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Old 02-08-2013, 10:14 AM   #1
t_l75
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Extremely hot headers??

Well ever since I rebuilt my engine and got my exhaust done, i have noticed the headers seem to be running way too hot. I used summit racing headers part no. SUM-G9003. Now I have hardly run the engine, so I understand that it should run hotter since everything is a lot more tight and hasnt broken in yet. But wouldnt that refer more to coolant temp than exhaust temp? Anyway, within the 30 minutes of total runtme i have on the engine, i have already burned out 2 spark plug wires. The wires are close, but they have at least 1/4" on each plug and I also have the heat sleeves over the ends of the wires. Something just doesnt seem right about that.

Im thinking it could be a few things:
1. Since I used a cheaper header, the actual metal thickness of the tubing is thinner thus it heats up a lot faster.
2. Since the header is only painted not ceramic coated, it runs hotter.

Now as far as I know, these are my options: please chime in with what you guys think would be the best option. I wanna do whatever is gonna get me the best result for the least amount of money. If buying a new set of ceramic coated headers is really the best way to go, then so be it but i would rather try to find a cheaper solution and make what i have work.

1. Use a exhaust wrap, ~$80 for 100 feet of 2" wide wrap
2. New set of ceramic headers ~$300
3. Get my headers ceramic coated ~$???

Now I have already tried multiple coats of 2000 degree primer and paint, and all it does is just begin to flake off within 30 seconds of the engine running.

Thank you again for all the help. If anyone has another option, please chime in
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Old 02-08-2013, 10:26 AM   #2
MIKE80
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When I bought my headers, before I installed them, I sent them to Jet-Hot and had them ceramic coated inside and out. I have no issues with them at all.
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Old 02-08-2013, 10:28 AM   #3
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Have you looked at the headers at night? Do they glow red?

Exhaust headers will typically overheat when the mixture is rich. There isn't enough oxygen to burn all the fuel so it ends up burning in the exhaust header. When I put the Whipple supercharger on my Yukon, the headers would glow orange/red. Just like if you heat up metal with a rose tip to bend it. Did that until the fuel map was cut down in the chip.

The head around the exhaust port will also glow if you run it that way long enough.

Check your fuel air mixture. My $.02
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Old 02-08-2013, 11:58 AM   #4
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The question is, how hot is the ENGINE running?
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Old 02-08-2013, 12:19 PM   #5
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Junkman2008, the engine was running at about a steady 215 degrees, while sitting in my garage with the dual electric fans on. I havent had a chance to drive the car yet, so i assume it will run a little cooler once i get more airflow into the radiator.

7Troadster, hmmm thats interesting. I have been having problems with the engine running and i havent tuned the air to fuel ratio yet, so that could be a factor. I just got the quadrajet rebuilt but the engine is backfiring really hard through the carb so i have torn off the valve covers and am gonna go through the valves. Is this shocking to happen on a brand new engine that has hardly any runtime?

MIKE80, how much did it cost fot yoou to get them coated? i am thinking of doing the header wrap, do you think that will be comprable?
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Old 02-08-2013, 12:26 PM   #6
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Let's see how hot it runs once you drive it. My headers use to run so hot that they would melt the spark plug wires and positive battery cable. Once I got a Griffin radiator and a 19" fan in that sucker, I eliminated that problem.
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Old 02-08-2013, 12:30 PM   #7
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Junkman2008, so you think that they will make a difference once i start driving it? what type of headers are you running? Im thinking of using the wrap just so I can lower the temperature under the hood. that way I dont constrict the airflow so much since im not running the cowl setup.
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Old 02-08-2013, 12:33 PM   #8
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I have Hooker headers. You need to run the car so that you can get a true idea of how hot the engine is running. Sitting still for a long period of time, I was melting all kinds of stuff. That was before the radiator change and electric fan.
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Old 02-08-2013, 12:36 PM   #9
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Junkman2008, okay i do plan on getting the car on the road, i just have to sort out the backfiring problem. I do have a champion 3 row aluminum radiator and the 2 12" electric fans. So im hoping once i get it on the road the headers will cool off. thank you for the help
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Old 02-08-2013, 12:39 PM   #10
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Check the firing order of your plug wires for the backfiring problem. I bet you got two of them crossed up. Also check your timing. Bad timing affects temperature too.
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Old 02-08-2013, 12:41 PM   #11
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Junkman2008, okay i do plan on getting the car on the road, i just have to sort out the backfiring problem. I do have a champion 3 row aluminum radiator and the 2 12" electric fans. So im hoping once i get it on the road the headers will cool off. thank you for the help
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Old 02-08-2013, 12:44 PM   #12
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Junkman2008, I have already double and triple checked every wire. and if you mean by checking top dead center for timing, i have done that too. I cant check it with a timing gun because the engine wont run long enough for me to see. Im thinking when the engine was built a valve was overtightened so its allowing the pressure back through the intake valve because the valve is staying open too late
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Old 02-08-2013, 03:03 PM   #13
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Air/fuel ratio. You have changed the air flow thru your engine and have not adjusted the fuel to compensate for it...
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Old 02-08-2013, 03:42 PM   #14
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Quote:
Originally Posted by t_l75 View Post
Junkman2008, I have already double and triple checked every wire. and if you mean by checking top dead center for timing, i have done that too. I cant check it with a timing gun because the engine wont run long enough for me to see. Im thinking when the engine was built a valve was overtightened so its allowing the pressure back through the intake valve because the valve is staying open too late
If you correct this issue it will run cooler , but any non-coated header will be blistering hot even on a properly tuned motor.
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Old 02-08-2013, 04:00 PM   #15
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Quote:
Originally Posted by iburke View Post
Air/fuel ratio. You have changed the air flow thru your engine and have not adjusted the fuel to compensate for it...
I gotta agree with Ivan here. Both a rich and a lean condition can cause the headers to get VERY hot very fast. if it is back fireing then your timing is most likely off also contributing to the heat. Make sure you have it on the compression stroke TDC and see where you are at. If you are running an hei you can get timing very close without engine running. Hook up the timing light, set the crank at the desired timing, turn dist. until timing light flashes. It will only flash once so pay close attention. You will probably need to advance and retard dist. several times to zero in on exactly when it will flash. BTW key must be in run position. Found this tip from several engine builders and didnt think it would work, but it does. That is how thay get the engine to fire off first try for break-in. Try it it works.
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