Tim Benton

iTrader: (1)

oh, now that I can't see on my ruler and I agree the compression more than likely wouldn't go up with that thin of a layer. How come we haven't heard of many race teams doing this, here or in Japan?
How much are we looking at for the level of quality Kento is referring to?

Tim

Flybye

Do some research on the 26b in the 787b.

I forgot which were coated, but either the rotors, housings or endplates were coated. I don't feel like looking for it now cuz I'm tired and sleepy

jimlab

One thing to consider is that the heat of combustion has to go somewhere...

The heat of the rotors is transfered into the oil passing through the rotors. If you block that heat with a ceramic barrier, the heat has to go somewhere else. That "somewhere else", unfortunately, is the rotor housings and/or end plates, and ultimately the cooling system. Which, as we all know, doesn't really have the capacity to deal with much more than it's already burdened with.

It's a fairly delicate system. If you make a change somewhere, you run the risk of getting results other than what you expected. Personally, I wouldn't mess with it. I doubt it's worth any power, and the downside could be elevated coolant temperatures.

DaveW

Because of the short residence time of the combustion products in the combustion chamber, the vast majority of the combustion heat goes into creating power (expansion of the burnt gasses) and out the exhaust into the turbos. Therefore, I would expect very little change in rotor housing temperatures and cooling requirements, but a slight increase in BMEP (HP) and boost pressures.

rotaryhardcore

A better investment might be rebuilding the engine with ceramic seals. I think this IS fairly common in Japan.

-C

DamonB

That has nothing to do with ceramic coating the cumbustion face of internal engine parts.

As DaveW pointed out the less heat that the engine absorbs from the combustion event the more efficient the combustion is (more efficient combustion=more power). That is exactly why such coatings are used in high performance applications. Seems something like 50% of the energy in a modern internal combustion engine is wasted as heat. Ceramic coatings of internal combustion parts is an attempt to get some of that back.


Any extra heat is going to go out the exhaust port, not make coolant temps sky rocket.

Brad

http://www.performancecoatings.com

BATMAN

Good point.

Since my radiator has been upgraded it's my best guesstimate that this should be sufficient in handling a greater load on the cooling system.

I'm just not sure if the rotors are effecient in their cooling properties with oil since the rotors seem to have so much metal. Heat transfer from the rotor to the oil may not match the amount of heat that is radiated to the rotor during the combustion event.

It's just a thought.

Anyone care to elaborate on this?

BATMAN

there is another company that does coatings for the space shuttle and even rotors that my supra buddy is using for his MK4 engine.

I think it's swain technologies.

Has anyone had experience with them?

Shinobi-X

I believe it's more like 70%, and slightly greater for rotary engines.

DamonB

Still not the same stuff you put on pistons, etc. Here is what you want: Thin Air Look under "Internal Engine".

From the site:

"CBX Powerkote

Designed for Performance engines - Nitrous Oxide, Supercharged or Turbocharged.
Creates a hard surface specifically designed for engine running high volumes of fuel and/or high compression ratios.
Thermal barrier coating.
Reduces part temperature. Keeps heat in the combustion chamber longer through the power stroke.
Increases torque and H.P. Increase combustion chamber efficiency. "

DamonB

Wouldn't suprise me; I couldn't remember the numbers. I just know it's obscene! And the rotary is absolutely less combustion efficient than a piston motor, unless the piston motor is hideously oversquare.

Shinobi-X

As far as being sufficient, what other mods do you have that would affect the radiators cooling ability? Just asking, because replacing the radiator by default, doesn't really add any extra cooling ability.

Do you mean other than normal engine temp conditions? Perhaps oil modifications, as well as those to the cooling system would offer the greatest assistance then.

Also passing thoughts, it seems as if you are just taking a greater load off the oil cooling system. In combination with Jimlabs post, and a quote from the site: "Piston *rotor* temperature and horsepower are interrelated. High horsepower per cubic inch engines not only make more horsepower, but they make more heat. How the excess heat is handled has a significant effect on total engine power and longevity.", I'm curious to know what percent in heat reduction the rotors would see, and along with that, at what percentage it becomes significant for performance/engine protection.

DamonB

The less heat that is transferred from the burning of the fuel/air mixture into the engine components themselves the better; that's the entire point of high temperature ceramic coatings. As you know ceramics are very good insulators, so they help inhibit the ability of the heat from combustion to transfer into the engine parts; thus making combustion more efficient.

BATMAN

The reduction in heat transfer of the coating like JETHOT is roughly 20 - 35%.

I don't know details on the other coatings that may be more appropriate for this application if it is indeed a good fit.

The goal is to reduce the carbon buildup and surface temps on the rotor face where I suspect most of the detonation occurs since I would assume that it doesn't have the luxury of coolant passages as in the case with the rotor housings.........

BATMAN

Also the thought of coating the outside of the engine block and other heat related components may lend itself to longer life on rubber hoses, wires and other materials that may deteriorate due to high heat.

Andrew

iTrader: (1)

Give these people a call: http://www.swaintech.com/

SCC used several of their coatings on their 500+ rwhp 300ZX engine.

jimlab

Yep.

My pistons have dry film lubricant on the skirts and GoldCoat ceramic heat barrier coating on the crowns.

Sesshoumaru

iTrader: (1)

I though you would want a somewhat uneven surface (not polished). This was to help the fuel atomize.

I wanted to polish the rotors for the same reason but my friend said something about it wouldn't atomizes the fuel as well.

Brad

Yes, they do have the same stuff you put on pistons.

They have various forms of dry film lubrication and film impregnation.

Maybe you didn't check the site out? Here, let me help you:

http://www.performancecoatings.com/enginecoatings.html

BATMAN

Jim,

mind if i ask u what that cost u?

turn around time?

Kento

Heat reduction in the rotors, easing the oil temps, and engine protection are just by-products of this whole idea; they're almost irrelevant. The whole point is reducing the amount of heat that gets absorbed by the combustion chamber metals. By reducing that heat absorption, you allow more of that heat energy to focus on propelling whatever reciprocating components are responsible for hp production. That is how "the excess heat is handled."

Jim does have a point, but I agree with DaveW-- I think that more of the energy (heat) will be used for power production than be absorbed by the end plates/rotor housings. Their plated surface helps them with heat rejection; for instance, in piston engines, when serious detonation occurs, the first components to get "eaten" by the process are the piston and cylinder head.

Kento

Again, I think those are by-products of the ceramic coating process, not the real goals. And detonation isn't caused by the surface temp of the rotor face; it's caused by overly lean a/f ratios burning in an uncontrolled manner due to spontaneous combustion resulting from compression. Pre-ignition can be caused by carbon build-up, but I doubt that's the case with most problems associated with rotary engine frags.

Kento

That is a bad idea, because the whole point of these coatings is to reject/retain heat for power production in the combustion process. In this case, you'll be retaining heat in the engine core that could be radiated off otherwise (even though it's a relatively small amount compared to the coolant system). Every possible way to get rid of heat counts. The possible benefits as far as underhood heat would be minimal in comparison.

jimlab

$42/each (Dome GC and Skirt PC-9). http://www.swaintech.com/price.html

I don't know for sure, because I wasn't directly involved, but compared to other parts of the build-up, JE kicked out my custom pistons extremely fast it seemed, and they were coated and back at B&B Performance quickly too.