ceramic coating of the combustion chambers
On The Tree
Joined: Sep 2005
Posts: 102
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From: Suburbs of Detroit
My choices My personal everyday car I have coated valve springs, coated piston skirts and tops (cuz I use a little Nitrous here and there), coated underside of my intake (keeps hot oil off of it), coated my oil pump gears, and inside my valve covers to keep hot oil from bonding to the inside.
My street strip car we coated the crank throws and connecting rods for oil shedding, my springs for longer life, the piston tops and skirts (use lots of Nitrous), underside of intake and valve covers, inside of timing cover for oil shedding, and inside of oil pan to again shed the oil off of it. Trying not to get oil clinging to everything and get it back to the bottom of the pan so it can go to the bearings.
My tow vehicle we coated springs, and pistons skirts. This engine can see some heat with a 350 Chevy towing a race car behind a truck that already weighs 4200lbs. The skirts coating just gets rid of friction and the spring coating to provide longer life.
It all comes down to ones budget and what their plans are, if you run a power adder now or plan to then when you build the motor you build it with that in mind, most of the coatings you would use you can use all the time. If you watch the people who always win the engine master challenge they typically coat everything.
Thanks
My street strip car we coated the crank throws and connecting rods for oil shedding, my springs for longer life, the piston tops and skirts (use lots of Nitrous), underside of intake and valve covers, inside of timing cover for oil shedding, and inside of oil pan to again shed the oil off of it. Trying not to get oil clinging to everything and get it back to the bottom of the pan so it can go to the bearings.
My tow vehicle we coated springs, and pistons skirts. This engine can see some heat with a 350 Chevy towing a race car behind a truck that already weighs 4200lbs. The skirts coating just gets rid of friction and the spring coating to provide longer life.
It all comes down to ones budget and what their plans are, if you run a power adder now or plan to then when you build the motor you build it with that in mind, most of the coatings you would use you can use all the time. If you watch the people who always win the engine master challenge they typically coat everything.
Thanks
Originally Posted by Dart331Stroker
the reflection puts the heat in the chamber this allows the motor to make more power.
On The Tree
Joined: Sep 2005
Posts: 102
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From: Suburbs of Detroit
Heat True compression, if the engine is absorbing all the heat in the chamber then it is losing dynamic compression. Yes we are looking to fill the cylinders with colder air as it enters the engine, but it is leaving over 1300 degrees when it exits the exhaust ports. We monitor this per cylinder both with EGT testing equipment as well as o2 sensors. When we run without piston top coatings we have to totally alter the fuel curve and this takes power out of the engine. Plus piston top coatings keep the thing alive when you run it on the edge of lean, it wont prevent a melt down long term but it will help it live in the short term, and hopefully one will correct it prior to meltdown. Anybody who has run alot of boost, or nitrous who hasnt used coatings should the benefits out way the $16.00 per piston it cost. Remember this heat in the chamber is power. ALWAYS
On The Tree
Joined: Sep 2005
Posts: 105
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From: Detroit - suburbs
The power is made by the heat in the chamber. The deck of the heads and the top of the pistons absorb heat and the left over is turned into power. 'nother reason that super thick decks on heads is not all some think it is. Aluminum is an incredible heat sink and coatings can provide a barrier so that the heads and pistons can reflect the heat into pushing the crank - that makes power.
Gotcha, that's why I said 'prior to combustion' b/c I thought that's what you were referring to. I understand the heat AFTER the combustion is the power and we do want to maintain all of that. We're saying the same thing 
Originally Posted by ArcticZ28
The exhaust ports would be useless to coat. Your main gains from coating would be on the intake valves and pistons. Coating the intake valves allows them to stay cooler, thus not heating up the air from the intake as it passes around into the combustion chamber. Coated pistons would also promote better heat transfer and less heat soak.
sorry but nope.....coating the exhaust ports makes a HUGE difference......exhaust gases are upwards of 1600+ degrees......aluminum transfers heat really well.......1600degrees + aluminum ports = heat transfer into the cylinder head/cooling system/etc. instead of going out the port.....
with coated ports the engine will run cooler and the exhaust gases will hold more energy and as such scavenge better.....
my 388 all bore I built was coated on the following surfaces.....
ceramic:
- piston crowns
- chambers
- intake valve face
- exhaust valve face AND back
- exhaust ports
tefflon:
- valve guides
- piston skirts
with this, in 110degree AZ summers with the AC on, the engine never goes above 170 (water temp) and 180 (oil temp), even at WOT (this is with a stock radiator and an external oil cooler....the old 400rwhp head/cam engine with the SAME cooling system would do 190water/210oil under the same conditions)........the heat is used to push the pistons down the bore, then goes out the ports keeping the engine cool.......
ANY engine I ever build from now on will be coated.......(I'm lucky in that there is a local place in Phoenix that does coating so it is quite a bit cheaper that having to send the parts off)
Good to know, didn't realize that.
BTW, been wondering, does anyone still Jet-Hot coat the inside of their headers/exhaust? I remember that old nascar trick but haven't really heard much about it in use other than that.
BTW, been wondering, does anyone still Jet-Hot coat the inside of their headers/exhaust? I remember that old nascar trick but haven't really heard much about it in use other than that.
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Originally Posted by ArcticZ28
Good to know, didn't realize that.
BTW, been wondering, does anyone still Jet-Hot coat the inside of their headers/exhaust? I remember that old nascar trick but haven't really heard much about it in use other than that.
BTW, been wondering, does anyone still Jet-Hot coat the inside of their headers/exhaust? I remember that old nascar trick but haven't really heard much about it in use other than that.
I think Jet-Hot coats all their headers inside and out........otherwise they would rust from inside out.........
Originally Posted by ArcticZ28
Hmmm... I just thought it was the outside to keep heat from dissipating into the engine bay and obviously for durability.
It is my understanding that it helps keep the heat in the header thus improving exhaust gas velocity which would also aid in cyl. scavenging.
TECH Fanatic
Joined: Mar 2003
Posts: 1,384
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From: Jersey boy
these may be stupid questions but here it goes anyway: how come ceramic coated headers have the coating flake off and cylinder heads wont? i saw someone saying they have to be cleaned perfectly but does that mean theres noone out there coating headers who knows how to clean them?
also, ceramic is not a very flexible material, how could you coat something with such a large coefficent of expansion as aluminum and not have it seperate when the aluminum expands? For that matter how can you coat springs and not have it flake off when they compress?
is some different type of ceramic or what?
also, ceramic is not a very flexible material, how could you coat something with such a large coefficent of expansion as aluminum and not have it seperate when the aluminum expands? For that matter how can you coat springs and not have it flake off when they compress?
is some different type of ceramic or what?
Teching In
Joined: Sep 2004
Posts: 7
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I've sent alot of coating work to Omar at Dart. He has been in the engine coating bussiness for a very long time, and works with the top names in the business day in and day out. I've never had a single issue with any of his work, and he is great to deal with.
Originally Posted by BigPlanTransAm
these may be stupid questions but here it goes anyway: how come ceramic coated headers have the coating flake off and cylinder heads wont? i saw someone saying they have to be cleaned perfectly but does that mean theres noone out there coating headers who knows how to clean them?
also, ceramic is not a very flexible material, how could you coat something with such a large coefficent of expansion as aluminum and not have it seperate when the aluminum expands? For that matter how can you coat springs and not have it flake off when they compress?
is some different type of ceramic or what?
also, ceramic is not a very flexible material, how could you coat something with such a large coefficent of expansion as aluminum and not have it seperate when the aluminum expands? For that matter how can you coat springs and not have it flake off when they compress?
is some different type of ceramic or what?
first of all, springs are not ceramic coated....they are coated with a Teflon like stuff that helps with friction (ie: heat), same with piston skirts, rods, cranks, etc....
the parts to be ceramic coated are sand blasted (the area to be coated that is) before the coating is sprayed on to allow the coating to adhere otherwise it would flake off......once heat cycled you can not chip the stuff off with a hammer and chiseled (can't even really sand it with sand paper....must be ground/machined off).....the ceramic used inside engines is much different than what is used on headers (its ugly gray or brown and very rough but man does it work).....
On The Tree
Joined: Sep 2005
Posts: 102
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From: Suburbs of Detroit
Coating I agree with the last few post, the ceramic used on headers is much different. It is truely more of a ceramic material in its properties. The ceramic coating in a motor is very different and has a moly base also. It is also prepped differently. Ceramic header coatings can last forever depending on their application. Mine have been used for years without any discoloration, rusting, or flaking. I have seen other street cars where they fail within a year or two. It has alot to do with who did them, how they were done, and temperatures. Ceramic coated headers dont like excessive EGT's and it will discolor and break the ceramic down, and it wont adhere to the pipes. But in comparison to painted headers they last a lot longer in the same environment. We use HPC here for that style header coating, and we like their finish and quality. We have also done some of the ceramic coating on headers like the stuff we use on piston tops, its kind of olive/gold in color and not attractive but it works for what we do.
Originally Posted by ArcticZ28
Gotcha, that's why I said 'prior to combustion' b/c I thought that's what you were referring to. I understand the heat AFTER the combustion is the power and we do want to maintain all of that. We're saying the same thing
Originally Posted by Armageddon
Thermal Efficiency
yep......thermal efficiency, thermal rejection of the material, and breathing efficiency are what HP it all about.....
I always said the racer's wet dream would be:
- a "plastic" engine that had 100% thermal rejection (ie: even after running for hours at WOT the parts were still be a room temp.....they wouldn't take up any heat) and as such you wouldn't need ANY cooling system, you wouldn't have any parts expanding/warping (you could run closer tolerances), and all that heat that usually gets "lost" through those paths could....
- be used to run a 100% thermal rejection turbo charger so no heat would travel through the turbine housing into the compressor housing.......
I saw that you said that it was $16 a piston. To keep the engine lasting longer why would this not be more public knowledge. Until this post I have never heard of it. Is it possible to get more pricing. I would remove my pistons, rods, heads oil pump and what ever else for similar prices like the ones for the pistons.
I will remember this and will do this from now on when I build an engine.
I will remember this and will do this from now on when I build an engine.