Dart Coatings

[Dart Vader]

Whether it's on an engine you've built or one you've had built for you, we'd like to know if you've used Dart coatings in the past.

[Dart Vader]

There was an issue with the way I initially posted this poll that wouldn't allow anyone to vote!

This has been fixed...

[Trmnatr]

Whether it's on an engine you've built or one you've had built for you, we'd like to know if you've used Dart coatings in the past.

Do the coating materials come from NIC, Techline or what ?

It seems as if alot of people that run very high compression with tight quench and alot of RPM prefer Techline Thermal Barrier coatings {not the ones available to the public} from what i see, Skirt coatings seem to be the same from Polydyn, Dart, and Calico

What TEMP does Dart bake the following {most popular} at:
-Thermal Barrier
-Skirt Coatings
-Oil Shedding

Dart Vader, Can you e-mail me bandbengines@yahoo.com and leave the subject line coatings ? Thanks

[Dart Vader]

I can e-mail you, but I'll answer here also - just so the curious can read too.

Our coating materials are created in house, we don't get them from an outside provider.

Concerning the Techline thermal barrier, it really just depends who you ask. Their formula uses an aluminum base, which starts to weaken at around 1100 degrees and is usually finished at about 1600 degrees. We've been working on our formula (Pro-stock uses it) and it stays effective even at around 2500 degrees.

The skirt coatings are actually not the same from Polydyn, Calico, or from us - all use different formulas.

Finally, the baking temps all have a range because we use different temps based on the material being coated, but here are the ranges:
Thermal Barrier: 300-600 degrees
Skirt Coatings: 300-350 degrees
Oil Shedding Coatings: 200-350 degrees

[Trmnatr]

I can e-mail you, but I'll answer here also - just so the curious can read too.

Our coating materials are created in house, we don't get them from an outside provider.

Concerning the Techline thermal barrier, it really just depends who you ask. Their formula uses an aluminum base, which starts to weaken at around 1100 degrees and is usually finished at about 1600 degrees. We've been working on our formula (Pro-stock uses it) and it stays effective even at around 2500 degrees.

The skirt coatings are actually not the same from Polydyn, Calico, or from us - all use different formulas.

Finally, the baking temps all have a range because we use different temps based on the material being coated, but here are the ranges:
Thermal Barrier: 300-600 degrees
Skirt Coatings: 300-350 degrees
Oil Shedding Coatings: 200-350 degrees

Thanks for the temps

[BIG CHIEF]

Thought this would be cool to post here also:

http://www.dartheads.com/products/dc-5-oil-shedding-coating.html?video=1

[Trmnatr]

Thought this would be cool to post here also:

http://www.dartheads.com/products/dc-5-oil-shedding-coating.html?video=1


Has there been any back to back testing done with any non coated parts then coated ?

My concern with thermal barrier coatings is where does the increased heat go,,,

-into the cylinder wall to make it weaker ?
-into the chamber trying to push it into detonation ?
-into the valves causing failure due to heat ?

Are the above possible if the tops of the pistons are coated and not the chambers and valves ?

How much HP, if any or part lift, out of thermal barrier top coatings?

Also, in the video Mr. Richard Maskin had a coated piston that was gold but shiny,, Why is the Dart TBC not shown as shiny on the others?

Did that piston have a special coating over top of it ?

[BIG CHIEF]

Yes, there have been a number of back to back tests that have shown gains in our prostock engine development. One reason this Zirconium based ceramic coating is used, is to reduce engine oil temps and reduce the overall heat that sinks into the engine block, cylinder walls, cylinder heads and eventually the manifold.

Now the question is “were does the heat go”?

A small percentage of heat is dissipated into the chamber which is a heat sink during the combustion process. This allows the cooling system to perform its main function by carrying the heat out and expending it / dissipating it through the radiator.

The other large percent of heat that is left is actually expended through the exhaust port and used to help create rapid expanding gasses to manufacture higher exhaust velocities. Now these gasses / velocities can be used in a number of applications.

1. Naturally aspirated engines that use scavenging during valve overlap to help draw intake charges into the cylinder creating higher dynamic cylinder pressures.


2. In Turbo applications the heat / rapid expanding gasses will create more pressure to spool turbos at a higher rate/ efficiency.

In most of these applications we recommend that the exhaust valves should be coated also with the same heat reflective material. This is due to the extra heat that is being squeezed passed the valve during the heat cycle.


Now horse power gains can be debated all day long and still no one will have a true answer. I would like to put a HP number on this coating process for you, but due to so many variables in so many different types of applications… I just can’t say. I am pretty sure you will agree with this statement. I do know that there are increases to be had by using the available heat that’s displaced by the coatings and focusing it into specific areas to make HP gains.

The pistons showed in the video were probably polished with scotch brite to help create more of a reflective surface. I have seen our coating tech polish the coatings before in other applications as well.

Let us know if you have anymore questions and I will be more than happy to go over the processes and applications with you.

Thanks,

[Trmnatr]

Yes, there have been a number of back to back tests that have shown gains in our prostock engine development. One reason this Zirconium based ceramic coating is used, is to reduce engine oil temps and reduce the overall heat that sinks into the engine block, cylinder walls, cylinder heads and eventually the manifold.

Now the question is “were does the heat go”?

A small percentage of heat is dissipated into the chamber which is a heat sink during the combustion process. This allows the cooling system to perform its main function by carrying the heat out and expending it / dissipating it through the radiator.

The other large percent of heat that is left is actually expended through the exhaust port and used to help create rapid expanding gasses to manufacture higher exhaust velocities. Now these gasses / velocities can be used in a number of applications.

1. Naturally aspirated engines that use scavenging during valve overlap to help draw intake charges into the cylinder creating higher dynamic cylinder pressures.


2. In Turbo applications the heat / rapid expanding gasses will create more pressure to spool turbos at a higher rate/ efficiency.

In most of these applications we recommend that the exhaust valves should be coated also with the same heat reflective material. This is due to the extra heat that is being squeezed passed the valve during the heat cycle.


Now horse power gains can be debated all day long and still no one will have a true answer. I would like to put a HP number on this coating process for you, but due to so many variables in so many different types of applications… I just can’t say. I am pretty sure you will agree with this statement. I do know that there are increases to be had by using the available heat that’s displaced by the coatings and focusing it into specific areas to make HP gains.

The pistons showed in the video were probably polished with scotch brite to help create more of a reflective surface. I have seen our coating tech polish the coatings before in other applications as well.

Let us know if you have anymore questions and I will be more than happy to go over the processes and applications with you.

Thanks,

Thanks for the reply

So my theory of the exhaust valves taking more heat and maybe a failure is why you suggest that exhaust valves be coated too ?

[BIG CHIEF]

Thanks for the reply

So my theory of the exhaust valves taking more heat and maybe a failure is why you suggest that exhaust valves be coated too ?


Your thoughts are correct to some extent. HP levels and quality will effect this decision. If you are running a cast or low quality stainless valve I would say it would be a good preventive measure to take. This may not apply to a higher quality valve like Inconell or Titanium because of their ability to endure and dissipate higher temperatures.

Also the seating angle and margin will affect the heat transfer rate to the seat and eventually to the cooling system. If you can optimize the valve quality, seating angle and margins, then you may not have to use coatings at all on the exhaust valve.

Let me know if you have anymore questions?

[Trmnatr]

Your thoughts are correct to some extent. HP levels and quality will effect this decision. If you are running a cast or low quality stainless valve I would say it would be a good preventive measure to take. This may not apply to a higher quality valve like Inconell or Titanium because of their ability to endure and dissipate higher temperatures.

Also the seating angle and margin will affect the heat transfer rate to the seat and eventually to the cooling system. If you can optimize the valve quality, seating angle and margins, then you may not have to use coatings at all on the exhaust valve.

Let me know if you have anymore questions?

Here is one article i found,,,,
http://www.hotrod.com/techarticles/engine/hrdp_0612_engine_coatings/index.html

with anti-friction coatings and oil shedding coatings they lost a hint of hp and lost 5.3 tq

with anti friction coatings, oil shedding coatings, and thermal barriers the engine gained 8.1hp and 6tq

it looks like all the coatings were $849
http://www.hotrod.com/techarticles/engine/hrdp_0612_engine_coatings/photo_21.html

Blower Test Summary
http://www.hotrod.com/techarticles/engine/hrdp_0612_engine_coatings/photo_22.html

[Trmnatr]

Here are some comments from Hot Rod on the different coatings in the next few posts which all of these are in the links above,, could you guys comment on them?

It looks as if they expressed the same thing about thermal barrier coatings that i
did also

Thermal Barriers
In theory, heat management offers great potential for improving an engine's power output. Often, ceramic-based thermal-barrier coatings (TBCs) are used to reduce heat migration, reflecting heat rather than absorbing it. They may be applied to piston-top surfaces and top ring grooves, combustion chambers, exhaust-valve heads and faces, exhaust manifolds and headers, and inside exhaust ports.

When applied to piston tops, TBCs reflect heat back into the combustion chamber. The additional heat translates into more energy to push the pistons down. To the extent coating the piston tops makes the top surface smoother and minimizes the development of local hot spots on the pistons' surfaces, TBCs may decrease detonation potential. On the other hand, TBCs may prevent heat from dissipating down into the pistons and rings, through the cylinder wall, and into the water jacket; this may actually increase detonation potential. The tilt point is related to whether the engine will be subjected to heat over a long period (as in an endurance motor) or in short bursts (like a drag-race car). Consult your piston manufacturer for specific application advice.

Setting up a thermal barrier in the combustion chamber also helps the chamber retain heat for more power potential. Again, assuming detonation does not become a problem, this can increase combustion efficiency while lowering engine-coolant temperatures. Aluminum heads, which are said to reject heat quicker than traditional cast iron, may see particular benefits from TBCs. Barriers can also be applied to valve heads to keep them cooler.

Coating the inside and outside surfaces of exhaust parts with TBCs is said to increase exhaust-gas velocity, reducing backpressure and reversion. Coating the inside of a mild-steel header smoothes the surface by eliminating corrosion and scale, which should also enhance flow. Coating the outside should reduce ambient temperature, which may result in an overall temperature decline within the engine compartment.

[Trmnatr]

Lubricity Coatings
Lubricity or antifriction coatings consist primarily of dry-film or solid-film lubricants that reduce friction, galling, and seizing. In some instances, this category can also help disperse heat. These coatings typically contain molybdenum disulfide or tungsten disulfide. The application method and binder technology are critical in getting the coating to stick to the metal surface in long-term use.

In the engine's bottom end, dry-film lubricants are usually applied to piston skirts, engine bearings, and the main and rod journals. On the top side, dry-film lubricants are sometimes applied to valve stems, rocker arms, pushrods, lifters, valvesprings, and cam lobes. Under heavy loads, moly-based dry-film lubricants can actually hold oil on their surfaces, enhancing the integrity of the oil film between the metal parts. These same lubricants can delay metal-to-metal contact if oil pressure is lost. Although some claim that by reducing friction, lubricity coatings should offer some power gains, normally an engine's journals and bearing surfaces are separated by the oil film and never come into contact, so it's hard to see how coating the bearings would add any power under standard operating conditions. Therefore, the main advantage is really as an insurance policy, enhancing longevity and providing emergency protection if something goes wrong.

Lubricity coatings also lower a part's temperature. Applied to upper-end parts like valvesprings, they can greatly extend their fatigue lives. Some builders claim a 15- to 30-degree oil-temperature drop, which could permit using thinner oils without compromising parts longevity. Thinner oils offer less drag, which may translate into increased power.

[Trmnatr]

Oil Shedders
Usually based on PTFE (Teflon) or similar fluoropolymers, oil shedders, as their name implies, help a part shed oil to improve crankshaft windage and oil return. They are usually applied to the undersides of pistons, connecting rods, crank counterweights, windage trays, and the insides of oil pans, timing covers, and valve covers-anyplace oil isn't needed. Shedders may improve overall high-rpm engine lubrication while reducing oil temperature and can also help reduce varnish, sludge buildup, and corrosion. To the extent shedding oil may cut drag on rotating parts, power benefits are also claimed.

[Trmnatr]

Thermal Dispersants
These are the opposite of heat barriers: They radiate or disperse heat. As previously stated, keeping heat in the chamber is good provided you don't get into detonation. But if you do have a detonation problem, a dispersant could be in order. Many thermal dispersants are dual-category products. Besides their antifriction properties, dry-film lubricants often disperse heat (their use on valvesprings would be one example of dual-category use). Other, proprietary, thermal dispersants take the place of traditional black paint and are sometimes applied to brakes, intake manifolds, cylinder heads, oil pans, radiators, and intercoolers.

[Trmnatr]

Corrosion Inhibitors
Corrosion is not just a cosmetic blemish. It weakens and destroys parts. Headers rust out. Aluminum intake water passages can corrode, especially on a salt-water boat. Exotic fuels like alcohol and nitromethane are also highly corrosive. A variety of coatings and electrochemical plating media exist for fighting corrosion while enhancing a part's appearance. Again, some of these coatings may have additional thermal-barrier or thermal-dispersant properties.


CAN YOU COMMENT ON WHICH COATINGS YOU FALL UNDER WHICH SECTION OF TBC'S ETC AND USAGE ? ALSO, HOW ACCURATE IS THIS INFORMATION ? I WOULD ASSUME PRETTY ACCURATE AS IT WAS IN HOT ROD

What is the advantage of polishing the gold thermal barrier coating ? How does Mr. Richard Maskin do it (polish the TBC) ? Whats the advantage to polishing a TBC ?

THANKS

[Trmnatr]

Corrosion Inhibitors
Corrosion is not just a cosmetic blemish. It weakens and destroys parts. Headers rust out. Aluminum intake water passages can corrode, especially on a salt-water boat. Exotic fuels like alcohol and nitromethane are also highly corrosive. A variety of coatings and electrochemical plating media exist for fighting corrosion while enhancing a part's appearance. Again, some of these coatings may have additional thermal-barrier or thermal-dispersant properties.


CAN YOU COMMENT ON WHICH COATINGS YOU FALL UNDER WHICH SECTION OF TBC'S ETC AND USAGE ? ALSO, HOW ACCURATE IS THIS INFORMATION ? I WOULD ASSUME PRETTY ACCURATE AS IT WAS IN HOT ROD

What is the advantage of polishing the gold thermal barrier coating ? How does Mr. Richard Maskin do it (polish the TBC) ? Whats the advantage to polishing a TBC ?

THANKS

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