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"ceramic pistons"
#1
I'm not clear on what "ceramic pistons" means. I think it's a coating on the aluminum piston. Is it the top surface only or the skirt and top?

I don't see how a thin ceramic layer can affect the piston temperature at all -- the piston is going to achieve the average temperature of the environment regardless. I guess it could be a slight buffer for hot spots during the combustion phase for a millisecond or so, or maybe allows the top surface to heat super hot and burn off any carbon. If on the skirt, maybe it reduces friction.

What's the story?

Hoyt Stearns
Scottsdale, Arizona
http://HoytStearns.com
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#2
It is a thermal barrier coating to the piston deck. The ceramic has a lower heat transfer rate than aluminum so the aluminum part of the piston receives less heat from the chamber while still being cooled from the induction gasses below, therefore operating at a lower overall net temp. The much higher thermal capacity of the coating also spreads hot spots in the chamber out before contacting the aluminum below. The end result is that more heat stays in the chamber where it does work rather than in the piston where is does damage. There is also a skirt coating that reduces friction.
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#3
I had my pistons ceramic coated by H.M. Elliot Co. 387 Pit St. Mooresville, NC 28115 704 663-8226. The cost was about $60. I consider it cheap insurance. Elliot is reputable and does a lot of work for the local NASCAR shops. one thing more...If you elect to do the coating, it reaches full cure in the cylinder at operational temps. Resist the urge to test it by scratching it before install. Also, the cylinders need to be removed one at a time and re installed. Best Regards, Paul
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#4
John is right about why you want to coat the pistons. Less heat absorbed into the engine means more work done in the form of horsepower. This is a good site to read up on coatings. http://www.techlinecoatings.com/artic... If you really wanted to do everything you would ceramic coat the head and exhaust ports and coat the piston skirts with their low friction coatings. If you don't think this is important think about what happened to the space shuttle when the ceramic tiles failed.
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#5
Thanks for the link. It looks as if I can do my own coating with part #2213 and perhaps #3401. Is there a reason that's not recommended?

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#6
I plan on doing my head and exhaust port myself so I don't see why not. I guess it depends on how cooperative your wife is for the oven.
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#7
Dkeith - 1/26/2008 4:11 PM

I plan on doing my head and exhaust port myself so I don't see why not. I guess it depends on how cooperative your wife is for the oven.

I would personally ask some serious questions before I cured something in the oven I used to cook with. There could be some serious consequences with the material used.

Just my opinion,

James L
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#8
My wife just does not cook anymore, kids grown and gone. We eat out alot. You have given me an idea though, great place to hide stuff. Smile Coating the heads and exhaust ports is a good idea, I'll look into it.
Skeeter
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#9
You guys have me wondering something now.

If the engine is not absorbing as much heat.....are we using the correct EGT temps.

Before you jump to some conclusion......let me explain my thoughts.

If the engine is absorbing less heat, more of the heat must be going out the exhaust pipe. If this is true, the temps shown on the EGT gauge are hotter than normal. At that point, we would richen up the engine to keep the temp within the "normal" range. We would really be burning more fuel, and be less efficient.

Has anyone replace their pistons on a previously run engine, and witnessed a rise in EGT? (albeit, it was probably not a huge rise)

Just wondering,

James L
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#10
I guess this gets back to the fuel injection issue and using a wide band oxygen sensor in the exhaust to set mixture and not temperature.
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