Header are cherry red hot
Thread Starter
Instructor
Joined: Feb 2008
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From: Steger Il
Header are cherry red hot
Car is on dyno kooks headers are cherry red hot, tubes are glowing red car is only running at 3500 rpm, air and fuel ratios are perfect, timing is perfect, 02 sensor are ok, wide band is ok, can anyone tell me what may cause these headers run cherry red hot need help please right away.
Car also have a P1SC1 prochager on it vaccum is ok,and I have a meth kit I am running 50/50 meth water
Car also have a P1SC1 prochager on it vaccum is ok,and I have a meth kit I am running 50/50 meth water
Last edited by Norman Lane; Aug 20, 2009 at 03:33 PM. Reason: forgot to add other details
Pro
Joined: Mar 2007
Posts: 573
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From: CA
Touch it and see if its hot. 
Obviously kidding, most of the time headers get hot from lean conditions... are you sure your fueling is dead on?
*EDIT*
What kind of material are the headers made out of, are they coated? Brand? That would go a long way to help people determine your problem
Obviously kidding, most of the time headers get hot from lean conditions... are you sure your fueling is dead on?
*EDIT*
What kind of material are the headers made out of, are they coated? Brand? That would go a long way to help people determine your problem
Le Mans Master
Joined: Oct 2007
Posts: 6,149
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From: Greater Detroit Metro MI, when I'm not travelling.
Touch it and see if its hot.
Obviously kidding, most of the time headers get hot from lean conditions... are you sure your fueling is dead on?
*EDIT*
What kind of material are the headers made out of, are they coated? Brand? That would go a long way to help people determine your problem
Obviously kidding, most of the time headers get hot from lean conditions... are you sure your fueling is dead on?
*EDIT*
What kind of material are the headers made out of, are they coated? Brand? That would go a long way to help people determine your problem
Primary causes of excessive EGT are:
-Excessively retarded timing
-Running so rich as to create combustion in the exhaust.
Usually it's a combination of the two. And steel certainly won't glow at 450degrees, so something suspicious is going on...
Drifting
Joined: Apr 2008
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From: Lehigh Valley Pennsylvania
Le Mans Master<br><img src="/forums/images/ranks/5k-6k.gif" border="0">
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St. Jude Donor '08-'09
Leaner than stoich will cause a decrease in temp. Richer than stoich will cause a decrease in temp. Both of these would be measured in the combustion chamber. For excessive heat in the exhaust, a rich condition would have to exist such that the mixture was combusting in the exhaust. I don't know how a car's O2 sensor reacts when the mixture is combusting around it so I'm not sure how it would measure that condition.
Still, 450f isn't going to make steel red so something isn't adding up here.
Still, 450f isn't going to make steel red so something isn't adding up here.
Melting Slicks
Joined: Apr 2005
Posts: 3,418
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From: Chicagoland Area IL
As mentioned before plugged cats and cheep IR temperature gun will be considerably off with stainless steal. Most IR guns are set to read a emissivity around 0.9, stainless is considerably lower (can't remember off the top of my head).
Mike
Mike
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From: Feverish All Over
Might want to check your reading scale..
Melting Slicks
Joined: May 2008
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From: CT
Actually running lean will make the combustion chamber, but not necessarily the headers, hot.
Primary causes of excessive EGT are:
-Excessively retarded timing
-Running so rich as to create combustion in the exhaust.
Usually it's a combination of the two. And steel certainly won't glow at 450degrees, so something suspicious is going on...
Primary causes of excessive EGT are:
-Excessively retarded timing
-Running so rich as to create combustion in the exhaust.
Usually it's a combination of the two. And steel certainly won't glow at 450degrees, so something suspicious is going on...
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Leaner than stoich will cause a decrease in temp. Richer than stoich will cause a decrease in temp. Both of these would be measured in the combustion chamber. For excessive heat in the exhaust, a rich condition would have to exist such that the mixture was combusting in the exhaust. I don't know how a car's O2 sensor reacts when the mixture is combusting around it so I'm not sure how it would measure that condition.
Still, 450f isn't going to make steel red so something isn't adding up here.
Still, 450f isn't going to make steel red so something isn't adding up here.
EGT wise running the engine leaner with full advance actually tends to drop EGT somewhat because the combustion is done by the time the exhaust valve open. Typically very rich mixtures will still be burning at exhaust valve opening and that's where you'll see the highest EGTs possible, specially when combined with retarded ignition timing. Your O2 sensor will think you are running leaner than you really are if combustion is still happening around it, since it will be detecting oxygen that has not yet been used up by the combustion.
Le Mans Master<br><img src="/forums/images/ranks/5k-6k.gif" border="0">
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St. Jude Donor '08-'09
Not true. Combustion chamber temperature increases with charge enleanment and hits a maximum around Lambda 1.1 - 1.2 depending on cylinder head design and mixing. Even though theoretically you would have "perfect" combustion at stoich, there is not enough time for proper air/fuel mixing so a leaner AFR promotes more complete combustion and thus higher burn temperatures. There is also less heat capacity in the intake air/fuel charge with leaner AFRs and that also contributes to the higher combustion temps.
EGT wise running the engine leaner with full advance actually tends to drop EGT somewhat because the combustion is done by the time the exhaust valve open. Typically very rich mixtures will still be burning at exhaust valve opening and that's where you'll see the highest EGTs possible, specially when combined with retarded ignition timing. Your O2 sensor will think you are running leaner than you really are if combustion is still happening around it, since it will be detecting oxygen that has not yet been used up by the combustion.
EGT wise running the engine leaner with full advance actually tends to drop EGT somewhat because the combustion is done by the time the exhaust valve open. Typically very rich mixtures will still be burning at exhaust valve opening and that's where you'll see the highest EGTs possible, specially when combined with retarded ignition timing. Your O2 sensor will think you are running leaner than you really are if combustion is still happening around it, since it will be detecting oxygen that has not yet been used up by the combustion.
Le Mans Master
Joined: Oct 2007
Posts: 6,149
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From: Greater Detroit Metro MI, when I'm not travelling.
Drifting
Joined: Jun 2008
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From: PNW
or maybe both of you should stop showing off what you think you know 
based on my personal experience, retarded timing will increase EGT, and so will a rich mixture.
Now on the other end, on two other vettes we had, one side was glowing red, we came to find out that it was a stuck rocker arm, go figure.
On the other vette, the MAP sensor was reading 100 kPa at idle and 100+ with some throttle on a NA vehicle, so you might want to start with the basics here, check using HPT if all the sensors are reading fine, MAP/MAF and O2's.
if all is check, duplicate the scenario and read your timing advance that should tell you alot.
a vaccum leak once cause a similar case in my car where the ECU was trying to pull the idle rpm down to its commanded idle rpm by retarding timing, so timing went to about -3 degrees and voila everytihng was glowing and the turbos were SPOOLING at idle.
based on my personal experience, retarded timing will increase EGT, and so will a rich mixture.
Now on the other end, on two other vettes we had, one side was glowing red, we came to find out that it was a stuck rocker arm, go figure.
On the other vette, the MAP sensor was reading 100 kPa at idle and 100+ with some throttle on a NA vehicle, so you might want to start with the basics here, check using HPT if all the sensors are reading fine, MAP/MAF and O2's.
if all is check, duplicate the scenario and read your timing advance that should tell you alot.
a vaccum leak once cause a similar case in my car where the ECU was trying to pull the idle rpm down to its commanded idle rpm by retarding timing, so timing went to about -3 degrees and voila everytihng was glowing and the turbos were SPOOLING at idle.
