For example, plasma-sprayed bits of aluminum oxide can flake away from coated pistons (crowns) when used in a racing engine. This particular coating typically has a high Rockwell hardness level that can cause damage to other components (piston skirts, cylinder walls, and bearings) when small pieces of flaked coating are flushed into the oiling system, largely because of expansion and contraction rate differences between the coating and coated parts. Of course, this is not to say these types of coatings are not good for some applications because they can be. It's just additional reason that you should consult with your choice of coatings manufacturer or service provider to make proper materials and application selections.

Over time, as the coatings industry has become more mature and specialized, there does not appear to be one coating that fits all applications. The technology has become not only more sophisticated but also more application-specific. As an example of this, there are piston crown coatings presently available that address different mechanical compression ratios. So a central point is that what we're calling the "coating technology" has become much more specialized than in the past, driven by greater demands placed on racing components and ongoing advances in the design and performance of these parts and systems themselves.

From a practical standpoint, how does the weekly circle-tracker apply this information and technology? Two factors come immediately into play-cost and needs. Perhaps we should reverse these two considerations. What may be needed in a Cup engine or car (because not all coatings apply to the powertrain) might be too costly in a Late Model or Modified, for example. Overkill is neither necessary, nor desirable. The weekend racer wants parts to last, go a bit faster, and save costs where possible. As a rule, addressing possible overheating issues, galling of friction surfaces, concerns about achieving and maintain piston ring seal, and increasing functional durability of parts are all areas common to those of us in this category of racers, and there are cost-effective coatings available that are specific to those needs. These topics are generally areas where addressing solutions with various types of coatings does not involve expensive technology or processes. In fact, based on parts manufacturer experience, some components are supplied pre-coated.

With regard to racers who find themselves in this category, there are basically two market segments. Says Warren, "For the guy who feels he has insufficient technological skills, there are literally hundreds of applicators scattered around the country that apply these types of lesser-expensive coatings at a reasonable price, for which their customers will see gains in horsepower, extended parts life, reduced operating temperatures, potentially better braking, and improvement in cooling system efficiency. For example, if I was building an engine and was working from the lowest possible budget, I would coat the pistons, bearings, and exhaust system. This is where you'll see the greatest power gain for the level of investment made, particularly since parts failures are often tied to these three areas."

From the standpoint of how best to get parts coated, it seems there are three types of people involved. There will be those who always want to apply the coatings themselves. In which case there are materials available, although toxicity problems are to be avoided for the DIY group, and a retail supplier of coatings can advise about this.

Then there are those who will never want to conduct the applications themselves and, as previously mentioned, there are many applicators who can perform this service at a reasonable cost. And finally, based on the complexity or cost of the process, some people will base their decision on these considerations and decide whether to be in the DIY group or have someone do it for them.

As a suggestion, given the amount of information that can be found on the Internet, relative to coatings, further research that includes discussions with coating materials suppliers and coating service providers is not a bad idea. And in your research, keep in mind (depending on which parts are being coated) that it's possible the engine "tune" will require some adjustment. This is particularly true if you're working in the combustion space. Don't forget, we're dealing with a heat machine where combustion temperature and work performed on the crankshaft are integrated. Spark timing and fuel calibration changes may come into play.