Glowing Headers

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dazedduster

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I Have A 73 Duster W/ 360 Stock W/ Headers. I Noticed The Other Morning The Headers Were Glowing Hot Back 2 On Both Sides. Timing Is Set Right And Carb Is Set Right (just Had Them Done By A Friend At His Shop. Any Body Have Any Ideas As This Does Not Seem Normal To Me.

Thanks
 
No its not normal.

I'll take a stab at it. Was the carb just rebuilt, jets changed, did he play with the bowl levels, timing reset? Its highly possible that you're running too lean due to changes that were made in timing or the carb. Are the headers new? They'll lean out your mixture too. The rule for all problems that pop up after playing with something is to: "Check out what you just diddled with!"
 
headers are new, carb has not been rebuilt, i was thinking it could be to lean but was not sure if that would cause it. i'll start there and keep going thanks for the help. i'll keep you posted.
 
Check the plugs in those cylinders....if they are bright white then you have a lean condition. What kind of manifold are you running dual or single plane? Could be a puddling/distribution problem. More than likely you'll need to up the jets in the carb.
 
You say that you noticed that the headers were glowing red in the morning, does that mean that they were red after it was started and warmed up at idle or after it was run on the highway or around town.

You state that the timing is "right" because your friend just set it. What did he set it to? Does it still have the vacuum advance and where is it receiving vacuum from? Did he set the timing with the vacuum advance hose removed?

Every time I've seen red hot headers from an idle speed warmup it's been caused by retarded timing.
 
Your back cylinders are running leaner than the front cylinders. Timing effects all the cylinders. The problem is not that you have glowing headers it is that you have some cylinders leaner or richer (depends on how you want to look at it) than the others. I have had more than one car after a highway speed run have the manifolds or headers glow at night. But the glow should be even and is OK as long as the motor is not too lean. Like mentioned earlier you most likely have a fuel distribution problem.

Chuck
 
you will probably find you need to up the jets on the secondaries of the carb.....I doubt it's a timing issue because of what 340 Mopar said.....it's a fuel issue to the back cylinders.
 
If you have a Holley carb with the pvc inlet in the back and being the primaries are farther away from the back cylinders than the front it could cause a leaner condition at the back cylinders.

Chuck
 
Ok, it was at idle for 15 min. or so, just changed plugs 2 days before. he set timing with a light that has timing degree display on back, its a carter 4 barrel (stock on my 340 i think) it has my 340 manifold on it (could it be laeking - just installed?)yes vacume advance. he was doing something with the vacume lines while timing it. i think it gets vaccume from the front of the carb. and last how would i fix a fuel distribution problem.
 
dazedduster said:
Ok, it was at idle for 15 min..... and last how would i fix a fuel distribution problem.
Click to expand...

If your exhaust was red after idling for 15 minutes, your primary jets are too small and/or your step up metering rods are too large (Original TQ). I'd go at least a size larger on your secondary jets also.

You need to fix this immediately because it will damage your engine. If your friends garage has a smog station, you could have him hook your car up and see how your mixture is. Does he have a dyno at his shop? Any acceleration under a lean condition will harm your engine in a short period of time.
 
dazedduster said:
he has a smog shop, no dyno. i'll fix asap, how can i tell what size jets i have to upgrade
Click to expand...

If its an original TQ all the jets and metering rods will have numbers stamped on them. You'll have to disassemble the carb so I'd recommend that you get a rebuilding kit with gaskets. Maybe someone here will be able to tell you what size jets came in the original carb.

Here's a really good site with a lot of information on TQ's and also parts:

http://thermoquads.com/
 
Like Ramcharger suggested. More advance. Happened to me when I started my fresh engine. Bumped it to 14 enitial and all the red disappeared.
 
GT340 said:
If your exhaust was red after idling for 15 minutes, your primary jets are too small and/or your step up metering rods are too large (Original TQ). I'd go at least a size larger on your secondary jets also.

You need to fix this immediately because it will damage your engine. If your friends garage has a smog station, you could have him hook your car up and see how your mixture is. Does he have a dyno at his shop? Any acceleration under a lean condition will harm your engine in a short period of time.
Click to expand...

Ain't no way that engine would run at idle lean enough to turn the headers red, plus it's not running on the primary jets, or metering rods at idle. Thats what the idle circuit is for. The timing is way retarded. Set the timing as lenweiler suggested with the vacuum advance line from the manifold disconnected and plugged. The reason the back tubes appeared red was because it was checked in the morning and it's always darker at the back of the engine compartment. The butterflies are probably open way too far as well, with the engine running off fuel pulled from the transfer slots, negating the effect of the idle mixture screws. Make sure the vacuum advance is connected to straight manifold vacuum which will increase advance at idle and at cruise and pull out timing when under full throttle, preventing detonation. Reconnect your vacuum line and adjust the idle mixture screws for highest vacuum at idle. Go for a test ride and listen for detonation. If it detonates, back your timing off two degrees at a time and go for another ride. Once you get this right, you can start mucking around with your carb, and that will be another post! Good luck and welcome to the world of high performance and "Learning to tune your engine 101". Your engine is no longer stock with the addition of headers and the sticker under the hood no longer applies, but I've always condsidered this the fun part because it gives me an excuse to pull some full throttle runs on a deserted frontage road! :thumbup:
 
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