It's fair to say that although certain engine and powertrain components (pistons, bearings, and headers) are frequent targets for knowing and learning about coatings, there are multiple other areas where friction or heat management can benefit from existing materials and processes. Of course, that isn't meant to imply new coatings won't continue to be introduced because they will be.

Just keep in mind that hard parts technology is also a moving and evolving target. Hard parts design refinements that include improved materials may not respond to coatings the way earlier versions of the same parts may have responded.

For example, as valvespring technology continues to advance, coatings applied to former spring material may not be required today-or at least require the same coating compound as before. And while the developers and manufacturers of coatings are aware of this changing landscape, it further underscores the importance of communicating with your choice of retail source or service provider, just to make certain of getting the most up-to-date information pertaining to your specific requirements.

Primary Categories Of Coatings

Thermal Barriers
These are just as the term implies-insulators or coatings that aid in the retention of heat in a way that improves engine performance or parts life. For example, such areas as piston crowns, combustion chambers, intake or exhaust valve faces or exhaust system components can benefit from the use of coatings that have thermal retention or insulating properties. It's important to understand and remember that we're dealing with a heat machine where power equates with heat, in a controlled environment. In other words, if the heat of combustion that should be released as "work" done on the rotating and reciprocating parts of an engine becomes liberated to other areas counterproductive to this objective (cooling system, combustion surfaces, atmosphere, and so on), net power will be reduced. However, as pointed out in the core story, it's not a bad idea to consult with your choice of coating materials manufacturer or supplier to determine not only the full ranges of coatings and/or coatings services available before making a decision about which thermal barrier material (or any other type coating for that matter) might be best for your particular application. But by definition, thermal barrier materials are intended to retain heat.

Thermal Dispersants
Again, the name is linked directly to the function. Thermal dispersants are intended to help remove heat from areas where a particular part or system benefits from a reduction in temperature build-up. These coatings are of value where either ongoing heat concentration or even temperature spikes are present and unwanted. Brake system components and oil pans are frequent targets for thermal dispersants. And here's something to not overlook. Sometimes, an effective thermal dispersant will allow you to re-think how a particular part or system is designed. For example, by rapid dispersion of excessive cooling system heat, a properly coated radiator may allow you to reduce the part's overall size, thereby providing an opportunity to reduce the car's frontal area and, accordingly, decrease net aerodynamic drag. In a sense, that's equivalent to an increase in power available to propel the race car. Benefits from sensible use of coatings is not always confined to heat or friction control.

Dry Film Lubricants
Relative to engine performance, a reduction in friction horsepower nets a gain in power at the flywheel. Mathematically speaking, friction horsepower is the numerical difference between ihp (indicated horsepower) and bhp (brake horsepower). In other words, brake horsepower increases as friction horsepower decreases. Dry film lubricants, in terms of horsepower, tend to reduce friction horsepower, in addition (in many instances) decreasing the operating and work-surface temperature of parts coated with DFLs. Examples of parts that can benefit from this type of coating include valvesprings, piston skirts and pins, bearings (rod, main, and camshaft), and oil pump gears. In many cases, manufacturers of these types of parts offer them pre-coated or will perform that service for you, if requested. But as previously suggested, it's generally a good idea to consult with your choice of either the suppliers of coatings materials or parts manufacturers to get their views on which coatings may be best for your particular application and needs, or both.

Calico Coatings
6400 Denver Industrial Park Rd. P.O. Box 901
NC  28037
Tech Line Coatings, Inc.