Ceramic Coating Pistons

[Waystro]

What's the benefit of ceramic coating Piston/Slugs/Graboids what ever you want to call them.
Thinking since I'll have them out might as well.

 

[IDIoit]

ceramic has great thermo conductivity.
i deal with ceramics everyday, they are perfect for high heat applications.
(my products often leave this planet)

these are not a budget item tho, ceramics do add material to the piston, so in theory, the slugs need to be shaved to compensate for the added material.

you do not want to find the cheapest place to ceramic coat your pistons.
a sub par application will result in adhesion failure.

once you get ceramics into your oil galleys, your engine is pretty much done for.

the bottom line is, if youre not doing a crazy high HP, high heat build, it is money wasted.

 

[Waystro]

Hmm not planning on crazy HP don't really want to do any shaving or boring.

 

[HS108]

What about coating my exhaust elbow for my idi? I was real big into RX7s before I got into diesels and jeeps, and the big craze when I lieft was coating the exhaust tubes and the elbow on them and this was back in 04 05

 

[icanfixall]

Ceramic top pistons makes the heat brush off the top of the piston if thats the terminology you need to see. Mahle who was the oem maker for every idi engine makes a piston that has a reflective coating on them too. Its a black coating and it works fine. If you choose to ceramic the piston tops they MUST be snad blasted and coated immediately or the coating will not stick. In my information at the bottom of my posts tells you who and what I used. Believe me it was hell sand blasting off the Mahle piston coatings too. You and I can not apply the coating I purchased. They only sell to a shop they know and recommend to do this work. This is one place going cheap will not be a good thing.

 

[BDCarrillo]

There are other "snake oil" coatings for piston skirts... The jury is still out on most of them. If it's applied with an airbrush rig, it's probably just some colored "feel good" garbage...

 

[Waystro]

What about coating my exhaust elbow for my idi? I was real big into RX7s before I got into diesels and jeeps, and the big craze when I lieft was coating the exhaust tubes and the elbow on them and this was back in 04 05

Don't see why not. I'm still planning on ceramic coating the headers. Might paint with a high temp. Still have to do some searching on that tho.

 

[BDCarrillo]

Ceramic coating NA headers is a luxury to slightly drop underhood temps and makes a tiny difference in exhaust velocity over the length of a whole exhaust system.

Ceramic coating turbo headers/up pipes helps to retain heat pre-turbo. Hotter, more energetic gasses spinning your exducer blades=mo' betta power. How much? It's hard to say exactly... you'd have to find dyno charts. Ceramic coating parts downstream of the turbo would be pretty wasteful, unless you had radiant heat issues with other items near the plumbing.

 

[jaluhn83]

The ceramic coating acts as a heat barrier - same idea as having a glove on when you get something out of the oven. When used on a piston crown this significantly reduces the amount of heat transferred into the piston from the combustion gasses which results in the piston being cooler and less heat transfer to the cylinder walls/oil system (piston is cooled to a large degree by oil spraying on the underside) Since piston temperature is a limiting factor, this has obvious benefits. It will also result in the combustion gas retaining more heat which could improve efficiency slightly and make the turbo work better though I think the practical benefit is questionable. Mainly it helps protect the piston from temps and reduces the rejected heat.

I got mine down at the last rebuild and have had good luck so far. I had a crown coating and a skirt coating done - skirt coating is supposed to be a moly coating that will help prevent scuffing/seizing by adding a solid lubricant to the piston/cylinder interface if it ever starts rubbing (ie from overheated piston) Not sure how well it would work in practice but IIRC it was either a package deal or a very cheap add on, so worth the peace of mind.

Coating the exhaust pipes could help retain heat between engine and turbo and help reduce radiant heat from the pipes - the later being helpful to keep underhood temps down and for places where the pipes are close to the body, ie downpipe.

I would recommend it for an engine built for a moderate to high pressure turbo - basically anything over the standard 10psi system. Not that expensive and worth it IMHO.

The coating adds about 0.005" IIRC - it's think enough to not be a significant issue with a stock piston, though if you're into it that far you may as well deck them 0.010-0.020" first to help with a higher boost.

 

[CCPcoatings]

What's the benefit of ceramic coating Piston/Slugs/Graboids what ever you want to call them.
Thinking since I'll have them out might as well.

In the context of "Motorsports / Performance" applications, ceramic coating is used to protect the piston from excessive heat. "Excessive Heat" can result from increased boost via turbo / supercharger, NOS, lean tunes, detonation, etc, etc.

Contrary to "IDIoit's" feedback, "Ceramic's" are utilized because they are NOT a good thermo cunductor. i.e., ceramic coating on the piston dome REJECTS heat from soaking into the piston or mutant flames / spark burning into the piston. Whereas an example of a GOOD thermo conductor would be a heat sink on your CPU or the copper or aluminum radiator in your car / truck. In the coating world, a Heat Dissipating coating would be a GOOD thermo conductor because it transfers / dissipates heat faster than the raw substrate.

Further, you do NOT have to modify your CR when you coat pistons. Although you're adding some material (.0015 - .003), you're also removing some material when the pistons are profiled to receive the coating. Their is likely some miniscule increase in CR but so little it's likely un-measurable.

FYI, generally pistons are coated on the skirts for reduced friction, though most newer style pistons are coming coated already. Some are better than others. Point is, if your pistons have any excessive wear, I do NOT recommend coating them to build tolerances back up. Its snake oil. Skirt coatings are very malleable which is why they will essentially "scuff to fit" in most applications. If the piston to wall tolerance is too big, replace the pistons.

Hope this helps. Below are a few samples of some coated pistons.

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[IDIoit]

you are correct.
i didnt choose my words carefully.
altho im just a little machinist. im no engineer

 

[CCPcoatings]

you are correct.
i didnt choose my words carefully.
altho im just a little machinist. im no engineer

No problem. You had the right idea, you just reversed the terms, which I had to refresh myself on as well, lol....

 

[Clb]

From my meager learning on the subject" sounds like a good idea.
If correct it should help turbo burning piston domes.

I would also like to try some ceramic edged weapons.

 

[riotwarrior]

ceramic has great thermo conductivity.
i deal with ceramics everyday, they are perfect for high heat applications.
.

Correc5 me if I am wrong...however my understanding is the ceramic repels heat off dome of piston keeping it in the cyclinder. Is not the ceramic coating a TERMAL BARRIER coating protecting the domes from damage due to excess heat.

Thus when ceramic coating heasers the outside is cooler...it impedes tramzfer of heat ...

Maybe I am out to lunch but it like an insulator in electrical terms vs a conductor....

JM2CW

Eh but *** do I know

 

[IDIoit]

in my world, (mechanical ceramics) my ceramics receive alot of heat, they can and do heat up,
"repelling" heat isnt a term i would use, but they do shed the heat off very fast.

another reason my customers use ceramics, (Alumina oxide, Beryllium Oxide, and YZTP&YZZP Zirconia)
is that when they do get to insane temperatures, they do not warp or deform unless you get them to their max temp.
around 3000*
Al2O3 melts at 3700 ish degrees F