Ceramic Coating not the best option?

I originally planned on coating my piston crowns, combustion chambers and valve faces with Swain's Gold ceramic coating. After reading Maximum Boost by Corky Bell I am questioning this option.
He talks alot about detonation and thinks that these ceramic coatings just add to the possiblity of detonating under boost because they keep heat out of pistons(which I agree is good) but make it stay in the combustion chamber, making temps greater, and closer to detonating.

Who agree's with this and who doesn't? I am thinking that I will be fine with a good intercooler to keep intake temps down, but I don't wanna make a mistake.
Any suggestions or experiences will help.

Hunter

Originally posted by teamsleep13
I originally planned on coating my piston crowns, combustion chambers and valve faces with Swain's Gold ceramic coating. After reading Maximum Boost by Corky Bell I am questioning this option.
He talks alot about detonation and thinks that these ceramic coatings just add to the possiblity of detonating under boost because they keep heat out of pistons(which I agree is good) but make it stay in the combustion chamber, making temps greater, and closer to detonating.

Who agree's with this and who doesn't? I am thinking that I will be fine with a good intercooler to keep intake temps down, but I don't wanna make a mistake.
Any suggestions or experiences will help.

Hunter

Detonation and preignition are differerent phenomenon, but are closely related. Preignition is defined as the ignition of the fuel-air mixture before the regular ignition spark from the spark plug. Detonation occurs when excessive heat and pressure in the combustion chamber cause the air/fuel mixture to autoignite. This produces multiple flame fronts within the combustion chamber. Both can lead to engine damage. By coating the piston crown and valve faces, these surfaces are kept cooler and more heat stays in the combustion chamber during combustion. This heat is what drives the piston downward, that's why thermal barrier coatings can produce more power.

But this extra heat is all within the combustion gasses, and when the exhaust vlave opens nearly all of it exits into the exhaust port and out into the headers. When the fresh intake charge is introduced, it doesn't "see" any of this heat. In fact, since the intake valve is cooler, the intake charge temp is lowered and it picks up less heat from the other surfaces as well.

So, I disagree and think that coatings are a good idea. So good that I use them.

Rich Krause

My engine has no coatings on the piston tops, and that sounds pretty much like the reason I was given for not coating them in an engine with a huge dose of nitrous. I wasn't able to discuss in detail, because at that particular time in my life I was working in Italy and my engine was being assembled in PA, and communications were "limited".

They did propose an alternative to a ceramic coating, but they swore me to secrecy before they told me what they recommended.... but it was not a coating.

I really feel ignorant in this area, because if you listen to Swain or Ray Bohacz on coatings, there seems to be absolutely nothing negative about them.

And the other thing is that the aluminum alloys used in pistons melt at something like 1300-1400F. It's nice when you don't exceed this temp! Actually, though it's been a long time since I studied materials, I think you don't even want to get too close to the melting point of metals under as much stress as pistons. They start to deform and bad things will happen.

I'd be very interested to know of any real downside to ceramic coatings.

Rich Krause

why stop there? why not coat the piston walls and entire combustion chambers?

Is it because the ceramic coating is too soft for the walls? what about the combustion chambers?

I would be correct in saying that the less heat is lost out of the "bore", the less power is lost/most is made?

Ya I thought I was correct in my thinking that ceramic coatings on the pistons would help reduce detonation. I talked to Swain coatings for at least 35 mintues about this and I am convinced that they are good. Maybe not in nitrous applications, but in forced applications I think its a good option.
And yes I dont wanna melt my expensive JE pistons, or get they anywhere close....that would not be good.

Coating the walls...I think it would casue to much friction, and they would be scraped off. Combustions chambers would be coated, this is good to keep the heat in too.

But Injuneer, I would like to hear your engine builders reasoning for not using coatings in a nitrous engine. I wont be using nitrous but it would be interesting to see why they decided against this.

Hunter

I had my engine coated also - pistons, skirts, bearings, combustions chambers, and valves.

Everything else aside, the more heat energy you keep "trapped" in the gasses in the chamber the more torque you are going to make.

As Rich pointed out, I don't see any way that these coatings are going to lead to any detonation or pre-ignition conditions - if anything they should help either.

From my perspective the only real downside is expense - I tend to think they will/should be - but that depends on your priorities.


Chris

This might not be applicable as it comes from the turbine engine business but here goes anyway. The one short-coming with ceramic coatings is what happens when the coated part is rapidly heated and cooled. The metal expands and contracts much more than the ceramic. No matter how good the bond between the two there is the possibility of it breaking down and having the ceramic flake off. Maybe with a nitrous motor the massive pulse of nitrous and fuel could be doing too much cooling for the ceramic/aluminum bond to perform properly. Maybe?

Mahle claims their coated pistons are worth 10-15hp over other pistons:

“All pistons are surface treated with phosphate coating that aids in the break-in of pistons and pin. Grafal® surface coating treatment is applied as part of the machining process. Grafal®, a thin layer of small resin particles, reduces friction and provides increased lubrication allowing our components to withstand harsher engine conditions while reducing detonation. Bottom line:
Less Friction = More Horsepower.”

“MAHLE Racing pistons use a low tension ultra thin ring stack (1.1mm, 1.1mm, 3mm/.043", 043", 3mm) to reduce friction while still maintaining proper heat transfer. The ultra thin ring stack results in reduced friction and extra horsepower.”

“MAHLE is on the forefront of piston materials research. They have created the M124-S and MSP25-S alloys specifically to make lighter weight components with the strength and stability to withstand extreme pressures of racing. SB Chevy and 351W weights starting at 367 grams for the 4BBL class and even lighter in the 2BBL class!”


Now my question is….? Who believes this and is it the light weight, coating, thin rings or “all of the above”???

I frankly find it very hard to believe unless your spinning a motor to 9K or something.

I belive that the anti-friction coating on pistons skirts (which I plan to use) is a good idea. Reducing friction free's up horse power not matter what. Only some techniques may come into play at high rpms, but skirt coatings and reduced tension rings will free up horse power below 7000 rpms, I have seen dyno after dyno tests that show this.
Now the differences maybe 2 or 3 hp at 6500 rpms on a N/A motor, its much different on a FI motor. As loads go up, so do the frictional losses, so difference of 10 to even 20 hp maybe seen with coatings and low tension rings.
Now I am not saying that all motors should have skirt coatings and low tensions....that would be stupid. Unless you have a dedicaed drag racer low tension rings are out of the question to me because of more oil consumption. But if you are a racer, then its worth that extra oil for 10 hp.
Obviously lighter components reduces the power needed to accelerate them, so this will 'free up' horsepower, but I am not sure how much. It would be a pain in the ass to have to do dyno testing on this weight stuff, but in theory it seems right.

Bottom line, skirt coatings are worth it to me on my engine while I am still undecided about the thermal coating.
I am going to talk to Swain a bit more about the evenness of their applications, as I can see how unevenness can cause hot spots.
If anyone has any more information about using thermal coatings please share.

Hunter

hmmm- ok- stupid question time
isn't the same coating we see on headers right?

should i bother coating my combustion chambers and valves while i am putting it all together?

where do i get this done?
how much?
worth it?

I've looked into coatings alot.

First to answer Denny McLain,

The Mahle pistons are all about reducing friction and yes it's all of those things, the friction coating and the narrow rings. That's basically what a winning engine is, not one magical thing like a cam or 5cfm more flow, it's a bunch of little things that add up. The lower weight is going to help crank life and the high rpm/sec acceration and the additonal HP that it allows. If you have a Bonneville engine you don't need light parts really. A drag car or circle track car benefits greatly from them. Friction reduction comes in many forms, and coatings along with lower drag rings are some of them. Obviously the higher the RPM the more benefit you get, and on something like roller bearings for the cam, since it only turns at half speed, you need alot of RPM to see everything from them. I'd say that friction coatings are important, not as much as thermal ones. Yes a engine makes XXX amount of HP and loses some of it to friction. There are alot of things to reduce that, it's probably not the first place to go look for HP. I'd always spend the money on the heads first. If you're going to spend $10k on heads then you should probably have coatings. I would buy an electric water pump, underdrive the pulleys and get a electric fan before I put coatings in the engine.

Friction coatings are a different animal from the Thermal coatings.

The basic premise behind thermal coatings is that you marginally improve the thermal efficenentcy of the engine. By marginal I mean .2-.5 of a %. That's not very high, but it does help. The reason being that a engine is very thermally inefficient. Operating in the 35-37% range, where only that amount of the heat produced actually pushes down on the piston. While the other part escapes down the exhaust port. Now a .2-.5% total improvement is actually a .5-1.3% increase in thermal effiecency. So I have .5-1.3% more pushing down on the piston. That means that you can have that much of a TQ gain, and sometimes it's a higher percentage. So at 700 ft lbs we can find about 15 ft lbs, the higher the RPM the more HP you find. On a 450 ft lbs engine you can easily find 10 ft lbs. As I said above winning engines are not just one part but a combination of many little things that add up to that winning edge. Coatings are one of those.

One more benefit is that you can keep the total engine temps down, oil, coolant etc because you keep the heat in the chamber and exhaust. That means thinner weight oil, and lower temps to keep the air/fuel charge more dense and therefore make more power. The longer the engine runs the more they benefit you. Maybe a Pro Stock engine doens't get to much from them, but I would still run them. WJ has actually said that he doesn't like the fact of higher temps and on the edge compression ratios, and on a one trick pony like a Pro Stock engine I kind of see his point. On the other hand I'd rather run the same compression and have the coating help protect the piston and chamber from detonation. It's only got to live 7 sec at WOT so, hopefully it will.

Again, are these good for a street motor. Yes, are they the best use of your money. No. SPEND IT ON THE HEADS! Coatings are a last resort for HP, they are not high on the list. $1000 in coatings can go along way in head work, and 20cfm more (if the cylinder sees it) is worth more than $1000 in coatings.

One more way to look at it. It's about $500 for just TBC, to gain 2% more power that shoudl be about 2% of the engine budget, so at least a $25K engine is what you need to be looking at to realistically do this. Or there better be alot of prize money if you win.

Bret

Bret: for a street or street/strip SC or nitrous application the issue of lower piston crown temps eclipses the power gains. The commonest major failure for these applications relate to the pistons. Anything that lowers piston temps (I have heard from Swain that it can be up to 200F) in these motors is a blessing!

That's the reason I use them. Inspecting the crowns after 8,000miles revealed a completely intact coating, BTW. Swain was used. I fully expected to buy new pistons this year, but after close inspection I popped 'em back in (with new rings).

TBC coatings on the crowns are a good thing for a blower app regardless of any power gains, IMHO.

Rich Krause

Well its decided, my crowns, combustion chambers, valve faces, exhaust ports, and turbine housings are all being coated with Swain's Gold Thermal Coating.

I am really contimplating whether or not I should coat the headers. Only money will tell....

Hunter

Originally posted by teamsleep13
I am really contimplating whether or not I should coat the headers. Only money will tell....


Heck, that would have been the first thing I coated. If nothing else to keep them from rusting and looking bad. That is unless they're stainless, but if the extra $200 or so for coating is bothering you then I doubt they are...

IMO skip the exhaust ports and put the money towards coating the headers.

how thick is this coating? significant enough to effect compression?

i'm thinking of coating my CC's

Rich,

Yeah we think in different worlds most of the time, but you are right with any blower, turbo, N2O or Nitro setup the Gold Coat is going to protect the pistons more than about anything. 200F is pretty good, it sure beats oil sprayers pointed at the bottom of the pistons, that just seems to add windage to the situation.

Soma07, teamsleep,

The header coating from swain is not like Jet Hot. It's actually a heat barrier more like header wrap than the semi-protectant that Jet-Hot does. Keeping un hood temps down is about as important as anything in the heat related world.

BTW if I was doing heads, you might as well do the exhaust ports too just to keep the head temps down. It's probably one of the bigger areas of heat transfer in the engine. That and the combustion chamber.

Trey,

The coating is very thin, depending upon the company. Callico states that their friction coatings are .0002-.001 thick depending upon the application. That's important for things like clearances, but it's not going to effect compression ratio.

Seriously, if you are NA, spend the coating $ on more head and valvetrain work first. This stuff is not the magic bullet, but it does help. If you don't have some extensively ported AFR's for your 383 LT1 then you probably will find much more power there and in your intake manifold than on coatings. In fact $400 on making that intake better is worth more than the coatings ever will be.

That's all I have.

Bret

The point is... imagine a cooler running engine for the street??? Isn't that a great thing??? cooler engine bay temps??? that is amazing too... That will all help everything.. imagine your car cools down faster??? etc.. that is the advantage...

I have jet hots black coating... Is it that big of a difference between the thermal barrier coating that swain uses????

Originally posted by The Highlander
The point is... imagine a cooler running engine for the street??? Isn't that a great thing??? cooler engine bay temps??? that is amazing too... That will all help everything.. imagine your car cools down faster??? etc.. that is the advantage...

I have jet hots black coating... Is it that big of a difference between the thermal barrier coating that swain uses????

I think the point of the coating is to keep the heat enegry (what moves your piston) inside the cylinder and to keep it from radiating out. Ceramic conducts less heat than aluminum. The cooler coolant is just a positive byproduct.

Is that your question? was there a question? was it a statement:confused:

ohh yeah, keeps stuff safe in FI applications too (thats why Rich coated his pistons)

Originally posted by treyZ28
I think the point of the coating is to keep the heat enegry (what moves your piston) inside the cylinder and to keep it from radiating out. Ceramic conducts less heat than aluminum. The cooler coolant is just a positive byproduct.

Is that your question? was there a question? was it a statement:confused:

ohh yeah, keeps stuff safe in FI applications too (thats why Rich coated his pistons)

It was a statement.. what is the difference in a 600rwhp car 15 horses??? not that much to be felt or noticed at the track...

But... keeping stuff safe so you can go harder than 15 horses is an advantage... The coating itself will give you 15-20 HP, but it will let you add more boost or more timing...

Originally posted by The Highlander
The coating itself will give you 15-20 HP, but it will let you add more boost or more timing...

or less fuel.

Lean is mean, and some things that I have seen lately put real lean in a scary category and they make some amazing power.

We're talking 17:1-14:1 @ WOT.

Bret

"Lean is mean"

Yeah... for some engines it is but if your racing an old AMC motor with 30 year old combustion chamber designs it may not like it.;)
Every engine's different.... some like to be a bit lean and some go a little faster when slightly fat. Tune to find out what yours likes.:)

-Mindgame

Even if mine liked it at 13:1 (which it does) I rather loose 15HP but I tune it at 12.5:1 or less and have the security that it will not ping when racing hard... I better loose a race rather than break my engine :)

Actually I bet a 10.6@136mph rx7 from 40 till 150... So whatya think???

I think that's great High.:thumb:

And I agree... a safety margin is always nice. I would rather leave the leanburn engine stuff to those environmentalist type engineers.;)

-Mindgame

I'm not suggesting that someone run it that lean, you really need to know your conditions and test, test, test it on the dyno.

I only mention this because when I saw the BSFC being in the low .300 range I was REALLY suprised, but then seeing the corresponding A/F I was less. Basically that lean is only going to happen on something very fine tuned.

Bret

Exactly.. but how do they measure the BSFC on the dyno???

I have never seen it done...

Anyways.. by calcs.. mine is at 0.65 or something...

and I get little gas mileage.. 15mpg on highway.. 13 on town.. DAMN!!! is it the cam??

Anyways... Can you remove the pistons without taking the engine out??? I want to ceramic coat them...

Brake Specific Fuel Consumption is based on the lbs of fuel per hour per HP, so to have a .65 means that you are really rich and not making alot of HP for the amount of fuel consumed.

BTW no real good way to take the pistons out and put them back in while the engine is still in a street car

Originally posted by The Highlander
Exactly.. but how do they measure the BSFC on the dyno???

I have never seen it done...



Try this link: See page 2.

http://www.superflow.com/acrobat/sf901.pdf




Turbine fuel flow meters are used. Fuel flow (lbs/hr) can be displayed, and BSFC is calculated by the software.

Same for air flow.

BTW no real good way to take the pistons out and put them back in while the engine is still in a street car

why not????

Another thing.. Ceramic Coating is not cheap.. its very expensive..

336 for the 8 pistons.. GC and skirts its not cheap at all..

334 for the heads... damn... hard for an university student .. jejeje

Bret

That was a very articulate reply. Honestly one of the better and more informative posts I’ve seen in a while. Good job and thank you for the perspective.

Now that I’ve got your ear……… How about “thin” rings for street driving?

In retrospect, I had ring problems in a relatively recent 398ci motor and feel the engine builder may have been in error by trying to find that extra ½% or so by using a more race suited ring. Or.. maybe the ring was just too thin for the piston (lightweight J&E’s). Whatever?? Just guessing, but for sure something was amiss.

When the engine was torn down after 4k miles, the rings looked like they had 100k miles on them and the motor would not produce the kind of power on the top end it should have indicating ring flutter.

What I’m really trying to figure out: Just a botched job and is it worth trying to run the thinner rings on the street?

There is something to be said about things that you know work vs being too close to the edge. As you know….. it’s a fine edge between hero and zero. But then again there something about being a hero.

What rings are the best compromise?

Dumb question...

Where's the friction? I thought it was just the rings that came in contact with the cylinder walls...

Ya most of the friction comes from ring drag. The pistons also add a significant amount of friction the cylinder walls. Also, bearings add friction.

Most friction coatings are molybednum based, the stuff that the popular 'moly' rings use. This reduces friction between the rings and the cylinder walls. To further reduce this friction, coating the piston skirts with this anit-friction coating will help.

Reducing ring thickness and oil ring tension to reduce friciton, should only be used by serious drag racers. And reducing ring thickness is a risky thing when using large amount of nitrous or in forced induction apps. Using low tension oil rings on the street will reduce friction, yes, but unless you are running either a dry sump system or vacum pump to help reduce oil blowby into the combustion chamber. Most street cars dont have these so I wouldn't put low tension oil rings on them, but to each his own. If you can handle some extra oil cunsumpsion then go for.

But try the thing rings on the street, if they work, then sweet.
Always try new things.

Hunter

Thanks. I always thought the rings kept the piston itself from making contact with the cylinder wall.

I don't do a blown motor without the barrier coating anymore. Once the benefits were explained to me by Scott at SD Concept Engineering and how much boost and compression I could run SAFELY with the coatings I gave it a try. 9.7:1 (Scott wanted me to run 10:1 but I chickened out!) EFI 468 big block, 14 psi of boost on 91 octane with no intercooler, no detonation even at 28 degrees of timing (most I tried). No way that would have lived without the coatings. To me $300 is not expensive for the enormous safety factor it gives. And not having to take all the timing out of the motor makes a big difference in power.

I've used Swain and Techline, both have worked flawlessly.

Jody

I was curious about this.. I sent my intake manifold to be coated top and bottom but after reading this article should I coat it with a thermal barrier on the top?

http://www.techlinecoatings.com/art...old_Article.htm

It says that you want a thermal barrier on the bottom and a thermal dispersant on the top for the air to cool down faster the intake manifold..

WHat you guys think?

You only want to use a barrier on the bottom b/c any heat that does get into the intake you want to pull out. The ambient temp under the hood is not enough to put a barrier on. The dispersant will pull the heat alot better than trying to block it. Plus any heat that would get in the intake couldn't get out. Another advantage to Techline coatings is that the thermal barrier has oil shedding properties as well. So any hot oil from the valley will not stick to the bottom and absorb the heat. In addition to what everyone else has said about coating the entire engine is well worth the $. The differences in the tune that you can run can result in big gains. And the friction that is cut down by coating the bearings as well as the CYC walls is awesome. The differnce you can feel just by touch is very noticable.

Originally posted by 1FastRedZ
You only want to use a barrier on the bottom b/c any heat that does get into the intake you want to pull out. The ambient temp under the hood is not enough to put a barrier on. The dispersant will pull the heat alot better than trying to block it. Plus any heat that would get in the intake couldn't get out. Another advantage to Techline coatings is that the thermal barrier has oil shedding properties as well. So any hot oil from the valley will not stick to the bottom and absorb the heat. In addition to what everyone else has said about coating the entire engine is well worth the $. The differences in the tune that you can run can result in big gains. And the friction that is cut down by coating the bearings as well as the CYC walls is awesome. The differnce you can feel just by touch is very noticable.

Swain offers two different coatings, one for the bottom of the intake (a thermal barrier) and one for the top which is an emitter.

"Intake Manifolds. Black body emitter on top and TBC on bottom maintains the mixture's temperature at the optimum for the desired performance characteristics."

http://www.swaintech.com/autolc.html

Rich Krause

Originally posted by Denny McLain
Bret

That was a very articulate reply. Honestly one of the better and more informative posts I’ve seen in a while. Good job and thank you for the perspective.

Now that I’ve got your ear……… How about “thin” rings for street driving?

In retrospect, I had ring problems in a relatively recent 398ci motor and feel the engine builder may have been in error by trying to find that extra ½% or so by using a more race suited ring. Or.. maybe the ring was just too thin for the piston (lightweight J&E’s). Whatever?? Just guessing, but for sure something was amiss.

When the engine was torn down after 4k miles, the rings looked like they had 100k miles on them and the motor would not produce the kind of power on the top end it should have indicating ring flutter.

What I’m really trying to figure out: Just a botched job and is it worth trying to run the thinner rings on the street?

There is something to be said about things that you know work vs being too close to the edge. As you know….. it’s a fine edge between hero and zero. But then again there something about being a hero.

What rings are the best compromise?

Sounds to me like the ring might be the wrong setup. Which JE lightweight piston? Was the motor running anything other than NA? Alot of this will have to do with it.

BTW a low tension setup can work on a street car BUT IT HAS TO BE DONE RIGHT! In total it can be worth 2-3% average power, which is alot to get a constant jump across the RPM range. That's almost like free cubes. There are a few ways to get crankcase pressure down in a street motor w/out a vaccum pump and w/o a dry sump. Cylinder wall finish needs to be good also. Only good way to check that is with the right equipment. Piston rings are very important in a engine. I work with companies that other people do not like (i.e. Total Seal) and I like what they do and how they work with people. Funny thing is there are alot of other really high end people that do too. Gaerte, Automotive Specialists (both big in the circle track ranks) Joe Gibbs, F1, WRC just to name a few others. Piston ring science is some interesting ****. How much should you play with it on a street car? On the sealing side alot. On the friction side? some. I would play more with the right oil rings, put the top ring in the right spot on the piston and make sure that the crankcase is not running extra high pressure.

Skirts also make alot of friction, not as much as the rings do. One more reason a long rod is good is because it adds piston stability, which means smaller shorter skirts. Piston design is also a little area to find some interesting things in.

One of the things that makes a $40K engine that vs a $6K engine is the little things. Custom pistons, custom rings, custom, custom, custom. Going into the details is a big thing in terms of the most bang you can get, but that costs mucho money.


Highlander, On a $6000+ intake manifold I would do the TBC and heat dispersing coating too. TBC on the bottom and HDC on the top. You wonder what a $6K+ manfiold consists off? About 120+hours of work. Just ask Wilson Manifolds. I don't know how much it's worth, but it can't hurt at that price level. Something like a air gap intake is probably going to do more for you. Keeping the engine running is also one way to keep it cool by constantly moving air thru the runners, that will easily take about 30+ degs out of the intake.

Bret

And all that heat going to the pistons...

Originally posted by The Highlander
And all that heat going to the pistons...

Nope. The heat emitted from the top of the manifold is heat lost from the intake charge, which is a good thing. The heat rejected by the TBC is prevented reaching the intake charge. It is retained in oil and to a letter extend in the block, both of which are preferable to the intake charge.

Rich Krause

I know the heat emmited from the top is heat lost from the intake...

My answered was to this:

Keeping the engine running is also one way to keep it cool by constantly moving air thru the runners, that will easily take about 30+ degs out of the intake.


That is heat that is being pulled from the manifold from the cold air INSIDE the manifold.. not outside. Where does that air go? outside??? If you shut down the car... and touch the manifold it'll be hotter.. now why is that? because there is no cold air blowing inside and removing the heat.. Now is taking and taking and taking heat from the heads and not being removed by the cold air...

Actually I have my SS hood for it to cool inside.

As far as the intake manifold is concerned, the TBC on the bottom will reflect the heat that would be picked up from the lifter valley. Unfortunately there is still a huge amount of heat conducted through the connections to the head.... (TBC the gaskets? :) ). Putting a TBC on the exterior of the intake would seem to keep that heat in the metal, and allow it to be picked up by the incoming air. It would also increase the time it takes for the intake to "cool down" between passes.

Originally posted by SStrokerAce
Highlander, On a $6000+ intake manifold I would do the TBC and heat dispersing coating too. TBC on the bottom and HDC on the top. You wonder what a $6K+ manfiold consists off? About 120+hours of work. Just ask Wilson Manifolds. I don't know how much it's worth, but it can't hurt at that price level. Something like a air gap intake is probably going to do more for you. Keeping the engine running is also one way to keep it cool by constantly moving air thru the runners, that will easily take about 30+ degs out of the intake.Interestingly enough, we decided to coat my pistons, but not my heads or my Hogan's intake with a ceramic heat barrier coating, although I asked about all three.

I can't remember Mark's justification for not doing it off the top of my head, but as far as the intake is concerned, the design separates the plenum from the lifter valley plate, allowing a significant amount of air to circulate beneath the plenum. It'll still heat soak with the car sitting stationary (like anything metal under the hood) but once the car is in motion, I don't believe that there will be much of an issue, especially since the sheet metal doesn't have much mass to retain heat. Sound reasonable?

http://home.gci.net/~jimlab/images/Intake/PC050027.jpg
http://home.gci.net/~jimlab/images/Intake/PC050028.jpg
http://home.gci.net/~jimlab/images/Intake/PC050048.jpg

If we'd gone with an LT-style intake, though, at the very least we would have coated the underside of the intake. I don't know how much a "heat shedding" coating on the exterior surfaces of the intake would have helped, but we probably would have tried that too. It's a damn shame that no one has successfully developed a composite intake for the LTx yet.

Air circulation is not going to cool the intake enough in a "air gap" design like a Super Vic, RPM Air Gap or a Sheetmetal. The sheetmetal will heat and cool faster than a cast peice. It's still aluminum so it's still going to heat soak.

Jim, you had a $25K+ motor, so TBC is the right thing to do there. I know the intake wasn't $6K but it was alot. My $ values are there because I feel that there is more $ per HP elsewhere in the system. Then you go to coatings.

Compostite is the answer to most of these questions. Just like the LS6 intake.

Injuneer was dead nuts right in his post.

Think about a spacer Fred, phenolic is going to work better than TBC coated gaskets. Or a insulating spacer there.

All of this is just minor extra stuff. It's most likely not going to be worth alot (effort and $ per HP is low) but it can't hurt. Engines are not one thing, or a magic cam, they are alot of little things. Which ones make it the most powerfull for the budget.

Bret

Originally posted by Injuneer
Unfortunately there is still a huge amount of heat conducted through the connections to the head.... (TBC the gaskets? :) ). Putting a TBC on the exterior of the intake would seem to keep that heat in the metal, and allow it to be picked up by the incoming air. It would also increase the time it takes for the intake to "cool down" between passes.

Another take: It might also increase the time it takes for the intake to externally heat up from exhaust header heat during a dyno test which consists of a warmup pull then three consecutive pulls which are averaged. Cool-down afterward isn't important here.

At the strip, if you can delay the warming from underhood heat during burnout and staging, that is the same condition. Ya' gotta win the first round before you need to worry about cooling between rounds.;)

My $.02

So you recommend doing a TBC on top too?

Originally posted by The Highlander
So you recommend doing a TBC on top too?

For the dyno test program I described, maybe top, bottom and inside too. In other words, prevent heat from getting into the aluminum intake manifold, and trap any that gets in there in the aluminum. This is close to a composite manifold as I can imagine getting an aluminum manifold.

Remember this is for a very specific test, especially if there is inadequate dyno room cooling/ventilation airflow. I'm not saying every engine, but if the last little bit counts....

As far as Injuneer said (tongue in cheek, maybe??), how about TBC on the manifold flange of the intake to help slow down the heat flow from the head ...and while we're at it, the manifold-facing head surface, too? In other words, completely TBC coat the intake manifold on all surfaces. Is that nutz? What's the down-side?

I'm still thinking a lot about this...haven't closed the mind yet.

THe supposed downside is that heat that gets on the manifold will not escape via the ceramic coating.. i was also thinking about powdercoating it black on top...

Is it a good idea?

Originally posted by The Highlander
THe supposed downside is that heat that gets on the manifold will not escape via the ceramic coating..

So what? Unless it traps enough heat to melt the manifold. ;)



i was also thinking about powdercoating it black on top...

Is it a good idea?

It depends, I guess: if it were black-body coating it would radiate heat from the manifold IF the ambient underhood temp was lower than the manifold temp, but wouldn't the coating absorb heat if the underhood temp was higher? That's what concerns me. Hey, underhood temps well above 150F (maybe approaching 200F) can happen.

Still thinking...

I know underhood temps can reach 200F... I have measured things at 190F with an infrared meter...

So.. Is it a wise idea to do a TBC on TOP?????

We do the same thing. I may have been misunderstood. We use a thermal barrier on the bottom and a dispersant on top. I can understand your question though. Why not just try to block it in the first place? Some heat is going to get in the intake. Through mateing surfaces, air temp, underhood temps, intake duct work temps, and other variables. If the top was coated with a barrier the heat that does get in the intake could not escape. The coating would be working against you. The dispersant will pull the heat out. Which if you think about it it is where it wants to go, up. Some people say it's not worth the $ unless you have a megabuck motor. Untrue. You spend $2000 on heads are you going to use a stock cam? Of course not. You have to have the whole (Head/Cam) package to see the benifits. You will see cooler temps with coating just the intake. Which will result in some gain. But if you do the whole motor you can see a big difference. Sure the coatings add to the thermal efficency of the motor. But it's these properties that allow you to change the tune on the motor to get these gains. i.e. A/F ratios and timing without the threat of detination.

Spoken like a true coating guy.


Not to bust your balls here but.........

$2000 heads.... $600 worth of coatings nets you a few HP. $600 more porting, better cam setup, more displacement etc.... will net you alot more HP. That's my point. Other things should be optimized first.

Coatings are worth it if and when you run into the $ limit or the rules limit. Spend the money in the right places first.

Bret

I agree the big ticket items should be done first. I never said otherwise. Gains of 40hp have been seen on a dyno. Due to changes in the tune allowed by the coatings. $600? Who is doing the coating?

Post some dyno charts, and not DR'ed up ones to back up that claim. 40hp on 1200hp is one thing on 350 it's another.

What are you doing with the tune on the coatings? Leaning it out more or throwing more timing at it? If you can't get the full timing in on a NA engine then you need more Octane or less compression. Coatings aren't going to help you there. Boost and blowers maybe, because they protect the piston tops from melting under the extra detonation.

A little context would be good to put in here in the "advance forum" Just a claim with nothing to back it up is not what most of us here look at.

Bret

i was kind of astounded at the 40hp number....

i was actually contimplating it while my heads were off

$500 for 40hp doesn't seem so bad- i paid more for headers and got less :D

Sstroker ace burst my bubble though:(

Fantastic, more people on the board flat out lying to sell their sh*t :).

The coating testing I've seen was applied to 2.2hp/cid NA roadrace small blocks on the dyno with everything with various coatings (thermal/friction). Nowhere near 40hp, more like 10-15 IIRC.

Unless you're pushing it, I wouldn't bother with most coatings. For longevity in a FI app, I'd consider it though :)

Originally posted by jimlab
http://home.gci.net/~jimlab/images/Intake/PC050027.jpg
http://home.gci.net/~jimlab/images/Intake/PC050028.jpg
http://home.gci.net/~jimlab/images/Intake/PC050048.jpg


Hum, I’m a bit confused here (and possibly off topic), but looking at those pics I see a lot of very sweet fabrication work, but I’m not sure that I see the point.

It looks like it’s for an LT1 (no coolant passages) running a distributor. The runner length and size appears to be roughly the same with a larger plenum volume. I don’t know that I see anything that would add up to a gain greater then if you cut open an LT1 and doctored it a bit, which I’m betting would have been much cheaper but wouldn’t have looked as good. Am I missing something?

Originally posted by WS6 TA
Hum, I’m a bit confused here (and possibly off topic), but looking at those pics I see a lot of very sweet fabrication work, but I’m not sure that I see the point.

It looks like it’s for an LT1 (no coolant passages) running a distributor. The runner length and size appears to be roughly the same with a larger plenum volume. I don’t know that I see anything that would add up to a gain greater then if you cut open an LT1 and doctored it a bit, which I’m betting would have been much cheaper but wouldn’t have looked as good. Am I missing something?Yeah... the ~340 cfm AFR 215 cc raised runner heads that intake was built to mate with. :)

http://home.gci.net/~jimlab/images/Engine/Completed/P1190044.jpg

The hole at the back is for my MSD digital CPC cam sync stub.

heh, that makes a little more sence...
:)

Originally posted by Ai
Fantastic, more people on the board flat out lying to sell their sh*t :).

The coating testing I've seen was applied to 2.2hp/cid NA roadrace small blocks on the dyno with everything with various coatings (thermal/friction). Nowhere near 40hp, more like 10-15 IIRC.

Unless you're pushing it, I wouldn't bother with most coatings. For longevity in a FI app, I'd consider it though :)

Im still wondering if coating Combustion chambers and exhaust ports w valves is a good idea to keep the coolant temp a little bit lower than usual... I am wondering if I will see this benefit. If it will lower the temp 15-20º I might do it.

Now that my heads are with you phil, I could sure take your advice ;)

Take care guys.

Lowering coolant temps will better be obtained through coating the radiator. Your motor should run at whatever the thermostat is labeled for. If your overheating with a thermostat then there are deeper issues. Between motors running no thermostat (so you have a constant) 15-20* drop in temps are easily gained. As for some numbers I have a few. On a Davidson Racing Engines Cheverolet 355 tested by John Erb, chief engineer for Keith Black Pistons, a 10hp increase was obtained with coating just the pistons. They were able to run 5 jet sizes smaller than uncoated. Before coating 1350 was the limit on egt's before parts failure. After coating egt's of 1450 were ran with no adverse effects. The coating allows for SMALLER jet sizes and LESS timing. The more efficient the motor the less timing is needed. On a partially coated engine, pistions and combustion chambers, an increase of 25hp was obtained. A ProStock app. (NHRA Legal 500ci) Reicheird Race Engine, made 1110hp, uncoated, and made a 1178 coated. A 68hp gain.

Why would you coat the radiatior? Unless you are limited by size it seems that a bigger more efficient radiator is in order.

The key to the coatings is that they KEEP the heat in the chamber to make the motor more thermally efficent. In cases like a SBC head where the center exhaust ports are very close keeping the heat out of areas like that will help with even cooling of the head and give you less hot spots in the chamber, therefore less chance of detonation.

Bret

Bret,

So do you recommend that I coat the heads although I have no coatings on the pistons?

Even if you go with a larger radiator you will still see benifits coating it with a thermal dispersant. It will cool more efficiently. I've seen motors with melted pistons and coated combustion chambers where the head came out great shape. It will definantly not hurt to coat what you can coat. Some people do it to push the edge and some do it for a little added insurance. There is no doubt it helps.

Im doing it for the cooling capabilities of thehead. If I can keep the head cooler im happier.

Originally posted by The Highlander
Im doing it for the cooling capabilities of thehead. If I can keep the head cooler im happier.

Might as well do the exhaust ports too since it's probably a SBC/LT1 head. Unless you want to run external cooling lines to the spot between the center exhuast ports.

Yes I was going to do CCs, exhaust ports and exhaust valves.. and face intake valves.

That and the piston top are the most effective places. Then I would say it would be to keep the heat out of the intake.

Should i coat the intake too??

My question: I have jet hots black coating on my headers.. should i send them the headers too for coating??

Thanks

You can coat the intake too, but there are other ways of keeping the heat out.

As for headers you want to keep the heat in them and not in the engine compartment. Jet Hot does a great job at that, while the only other option is thermal wrap, but you can't do both!

Bret

So i should not send the headers then... AS far as swaintech goes.. they say ceramic coating is crap from other people.. jeje...

Better for me this is becoming REALLY expensive...

I expect my heads to flow in the 300s range and then ceramic coat the chambers and ports.. should i coat the intake ports for flow?

I think I will leave the intake out of the coating if there is not a really noticeable difference.

I wouldn't bother with the intake ports.

I've seen tests where Jet Hot coating does a good job at keeping header temps down a good amount.

Bret

Thanks.. I will do then exhaust ports.. CCs valve faces and exhaust valves completely.

Would it be a good idea to port TBC where the intake sits? or would it prevent the gasket from mating or something similar? just to keep heat away from the intake or such.. jej..
Thanks