Glowing Header

[CWizard]

I checked the timing today on my 418W, which involved running the engine at various rpms for a few minutes. It ran at 1000 rpm for 5-6 minutes, then up to 2000 rpm for maybe 3-4 minutes. I got data at those points and was preparing to up the speed to 2500 rpm when I noticed the drivers side header was glowing red. Passenger side was not glowing. So I shut it down and grabbed my infrared thermometer. Driver's side header was 500F or higher (my gun only goes to 500) and passenger header was about 370F. Timing results: 22 degrees BTDC at 1000 rpm and 30 degrees at 2000. I stopped at 2000, so I don't have a current number for the total advance. Last time I checked it was about 34 degrees. So I don't think I have a retarded timing issue, unless the timing marks have suddenly gone bonkers (motor has 9000 miles on it). I've been fighting an overly rich idle mixture lately. Could a rich mixture explain the single hot header? Help!
Other info: Holley 4150 street HP on a Victor Jr intake. Hydraulic lifters were recently adjusted due to the addition of longer pushrods (valve geometry was wrong). No other changes, except the aforementioned idle mixture tinkering. Thanks.
Jerry

[Carnut427]

A lean mixture will cause a high exhaust temp; check for a missing plug in the intake or carb, possibly on the passenger side of the engine.
Just a hunch,

Dan

[trularin]

Have you cleaned your carb in the past few days?

Junk on one side of the fuel system will cause what Carnut427 is describing. A rip or tear in the air intake ( PCV or power brakes ) will also cause the problem, but you can usually hear that as a whistle.

[Bob In Ct]

This is not a timing issue or both sides would be glowing. Since you have a single plane manifold I would have to think that the drivers side is running leaner than the passenger side. I'm no carburator expert but it sounds like a jetting issue. At 2000 RPM I would not think it's related to idle mixture (but who knows).

Do you have a PCV connected to one side (driver's side) of the manifold? If so connect to the base of the carburator.

Bob

[J Persons]

I had this problem on a fuel injected small block Ford, using 42 lb/hr fuel injectors and a ProM mass flow meter. Contarary to what I have always been told, it was running extreamly rich on the drivers side, it was passing fuel into the exhaust where it would continue to burn, and light up the header. The cure was a mass air meter re cal. Usually, a glowing header can be caused by a lean condition, but in some cases, just the oppsite is true.

[1320]

Valves are to tight.....hopefully it hasnt killed the cam or lifters but hope wont fix it. The valves are hung open probably only when hot, causing the flame front to go out in the exhuast. Ofcourse its just a guess. Id check to see if the valves are closing all the way, easy to do.

Also 370 at idle is way way rich......glowing doesnt happen to well after 1600 or so.....most well tuned carbedengines idle around 550-650 and efi engine can idle as high as 750-850.....degrees meaasured 1 incj off the header flange on the top of the tube.

[CWizard]

1320 - Thanks for the info. Since I'm not real knowledgable about engines, I'm hoping you can explain a little more. By valves being too tight, do you mean the lash adjustment is too tight? And how do I check to see if the valves are closing? FYI, I have hydraulic roller lifters. Thanks again.
Jerry

[dsmith]

WATCH YOUR PAINT where the headers come through the body. While trying to get my car through emissions, I had the paint bubble.

Make sure you set up some fans, there is no air passing over the header tubes while you are running it stationary.

I also thought of putting a piece of sheetrock between the tubes and the body, but passed inspection before I had to do it.

good luck

smith

[Ron61]

I am not sure if it would show on your cut out in the body, but I took a piece of that chrome reflective tape and cut a thin strip the width of the fiberglass around my cut out and put it on the edge. Then I used thermotec insulation around them on the inside and have never had a paint problem. Of course my cut outs are different than most, so it may not work on yours.

Ron

[1320]

Originally Posted by CWizard

1320 - Thanks for the info. Since I'm not real knowledgable about engines, I'm hoping you can explain a little more. By valves being too tight, do you mean the lash adjustment is too tight? And how do I check to see if the valves are closing? FYI, I have hydraulic roller lifters. Thanks again.
Jerry

yes, if this basically hapened when you adjusted the valves, its possible to over tightened the valve lash , so that when the engine is running the oil in the hydraulic lifter (esspecially with lots of oil pressure) wont bleed out enough , and the valve doesnt close alll the way, causing the flame front from ignition to escape past the exh valve down the header. This also means that you have basically experienced zero lash, which could cause bent pushrods, broken roller lifters, etc...ussually the pushrod gives first. If this is the case, it sounds like it would just barely be on the edge so I say hopefully that everything is still ok. Ofcourse I could be entirely wrong.

[Thomas Gayer]

i had headers glowing one time and it was a stopped up exhaust system causing it. it was not on a race car but on a pos chevy 4 cylinder!
good luck

[Excaliber]

Thomas, so when you removed the potato from the tail pipe it was OK?