I decided to do a little experiment today to measure the outside temperature of mild steel, coated mild steel and stainless steel headers under equal conditions. First I configured a "heat funnel" out of an old wheel trim ring, coat hangers, aluminum foil and a hose clamp to hold it to the collectors. Since it was nice out, I sat out in my driveway in the sun and made it. My neighbors, some of which I'm sure already think I'm certifiable, probably thought I was building one of those UFO hats to prevent aliens from scanning my brain or something. Then I attached all three sets of headers to a pole in the basement with the collectors downward, an equal distance from the floor. I attached my "funnel" to them, one at a time and put a kerosine heater under it, and took readings with a non contact thermometer at specified time intervals at the pipes, near the flange. I averaged the readings between the pipes on each set after 20 minutes because all had stabilized by then. The top of the heater which was just under the funnel was 635 degrees, BTW. After 20 minutes, the average for each type was: the uncoated mild steel were 198 degrees, the stainless steel were 144 degrees and the coated mild steel headers were 94.5 degrees. Now I know and you do too, and just think if I were to coat the stainless headers!

 

Tomorrow Im going to have to heat up the car and get temps on my coated headers. If I remember right the stock shorties ran about 600* F about 1" from the head.

 

Yes, I'd be curious to hear the result. I'd like to have done each type installed but I'm not that ambitious! It did verify what I had been led to believe. The coating makes a hell of a difference and the stainless falls somewhere in between. This also tells me the money spent coating the bottom of my intake, exhaust runners, combustion chambers and valves was well spent. The next time I build a new short block, the piston tops will get it too.

 

Something else you might want to test. After you turn off the heater, what is the temp after a given time period.

I know I can touch my headers in something like 15 minutes after the car has been turned off (coated inside and out). A friend of mine had un-coated headers and his were still warm after several hours!

 

Actually, I did that but since the headers weren't heated to real operating conditions, it didn't seem as relevant so I hadn't mentioned it. However, after 5 mins. of cooling, the stainless and the coated were about where they were after the first 5 mins. of heating. The plain steel were still quite a bit warmer than their first 5 mins. of heating.

 

Interesting experiment, makes me think, except in the end I am not sure I really understand what you are trying to prove and second if you proved it or not????????

Do we want the headers to be hotter or cooler????

Why????? Are we concerned about underhood temperatures or exhaust gas temperatures or ???

FWIW I am sure header temperatures on the outside is going to be primarily dependent on radiation cooling.......paint them flat black, or other surface coating to increase emissivity if you want them to be cool

BUT many more factors are going to come into play when they are installed in a given car.......conduction to/from heads, etc......

 

Just trying to show the relative difference in the three types. The cooler they stay, measured on the outer surface, the more of the heat is contained within promoting better scavenging AND reducing underhood temps. No down sides here. Painting could make a LITTLE difference but since no one's yet invented header paint that actually stays on for long.....

 

Hey Kid, checked my coated long tubes. Around 1 1/2" from the head the average was 300* motor running. Can someone with stainless and uncoated steel check theirs ??
Now for the can of worms we opened. Cylinder 5 was running 450* lean or what ?? Whats normal ?? Oh yea, my idle is rich this morning--trying a new chip.

 

OR stays on AT ALL...

 

Yes lean. Check out the injector for that cylinder ASAP. I would say normal is the average of the temperature of all the other tubes. You could install EFT sensors as well, but that would be overkill.

 

Pulled #3 and #5 plugs. 5 is lean compared to 3. It will be next weekend before I can get into it. I wish I had looked at these temps before I changed chips. The one I took out has much better BLM #s.

 

Corvette KID you are my new best friend!

now that somene here has cctully done a test to show how well he ceramic coating insulates these headers!

Ceramic coating is awesome... stainless and ceramic coated is the way to go although it is the most expensive... its the best!


I can ceramic coat any set of LTs for ony $188.
this includes tax, preping,coatig inside and out, and a 3 yr labor warranty!!!!!!
hopefully this will help feloow members save time, money and prolong the life of their engines/cars!!!!

thanks alot your friend
Sean
slimshaby@mindspring.com


AGIAN GREAT WORK!

 

well we want the headers to run cooler! thus keeping the hot exhaust inside the pipes so it goes out the back.....

you will benefit may ways from the ceramic coating.
under hood temps drop... as you know your intake and filter are under the hood.... thus making for cooler intake temps resulting in more power! also the more heat it kees in the less thet the spark plug wires, starter, asr and everything else under the hood see., helping them last longer.
with the heat staying inside of the headers and not being absorbed into them as much the hot exhaust gases travel out of the heads quicker...


your friend
Sean

 

Sounds like your in the know, I have EM long tubes coated by HP coatings. I would like to polish them up a little, is there something I can get at my local auto parts store?? or should I just order the polish off of HP's web site?
Thanks,
Denver

Thanks CorvetteKid, thats quite a temperature difference non-coated to coated. Good Job...

 

I can answer the uncoated steel question. Averaging around 475 that distance from the head.

 

Now we need stainless. Someone with EMs needs to jump in.

 

id say just order the polish off of there... you know how jet hotts offers the sterling coating that looks almost like chrome... well we do the same thing... not as much you can do now but that polish should help. we acctually now offer colored ceramic coatings.

I am guessing you go the regular grayish finish. take them off the car and take a soft soft cloth to them with thaat polish. should do wonders.
then let them sit outside for about 30 mins before reinstallation.

good luck your friend
Sean

i mena you can frist just try polishing them with a soft cloth might help...if that isnt enough order polish.

 

[QUOTE=redbullapril23]well we want the headers to run cooler! thus keeping the hot exhaust inside the pipes so it goes out the back.....
QUOTE]

I keep thinking about this and I am not sure if I agree with this or not.....

If the headers are running cool because the heat never gets to them, then this is what you guys are saying...

BUT if the headers are running cool because they are getting rid of the heat, then this means the exhaust gases are also running cooler than if the headers were really hot

????????????????????? I really think it is not as simple as you guys are saying?????

 

no it jsut means the heat is not mcoming through the headers!
the coating is insulating it. and the heat is going out of the back of the car... its that simple!