Glowing exhaust

[bjv]

The other night, when I lifted the hood on Plymouth 400, I noticed teh center tubes of the headers seemed to glow a bit. This is a stock intake but a Holley QJ replacement. Is it manifold design, carburetion adjustment? I can run the timing 10° to 12.5° BTC with no significant variation in color. You can't see the color change in daylight, just teh shadow of night.

Any thoughts? I have jet hot coated hooker headers on the car.

Bern

[fat bastard]

Could be either too lean or too rich, in most cases it is unburnt fuel. You can increase initial timing, tune in your idle circuits.

[dirty dan]

If this problem is only with one or two pipes.
I would look for an intake vacume leak.
If it were a leak around the carb you would have the same problem on more pipes then one or two.

[cuda66273]

Get one of those heat guns and shoot the tubes right by the flange the temps should run around 500-750*...you have a serious problem and you need to fix it fast.

At WOT throttle it should run around 1250 1300 on an EGT sensor and I believe that metal glows at around 1800...someone else will be able to confirm that.

[gsmopar]

Won't his header coating screw with the heat gun? Also, because you're using Jet Hot and it's a insulator I would call them first. If it's a long distance call for you let me know and I'll call them for you.

Later,

Greg

[Doug Wilson]

In the past.... (which is where most of my life is)... It has never been unusual for me to have glowing headers after a hard run on the street. I have had them glowing cherry red at the first bends. I thought they were supposed to??

[cuda66273]

I've seen it on sprint cars at night races...not my cars but others have had that problem.....usually last until lap 15 or so....

Allan's EGT reads about 1300-1400 and I don't think that's enough to make the glow even at night ..is it???

My headers have the coating and the temp gun reads about 500-700 at idle....whatever that means?

Doug, you coming to the Grove this weekend?

[ehostler]

I've seen too many B/RB headers glow at night. I wouldn't be concerned.

[cuda66273]

I guess my definition of a glowing header may be different...when I think of a header glowing I think more like you could read the Sunday paper by the light and heat a small office tower with a good enough fan

....there's the "Orange Glow" and there's the glowing RED...then white ...then the tow truck

[6pakman]

ok i will throw my two cents worth for what its worth. from what i know depending on how its glowing(ie brite, semi brite, barly showing) you are running lean. that is to much air. if it s not very brite i would not worry to much. but you can get rid of it by retarding you timing.or if you have a poor gasket between the header and head that can cause it. also thin metal headers can cause it.

[dirty dan]

Originally posted by cuda66273
I guess my definition of a glowing header may be different...when I think of a header glowing I think more like you could read the Sunday paper by the light and heat a small office tower with a good enough fan

....there's the "Orange Glow" and there's the glowing RED...then white ...then the tow truck

Yes I agree.
How much heat/glow are we dealing with.

[ehostler]

As the glow is only seen at nioght, I would say that it was an orange glow. You can normally see something that has a red glow, during daylight.

[bjv]

The pipes glow reddish - dull reddish at the first bend. Moving along the interstate seemed to keep th ecolor out of the pipes. I ran 65MPH for 15 miles and jumped out at the first stop to see the pipes color and there was nothing. Standing on idle the color began to appear. I have access to an infrared sensor reading and I'll try that ASAP. Last year I had a crack in the header at the first bend. The gas coming out was 825 but the pipe was about 700 or 750 - I don't remember exactly.

I actually seemed to dull the red color by advancing the timing. It was 6°BTDC and I've pushed it to 12°BTDC. The former had 8 inches of two pipes on each side glowing, now it is pretty much one pipe on each side.

Jet Hot felt I was too retarded in my timing.

The too lean might be something to follow up on. What would be the best guess for starting jets? This is a street car that tows a trailer, has an RV cam in it (more lift and just abit more duration than stock.) The Holley is a spread bore repalcement for the QJ . Economaster 2-270 is written on the box. I have no idea what the flow rate would be.

When I towed to Denver from Pennsylvania, the carb jets were changed to allow it to run on regular gas. I never changed it back. The discussion at the time was that I could run this set up without any trouble. The distributor was modified some also. I tin the vacuum advance was adjusted and a heavier spring put on the weight set. The car is still fast but doesn't have the strong surge as it comes into the cam's range.

I tried to track down the vac advance and the mech advance. I picked up the Mopar Engine book, but haven't gotten into it enough to work through this.

Bern