Ceramic coating and heat discussion

[FordNut]

Let's start with some fundamentals and expand from there.

Background:
According to what I learned in thermodynamics, heat transfers from high temperature to low temperature. With bare steel headers, heat transfers from high temperature exhaust gases to the steel, through the steel and then to the air in the engine compartment. The way I understand it, when caramic coating is applied to headers, it is normally applied to both the inside and outside. The coating on the inside reduces the amount of heat transferred to the steel, then the coating on the outside further reduces the amount of heat transferred to the air in the engine compartment.

Effect:
The reduced heat transfer has several effects. It keeps the exhaust gases hotter, which heats the catalytic converter better, making it perform better and allowing it to be mounted further from the heat source (the exhaust valves, or technically the combustion chamber). It also keeps the velocity of the exhaust gases higher due to the reduced density associated with thermal expansion. This high velocity supposedly improves scavenging with long tube headers. The fact that the heat is not transferred through the walls of the headers to the air in the engine compartment helps to keep the intake air cooler and more dense. More dense air has more oxygen in a given volume, which increases performance. The reduced engine compartment temperature has another side benefit, in that the plastic parts in the engine compartment stay cooler and last longer without becoming brittle.

Hypothesis:
Now we get to the new stuff. I believe some performance gains could be had by ceramic coating the intake manifold, particularly the upper intake.

Heat is transferred to the aluminum from a few sources, one being the engine compartment air which is already at a lower temperature due to the ceramic coated headers but could be further insulated with ceramic coating on the outside of the upper intake.

The EGR valve and ports are a second source, which is potentially the worst source of heat because of the intense exhaust heat. One member has installed a restrictor plate there to reduce the amount of hot gases injected into the intake but that does nothing to reduce that temperature. If ceramic coating were applied to the inside of the EGR ports similar to the inside of header tubes, the same effect should be seen in that the heat transferred to the aluminum would be reduced. Now for a race-only application I suppose the EGR could be totally eliminated but that would not be wise or legal for a street driven car.

A third source of heat is the water connection near the connector for the PCV tube. This has been bypassed by one member, and that could be a good thing for short term in that it removes the 180 degree water from the intake and keeps the aluminum cooler. But I believe that it has a possible negative effect in that the very high temperature from the EGR valve and ports could heat the intake well above the water temperature, then the only place for the heat to go is to the air, both in the engine compartment and inside the intake. I feel that a better option would be to cool the water even cooler than the normal 180 degrees before it goes into the intake.

Whatever the temperature of the aluminum, ceramic coating on the inside of the intake should help reduce the heat transfer from the metal to the air inside the intake. I do not believe the lower intake has any water passages or EGR ports so it would probably not benefit as much form ceramic coating as the upper intake, if at all.

Question:
So somebody explain the flaws in this line of thought. If nobody has a good argument as to why it would not work this way and improve performance, I may try it.

[Zack]

I wish your post had cliff notes.
Do not ceramic coat the inside of any intake manifold ever!!
You may not know this, but the surfaces of any intake manifold (inside) must stay a little rough. There are certain tools a cylinder head porter uses to achieve this. The reason for this 'rough' surface is to atomize the fuel and air while traveling toward the cylinder head. Basically what happens is the rough, usually spiral like grooves causes the fuel and air to 'spin' inside the manifold, causing the two to mix very evenly before combustion.
Ok? Stop thinking about it!!

[FordNut]

I wish your post had cliff notes.
Do not ceramic coat the inside of any intake manifold ever!!
You may not know this, but the surfaces of any intake manifold (inside) must stay a little rough. There are certain tools a cylinder head porter uses to achieve this. The reason for this 'rough' surface is to atomize the fuel and air while traveling toward the cylinder head. Basically what happens is the rough, usually spiral like grooves causes the fuel and air to 'spin' inside the manifold, causing the two to mix very evenly before combustion.
Ok? Stop thinking about it!!

Well, since the injectors are at the intake ports, there is only air in the upper intake. So the only reason I can see not to do it would be the possibility of flaking. But it stays on headers so why wouldn't it stay on an intake.

[Petrograde]

You had me until you mentioned coating the intake. I would think that it would have the opposite effect that you are looking for, by trapping heat near the injectors I'd think you'd run the chances of pre fuel detonation. Even if the engine compartment was cooler from coated headers. But, I'm just a wrench turner,.. not an engineer. My logic may be flawed too..

BTW- that was a well written post. I haven't read anything that technical since I was studying for my Airframe & Powerplant license! :lol:

Tom

[Zack]

Well thats a fair question.
If youve ever seen the underside of the upper intake like I have it is basically a cap for the lower intake. The lower would be the one I pay most attention to.
But remember Dennis had a fully extrude honed upper and lower intake on his car, dyno tested it and reported minimal if any gains.
Something to think about.

[FordNut]

You had me until you mentioned coating the intake. I would think that it would have the opposite effect that you are looking for, by trapping heat near the injectors I'd think you'd run the chances of pre fuel detonation. Even if the engine compartment was cooler from coated headers. But, I'm just a wrench turner,.. not an engineer. My logic may be flawed too..

BTW- that was a well written post. I haven't read anything that technical since I was studying for my Airframe & Powerplant license! :lol:

Tom

Well, I guess the heat in the lower intake could be an issue, but the gasket between the upper and lower intake already insulates the two from one another somewhat. Isn't the primary source for heating and/or cooling the lower intake the sealing surfaces to the heads? If so, then maybe ceramic coating only the inside of the lower intake (and maybe the upper intake too) would allow heat transfer from the exterior aluminum surfaces to the air in the engine compartment but insulate the intake air from the hot metal surfaces?

[Petrograde]

If youve ever seen the underside of the upper intake like I have it is basically a cap for the lower intake. The lower would be the one I pay most attention to.

here: I just took these...

Tom

[FordNut]

I wish your post had cliff notes.

On re-reading I saw that it was difficult to follow and edited for easier reading.

[Petrograde]

Well, I guess the heat in the lower intake could be an issue, but the gasket between the upper and lower intake already insulates the two from one another somewhat.
I don't think that gasket insulates too much, granted it cuts down on the heat transfer from upper to lower intakes,... but,.. there's still a lot a really hot air that would have no way to bleed out.


Isn't the primary source for heating and/or cooling the lower intake the sealing surfaces to the heads?
:lol: don't make me lie to ya.... I haven't a clue.


If so, then maybe ceramic coating only the inside of the lower intake (and maybe the upper intake too) would allow heat transfer from the exterior aluminum surfaces to the air in the engine compartment but insulate the intake air from the hot metal surfaces?
hmmm,... I think I see where you're coming from,... But, I personally wouldn't take that chance,... unless you know someone who could model the thermodynamics in a computer.

Tom

[FordNut]

I don't think that gasket insulates too much, granted it cuts down on the heat transfer from upper to lower intakes,... but,.. there's still a lot a really hot air that would have no way to bleed out.

Not really sure what/where the hot air is you're talking about. Inside the intake, it's all going in the combustion chambers. Outside, it should be going to the air instead of the upper intake.


hmmm,... I think I see where you're coming from,... But, I personally wouldn't take that chance,... unless you know someone who could model the thermodynamics in a computer.

Tom
I guess I need to measure the underhood temps and see if the air temp is above or below the water temp. Also I'll measure the surface temps of the intake surfaces. I should be able to model it roughly with those data points. Gotta get out the textbooks and review a little. More importantly is how effective an insulator is the ceramic at the temperatures of the intake. I know it's very effective at the temperature of the headers, as I've touched them.

[Silver_04]

Would changing the color of the intake be beneficial-perhaps to as close to a black body as possible. We use anodized black convectors on many products at work and the gains are noticable over an unanodized surface. I'll have to get the emissivity of cast aluminum.

Edit-For reference the emissivity of polished Al is 0.03 and anodized Al is 0.84.

[Heavy351]

Silver '04 has the right idea, There are coatings available to draw away the heat from parts by increasing the emissivity of the surfaces (increasing the convection coeficient). Ceramic coatings behave in the opposite way acting like a barrier preventing themal energy from passing through. Coating the inside would make sense if there was significant heating of the air on the way through the intake. To be sure you would have to measure the temp in the airbox and the difference as close to the injector as possible. BUT the flipside of this is that the air cools the upper intake also and if you remove that benefit by sealing the inside in ceramic the intake could rise in temp high enough to have exactly the opposite effect you are looking for. (the ceramic only slows the heat transfer, doesnt stop it). The ideal intakes are very thin having less mass to act as a heat sink, think of sheetmetal boxes and the GT-40 tubular upper intake.

This is also one of the reasons the intakes on the 4.6 2V are made of plastic (I think they are..). they reject heat absorption.

I ceramic coated the tops of my pistons, combustion chambers, valve faces, and the exhaust ports on my World Products Windsor heads years ago. I appied with an air brush and used the oven in my girlfriends apartment (she nearly killed me cause of the smell it left) My water temps showed 15deg cooler and I ran quite a bit more timing as a result...

I bought the coatings from Summit or Jegs I think.

Until somebody can show significant heating of the intake charge, I don't think you will benefit much from the trouble and expense...

[FordNut]

Wow, there's lots of info on the web about this. Guess I should have checked there first. Based on further research, it seems that Silver and Heavy are steering me down the right path. That was the purpose of this thread anyway. Most sites I found recommend three different types of coatings for intake manifolds.

1) Inside surfaces of the manifold, use ceramic thermal barrier coating (like header coating). Keeps the heat in the metal from transferring to the air inside. Also coat the flange surfaces to block heat from the heads out of the metal of the intake manifold.
2) Outside surfaces of the manifold, use ceramic thermal dispersant coating. It's usually black in color and enhances the heat transfer from the metal to the outside air in the engine compartment. I still need to measure some temperatures, if the air temperature is higher than the upper intake temperature I don't see how the heat will go away from the manifold into the air.
3) Bottom surface of the manifold, normally the lifter valley in pushrod engines, use solid film lubricant coating. In addition to providing a thermal barrier, this keeps the hot oil from sticking to the bottom of the intake and heating the intake from the bottom side. I don't believe we have this surface to worry about, but I'll have to check further. Tom, how about some pics of the bottom of the lower intake?

All 3 of these coatings cure at around 300-350 degrees and withstand temperatures up to 1300 degrees.

Oh well, I was hoping to just do the upper, but since the thermal dispersant coating is black I'll have to do the lower too. Looks like a bear to get into some of those intake passages though. Todd, I hear you're next after Tom for the intake powdercoat roundy-round. I need to get in that line now so has anybody spoken up for "next"? What about Logan's? I thought he started another one going around.

[SergntMac]

Bravo, gentlemen! I must say that I am quite impressed with all the presentations here. Lots of thought provoking thinking going on, thank you!

This thread provokes me to recall twist from the late '60s. "Cool cans," were coffee can sized, and contained a fuel line wound into a coil. The theory was to pack the coils with ice, and cool the fuel just before it entered the combustion process.

While you search for a way to reduce temps for the fuel charge path, is it not reasonable to consider reducing the temp of the fuel charge itself? Most of us with blowers are using intercoolers too, which acts to lower the fuel charge temp, why not give it a "boost" by cooling the fuel within the charge?

Your opinions please, I'm not knowledgable on this, but I love to learn.

[Heavy351]

They still make cool cans:

http://store.summitracing.com/productdetail.asp?p=3813

With a carb fed induction system you had the gas sitting in the bowls on top of a hot intake really sucking up the heat. On motors really putting out the big HP #s there was little less danger of running lean at the high RPMS using the ice filled cans along with other richer mixture benefits.

I have not heard of anyone using these for a fuel injected setup yet. In fact, the "warnings" link on the page above says "Not recommended for high pressure fuel injection systems".

I suspect on modern EFI systems there is not nearly the problems with the heat as the lines are held away from the motor and/or wrapped with thermal tape (I have not looked at mine but I would at least check for this first) Or you could consider using heat dissapating Aluminum fuel rails:

http://store.summitracing.com/productdetail.asp?p=4944

They have a larger ID to flow more but since they are larger in mass than the thin tubing on the car already, I suspect they might be worse for heat absorption.....

[cyclone03]

Heres something else to think about...
What about just polishing the inside of the intake?This would reduce the area for the air to pick up heat from the manifold.Being the intake is dry(ie:no fuel)mixture turbulance is not a factor.
I know from his post that Dennis' ported intake didn't produce very impressive results but I wonder if the charge temp was down?


As for "cool cans" I haven't seen one on an injected engine,and i spend a lot of time at drag strips.

Truth is cold fuel is harder to atomize so it's kind of counter productive.
What it did back in the day was cool the carburator which helped cool the intake air.

BTW raising the pressure of the fuel to the 40 or so psi required to run a NA engine,not to mention the 80+psi the blown guys may run adds a lot of heat to the fuel.

[Petrograde]

Tom, how about some pics of the bottom of the lower intake?

here ya go!

Tom

[TAF]

Tom...YOU ARE THE MAN!!!!!

You have been the "Tommy-on-the-spot" with the pics of the intakes...





Now...enough with the car parts...got any nekkid women?? :P

J/K Folks...

[Petrograde]

Tom...YOU ARE THE MAN!!!!!

You have been the "Tommy-on-the-spot" with the pics of the intakes...

Just doing my part! :lol:

Now...enough with the car parts...got any nekkid women?? :P

J/K Folks...

yes I do! :D don't tell my wife! :lol:

Tom

[Heavy351]

here ya go!

Tom
Those shots are so bizzare!

Are the round sections something that are closed up later after some internal machine work or something? werd..

[Fast4Door]

While there can be a benefit from reducing heat transfer to the intake air charge, I wouldn't expect a big gain for the expense and hassle. My limited experience with engines on dynamometers indicates an improvement at lighter loads and lower engine speeds, mostly in fuel economy. Basically, the cooler air lets you put in some more part load spark before hitting detonation.

Remember that at WOT you are moving a lot of air through the engine. It doesn't spend much time in the intake, so the heat transfered is small. You'll get more of an effect from the temp of the cylinder head surfaces.

The most effective way to reduce air charge temperature is to cool the air BEFORE it gets in the intake. I'm sure most everyone on the board has felt the increase in performance in the evening (70 deg) compared to the afternoon (85 deg). Since most of us can't control the outside air temp, maybe we can put some efort into a high capacity, portable refrigeration unit.

[SergntMac]

So, I presume that cooling the fuel with a "cool can" isn't anything we would want to consider as a carry over from the "old days." Ummm...Okay. Just thought I'd throw it out here. Thanks, y'all. Seemed kind of messy to me anyway, with all that melted ice having to go somewhere. Please keep exploring this, I'm catching up real fast.

[BillyGman]

Well I don't know a real lot about this issue either, and I understand what people are saying here that using cool cans aren't supposed to be any good for the pressurized fuel in fuel injection systems, but as far as the ice melting too quickly, you can always use dry ice instead. That will last a good part of the day while you're at the track. but probably not very practical for every day driving. I believe dry ice is also very expensive too.

Don't mind me........I'm just thinking out loud.......

[PhastPhil]

How about looking at this from another angle. Fast 4 door's last sentence made me think of it. I beleive Ford's SVT addressed some of this with their latest Lightning concept vehicle. They used the truck's air conditioning system in order to store some ice cold air, and then release it into the intake system creating an effect similar to nitrous. It is good for about a 30 second blast. I think this is one of the ways they can beat the Dodge SRT-10 truck. Does anybody know more about this sytem?

[BillyGman]

Yeah, I forgot all about that. But now that you mention it, I remember reading something about that. And a 30 second blast would be more than enough to win any race of even over 1/2 mile.

[Ross]

I think I have the solution. Permanently mount a beer cooler, powered by a 12 volt system, in place of the console. Re-route the fuel line and air intake through the beer cooler on the way to the engine. This way you get everything we want:

1. Cold Beer
2. Cold Air Intake
3. Fuel line cooler.

I'm on my way to the patent office! I hope DR doesn't beat me there! :lol: :beer:

Seriously, this is an very informative thread and I'm learning new things from it, as usual.

[Haggis]

I think I have the solution. Permanently mount a beer cooler, powered by a 12 volt system, in place of the console. Re-route the fuel line and air intake through the beer cooler on the way to the engine. This way you get everything we want:

1. Cold Beer
2. Cold Air Intake
3. Fuel line cooler.

I'm on my way to the patent office! I hope DR doesn't beat me there! :lol: :beer:

Seriously, this is an very informative thread and I'm learning new things from it, as usual.

Ross here is something similar that was posted in another thread.

http://www.mercurymarauder.net/forums/showthread.php?t=8172

[MARAUDERCHICK]

Now...enough with the car parts...got any nekkid women? :P
J/K Folks...
Yeah right Todd.....we ALL know that your NOT kidding!!:D

I couldn't resist!
~Kathy

[FordNut]

here ya go!

Tom

Thanks for the pics. I can't tell for sure, does it look like those big round caps on the bottom side are removable? That would make it much easier to coat the inside of the runners, and would almost be mandatory for any kind of porting (Dennis!??).

I measured some temps today. Used a Fluke 51, type K thermocouple. Outside temp about 70, air temp (with hood closed) in areas near intake manifold varied from 125-142. Kind of funny, at the back it was 130, passenger's side on the front was 125, drivers side was 142. Anyway, without a doubt the air temp is lower than the water temp so heat dispersant coating on the outside of the intake is probably the way to go.

Surface temps of the lower intake were mostly around 140. Only measured a couple of places, as that was what I was in the middle of when the exhaust leak developed. All the rest of the measurements were already done so the heat from the exhaust leak did not affect the data.

Surface temps in the region of the upper intake were most interesting. The temps varied from 120-150. The main surfaces were about 130, same as the average air temp inside the engine compartment. The low points of 120 were at the ports for EGR inlet, while the near highest points were where the EGR valve flange is, which measured 145. So intake air is apparently providing some cooling effect as it scavenges the exhaust gases from the EGR ports. Intake air cooling a part means the heat has to go somewhere: to the intake air. So I believe heat barrier ceramic coating the inside of the EGR port would probably be a good thing. The EGR valve itself was about 150 so heat barrier ceramic coating on the flange where it mounts would probably be good too. The hottest spot on the intake was 148 and was where the water ports connect to the PCV valve port. I'm not sure about the purpose of this device, it could be to keep the oil vapors hot as they go into the intake. But certainly it would keep the intake temperature down if the flange and port which it connects to were coated with heat barrier ceramic coating.

One area that I still need to collect data on is the area under the intake, between the engine block and the bottom region of the intake where the round plugs are. If it's hotter under there, it may be better to coat the bottom with heat barrier, if it's cooler it may be better to coat with heat dispersant coating. For convenience, it would certainly be better to do all the inside and flange surfaces with heat barrier and the outside surfaces with heat dispersant. This agrees with the standard process. It's great when theory and practice agree.

[FordNut]

While there can be a benefit from reducing heat transfer to the intake air charge, I wouldn't expect a big gain for the expense and hassle.

I don't expect much performance gain, but any help would be useful. Ya know, the closer you get to the peak possible horsepower, the more expensive it is to get minimal gains.

But the expense and hassle is not much more than powdercoating. I don't know if powdercoating has any possible detrimental effects, but the ceramic (barrier/dispersant) coatings provide possible gains, and look good too. So you guys that are powdercoating your intakes, this is something else to think about.


My limited experience with engines on dynamometers indicates an improvement at lighter loads and lower engine speeds, mostly in fuel economy. Basically, the cooler air lets you put in some more part load spark before hitting detonation.

More low end torque! Better part-throttle fuel economy! If I can get those and not lose anything on the top end, it sounds great!

[Petrograde]

Thanks for the pics. I can't tell for sure, does it look like those big round caps on the bottom side are removable?

'fraid not,... they are part of the casting

[rumble]

Very interesting post to say the least. Seeing Sarge talk about the 'cooling cans"
that we used to use reminded me of the way we used to paint engine blocks and
heads black for better heat dissipation. I, however, currently, am traveling a different
road, I have just recently got Logan's intake back from the chrome shop and plan to
install it sometime in the next few days. Obviously I'm not looking for performance
gains it's just something I want to do. My feeling is on a casual street motor the heat
gain and performance difference are going to be so negligible as to not even be
measurable, but we shall see. Remember, the proof of the pudding is in the eating.
to be continued..............

[FordNut]

Very interesting post to say the least. Seeing Sarge talk about the 'cooling cans"
that we used to use reminded me of the way we used to paint engine blocks and
heads black for better heat dissipation. I, however, currently, am traveling a different
road, I have just recently got Logan's intake back from the chrome shop and plan to
install it sometime in the next few days. Obviously I'm not looking for performance
gains it's just something I want to do. My feeling is on a casual street motor the heat
gain and performance difference are going to be so negligible as to not even be
measurable, but we shall see. Remember, the proof of the pudding is in the eating.
to be continued..............

So you're the one with the other spare intake. Who is next in line? I need to get in line for one of these, either this one or Tom's (anybody else with a Trilogy want to start a chain or just swap?). I'll jump up and be the Guinea pig for the heat coating test. Just gotta know.

[SergntMac]

As for "cool cans" I haven't seen one on an injected engine,and i spend a lot of time at drag strips. Truth is cold fuel is harder to atomize so it's kind of counter productive. What it did back in the day was cool the carburator which helped cool the intake air. BTW raising the pressure of the fuel to the 40 or so psi required to run a NA engine, not to mention the 80+psi the blown guys may run adds a lot of heat to the fuel.
Well, I'm a blown guy, and you're making my point without knowing it.

Fuel under pressure is already ambient hot in the tank, and it gets warmer due to it's pressurized path forward, yes? Seems logical to me that if we add a "cool can" to this path, and lower temps after fuel has passed through 80 percent of it's heat building pressurization, we're better off. I don't mean freezing it, just lower temps to the point where it enhances the combustion process. Just cool enough where atomization is closer to perfect, or, ideal, despite it's rise in temp from pressurization. Can't be any less valuable than this theory of coating the intake, every little bit helps.

I'm suggesting that adding a cool can will "normalize" fuel temps towards an ideal combustion temp, and enhance it's atomization at the injector...IMHO.

[CRUZTAKER]

I've never seen it, but I'm sure some of you a few years older than I may have.

My father once spoke of some crazy things they did back in the day such as routing and wrapping a/c cooling coils (perhaps freon) around the fuel line somehow. I also remember speak of routing the a/c blower thru the air box / intake and turning the a/c off just before a run.

Sound crazy? My dad was a little crazy. But he did race cars in the 60's.

[FordNut]

Here's a link to fuel coolers (supposedly for both carb and f.i. applications) and cool cans (yes they still make them) found at Summit. Anybody want to try one of these?

http://store.summitracing.com/default.asp?target=search.asp&type=bykeyword&searchtype=both&part=cooler+fuel&x=10&y=9

[martyo]

Anybody want to try one of these?
If you're buyin', I'm flyin' !!

[CRUZTAKER]

....you buy I'll fly:P

[rumble]

So you're the one with the other spare intake. Who is next in line? I need to get in line for one of these, either this one or Tom's (anybody else with a Trilogy want to start a chain or just swap?). I'll jump up and be the Guinea pig for the heat coating test. Just gotta know.

I don't know of a "chain" for this like we did with the Valve Covers. Logan
is technically the owner of my old one and as soon as I get it swapped out
I'll get it back to him. The only problem I have run into is that I want to do
this myself but am absolutely jammed up in remodeling and moving into a new
home and traveling for business.

c'est la vie

[SergntMac]

I don't know of a "chain" for this like we did with the Valve Covers. Logan
is technically the owner of my old one and as soon as I get it swapped out
I'll get it back to him. The only problem I have run into is that I want to do
this myself but am absolutely jammed up in remodeling and moving into a new
home and traveling for business. c'est la vie
I admire the energy to explore this mod more. I expect the gains to be minimal for the time and money invested, but at some point, this may prove to be another "tricks and tips" mod for the fine tuner. It has possibilities.

Before anyone sets out on this exploration, look into Dennis Reinhart's cooling kit for our InTech 4V engine. It's seems a minor mod, but it addresses a real problem that is costing us all HP and TQ. The water jackets around the 7-8 cylinders (last two on the driver's side) are incomplete. Coolant gets there, but doesn't circulate out well, and these cylinders typically run 40-50 degrees hotter than the rest of the engine.

I'm speculating now, it's my guess that this is why this engine got only one knock sensor when it was drilled for two. The knock sensor is planted between cylinders 6 and 7, as close as it can get to the problem area, and when detonation is detected at the point it's most likely to occur, the ECM pulls spark and timing to protect the engine. Solve this problem first before exploring the intake heat question, and you'll get much better results from that.

Call Dennis for pricing, it's a hand full of Cobra parts and a must do safety mod that should be completed before exploring performance mods. At least you'll get better results..IMHO.

[cyclone03]

Well, I'm a blown guy, and you're making my point without knowing it.

Fuel under pressure is already ambient hot in the tank, and it gets warmer due to it's pressurized path forward, yes? Seems logical to me that if we add a "cool can" to this path, and lower temps after fuel has passed through 80 percent of it's heat building pressurization, we're better off. I don't mean freezing it, just lower temps to the point where it enhances the combustion process. Just cool enough where atomization is closer to perfect, or, ideal, despite it's rise in temp from pressurization. Can't be any less valuable than this theory of coating the intake, every little bit helps.

I'm suggesting that adding a cool can will "normalize" fuel temps towards an ideal combustion temp, and enhance it's atomization at the injector...IMHO.


HUM........
Good point Mac.
I wonder being fuel atomizes easier at higher temps what the optimum temp is?

The other thing to think about is,do we want another 10feet of pressurized fuel flowing around the car?Through a cooler and back.

[Cenzio]

Wow, there's lots of info on the web about this. Guess I should have checked there first. Based on further research, it seems that Silver and Heavy are steering me down the right path. That was the purpose of this thread anyway. Most sites I found recommend three different types of coatings for intake manifolds.

1) Inside surfaces of the manifold, use ceramic thermal barrier coating (like header coating). Keeps the heat in the metal from transferring to the air inside. Also coat the flange surfaces to block heat from the heads out of the metal of the intake manifold.
2) Outside surfaces of the manifold, use ceramic thermal dispersant coating. It's usually black in color and enhances the heat transfer from the metal to the outside air in the engine compartment. I still need to measure some temperatures, if the air temperature is higher than the upper intake temperature I don't see how the heat will go away from the manifold into the air.
3) Bottom surface of the manifold, normally the lifter valley in pushrod engines, use solid film lubricant coating. In addition to providing a thermal barrier, this keeps the hot oil from sticking to the bottom of the intake and heating the intake from the bottom side. I don't believe we have this surface to worry about, but I'll have to check further. Tom, how about some pics of the bottom of the lower intake?

All 3 of these coatings cure at around 300-350 degrees and withstand temperatures up to 1300 degrees.

Oh well, I was hoping to just do the upper, but since the thermal dispersant coating is black I'll have to do the lower too. Looks like a bear to get into some of those intake passages though. Todd, I hear you're next after Tom for the intake powdercoat roundy-round. I need to get in that line now so has anybody spoken up for "next"? What about Logan's? I thought he started another one going around.


FordNut

That is the question. If the outside engine compartment temp is higher than the incoming intake air charge, heat dispersion shouldn't much matter concerning barrier coatings. I'm strickly interested in ceramic barrier coating the upper intake cover on my 04MM with JetCoat Sterling. What is the final verdict regarding performance loss or gain or is it so much as negligable. I'm getting ready to do this to the upper intake only ( both outside and inside surfaces) I gotta say this was a great thread you started. I'm going to benifit regardless with the added Bling! I don't think I can deal w/ a black despersion coating. What are you latest thoughts? Please reply. Have you discovered any drastic performance detraction in your latest research that would preclude my intention. :bows:to you! P.S. An air charge would flow better over a smoother surface as would be created by the coating! As you so keenly brought up, forget atomization with fuel as this remains a downsteam distal event. :burnout: Respectfully, Cenzio Please Reply!

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FordNut

That is the question. If the outside engine compartment temp is higher than the incoming intake air charge, heat dispersion shouldn't much matter concerning barrier coatings. I'm strickly interested in ceramic barrier coating the upper intake cover on my 04MM with JetCoat Sterling. What is the final verdict regarding performance loss or gain or is it so much as negligable. I'm getting ready to do this to the upper intake only ( both outside and inside surfaces) I gotta say this was a great thread you started. I'm going to benifit regardless with the added Bling! I don't think I can deal w/ a black despersion coating. What are you latest thoughts? Please reply. Have you discovered any drastic performance detraction in your latest research that would preclude my intention. :bows:to you! P.S. An air charge would flow better over a smoother surface as would be created by the coating! As you so keenly brought up, forget atomization with fuel as this remains a downsteam distal event. :burnout: Respectfully, Cenzio Please Reply!

Don't know if this helps you at all but here is a thread we did last year on
engine temps with chrome. I would be interested to see how much barrier
coatings change these temps. If chrome didn't make a difference I question
whether the ceramic coating would, at least on a stock street MM motor.
http://www.mercurymarauder.net/forums/showthread.php?t=13054&page=1&pp=15&highlight=chrome

[FordNut]

I'll see soon. I just got my intake back from porting. Several of the people that spray thermal coatings suggested that the inside should probably not be done. Since the port/polish left the surfaces so smooth, I'm not getting the inside done. (mostly, anyway)

I'll pick the intake up from thermal coating shop tomorrow. All the outside parts are being done in black, the upper with dispersant, the sides and inside the "tunnel" of the lower with dispersant, the bottom of the lower with barrier, the inside of the EGR passage with barrier.

Here is what the intake looks like from porting, pictures with coating tomorrow, performance numbers in a couple of weeks...
http://www.mercurymarauder.net/forums/showthread.php?t=17584

[cutt]

who has done this i want one and what are the adverse affects?