What if...

[country63sedan]

What if a person were to jet coat combustion chambers? Since a large percentage of fuel's energy is wasted to the cooling system, why not cut this loss before it happens? I assume this would open up lots of options for compression ratios, cam profile, cam timing, and ignition timing. I realize adhesion to the head casting would be tough under the temp and pressure it would face, but if it stuck, then what? Would an aluminum piston hold up tothe added heat? Maybe I'm crazy, but this seems reasonable. Maybe I should just lay off the dr. pepper.    Later, Travis

[jayb]

You mean like a ceramic, heat reflective coating, right?  That's actually fairly common practice in some race engines.  I did it on my supercharged 490" FE.  I had the combustion chambers, valves, and intake and exhaust ports coated at this place called Swain coatings in Michigan.  Barry at Survival Motorsports got it done for me, because I bought the Blue Thunder heads from him.  I also had the pistons coated at Diamond Pistons when they were made for the engine.

The theory is that the less heat escapes into the castings and cooling system, the more heat is available to make pressure in the cylinder, and thus an engine with coatings will deliver more horsepower than one without.

In addition to Swain, there is an outfit in Texas I think, called Polydyn coatings, that also does this work.  Blair Patrick uses them, and I've gotten pistons from him before that have this coating on them.  I kind of liked it better than the Swain coatings.

Applications of the coatings is critical, and if you don't do it right, they will flake off and become useless.  I tried to do it myself once with some products from a place called Techline coatings, but despite my best efforts, a teardown on the engine after the dyno sessions showed that the coatings on the pistons were starting to flake off.  On the other hand, I've torn down engines where the pistons have been professionally coated, and everything on the piston tops has looked intact.  So if done correctly, there is no doubt that the coatings will live. 

Hope that helps - Jay

[Pentroof]

Barry is in Michigan, but Swain isn't. Dan Swain has a degree in Ceramic Engineering (as I do) and has been in the industrial and performance coatings business for many, many years (I prefer to play with jet engines). Deep roots with Nascar teams and many of the leading drag teams with results to back it up.

This is not the crap you find on headers, this is the real deal. I'm not as familiar with the other shop that Jay mentioned, so I can't comment.

[country63sedan]

Thanks guys, I didn't figure I had an earth shattering new idea. It is good to know I had a sound theory though. Since I'm dealing with folks who have done this - what is the gain vs cost? Is it one of those million dollars for that last 5 horses kind of thing? Am I right about more options for cam, compression and ignition? Thanks, Travis

[jayb]

Thanks to Pentroof for the correction on Swain's location; I had assumed they were local to Barry.  As far as cost/benefit, I'm not sure if there's any data available; I certainly don't have any.  It would make an interesting dyno test, though.  But my guess is that it would be relatively expensive from a horsepower per dollar perspective.  On a blown engine, it may be more about making the parts survive under adverse conditions, such as inadvertently running lean.  That's why I did it on my engine; I didn't want a carb hiccup that made the engine go lean to start burning components.

[cammerfe]

When Roush's engine shop for NASCAR engines was in Livonia, one small corner of the storage mezzanine was taken up with a set-up to coat pistons. The coating was applied by a guy using an airbrush. After allowing the pistons to dry, they were baked in an oven. This wasn't a 'let's try it' sort of operation---his engines had this technology incorporated.

My latest set of Ross pistons for a turbo application came to me coated also. But where the coating Roush's people were applying was a dark grey, the Ross material is almost a gold color.

KS

[country63sedan]

Sounds like it's out of my budget/unnecessary right now. Some day when I'm rich I'd like to mess with twin turbos in the wagon though. Later, Travis

[Pentroof]

Much of my professional life has been dedicated to this subject, so I like to talk about it.

The most important thing to keep in mind is how the coating works and what is needed to support it. All that is really going on is a reduction in the rate of thermal conduction to the parent material. After time, the material will still get to full temperature if it is not actively cooled from the backside.

So, for a piston, it will eventually still saturate at the same temperature if the engine is run long enough. That said, running the engine for any duration beyond the short term benefit of the coating without any other changes is a net of no change (well, except for aded weight and cost). So, in a drag race application, there is benefit for pistons because the motor is not run very long. However, after several runs and heat soaking, this is minimized.

Application on the combustion chamber is a different story because of the constant cooling taking place on the internals of the casting by the cooling system. The result here is less heat loss to the head and more heat retained for combustion. This should also be taken into consideration when designing the system.

The really good builders that are employing TBCs have many other design changes to support the use of the coating. For example, if you look inside one of those engines, you will see active cooling on the backside of the pistons with a series of jet nozzles spraying oil. Additional cooling may be required for the coolant as well as the oil.

TBCs are for the builder who is looking for that last few horsepower. The order of magnitude would be similar to what you would see by leaning the motor out and then taking advantage of that heat.

In my industry, turbine blades are able to live in gas stream environments above the melting point of their Nickel alloys. This is only possible because of the TBC and the active internal air cooling.

OK, back to the garage...

[country63sedan]

I hadn't thought of the heat soak issue, but then I hadn't thought of coating any components besides the combustion chambers. My original reason for the post was to answer some questions about fuel mileage. I believe a lot of fuel efficiency is wasted to the cooling system.                                                                                                                                        I have an idea to build a 390 (maybe bigger) for moderate hp, but lots of torque at low rpm. I'm thinking about 3.00 gears with an overdrive 5 speed, and putting this in a big heavy wagon. I believe that a big engine spinning slow should get comparable mileage to a small engine spinning fast.
     I'm a little concerned about detonation from so much load at a low rpm, and I think a smooth coating would also help with that. Mainly I'm just thinking about getting the most bang from a gallon of gas, I drive around 90 miles a day and when the wagon is done I would like to drive it a lot. The only time I've seen a 63 Ford wagon on the interstate, it was on a trailer behind me 
    If anyone has suggestions or ideas, I'm all ears.  Thanks, Travis.


  Forgot to mention - I plan to adapt an EEC IV system to this using a streetmaster intake. Sorry this is so wordy.

[Barry_R]

Absolutely correct.  Dan Swain became something of a friend a while after I had contracted him to do the bearing coatings for Federal-Mogul.  Started out stating that nobody could duplicate his material and technique. 

He was kinda stunned when I was able to provide him with full analysis of his proprietary coating sample, both in terms of deposition thickness, adhesion quality and chemical makeup.  After letting him catch his breath I explained that F-M had a SEM on site and that another personal friend of mine was involved in NASA and aerospace coating evaluation.  Between the two I was able to get a decent grasp on things - even with my very limited knowledge.  And that I had absolutely zero interest in duplicating his efforts even if I could (I can't even come within a country mile).

He always delivered exactly what was asked of him, on time, and on target for both quality and cost.  And he is one heck of a nice guy too.  He is not directly involved in the day to day aspects of the business these days, although I saw him a PRI a year or two ago.

[rcodecj]

I took it to have it clear coated and they thermal barrier coated the inside and outside by accident. When I showed up to pick up my intake, they said, "How do you like your intake". I looked over at this brown intake that looked like $hit, and said that better not be my intake. It was. They blasted the outside off and clear coated it, but left the bottom and inside coated. So I guess I got it done for free. I have an infrared thermometer, I guess I should see how cool it stays. I remember at the time the shop was coating pistons and combustion chambers too. Here's a few pics: