject. I have done a lot of motor building for hondas and have seen longer lasting engines. Turbo engines have even more to gain from heat control. I am currently in the prosess of building a fully coated 6 bolt, and I will compare under hood, and IAT, readings before and after the thermal coatings.
Dan
