westf27
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| posted on 31/8/05 at 06:24 PM |
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stainless headers glowing
had trouble with headers glowing red recently.made various adjustments and problem went.Any ideas what normally causes this so i can avoid a
repeat,you would think the pistons would melt.I should add this occuring whilst idling and the engine was normal temp.
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stevebubs
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| posted on 31/8/05 at 06:28 PM |
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ignition too far advanced is one cause...
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rusty nuts
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| posted on 31/8/05 at 06:42 PM |
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As already suggested Ignition timing and also a weak mixture could be contributing to it . Your recent post on cam timing anything to do with it?
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westf27
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| posted on 31/8/05 at 06:46 PM |
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no,but i think the strongest possibility was very rich idle due to needle valve trouble and facet pump.Binned the pump and changed the needle
valves.
anyone else agree with very rich idle( fuel damp plugs)
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MikeR
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| posted on 31/8/05 at 06:49 PM |
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wouldn't really weak mixture be a cause as well ?
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Rob Lane
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| posted on 31/8/05 at 07:01 PM |
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Sounds like cam timing. Where the flame front is made to move out of head by the exhaust valves being opened earlier.
Not good for exhuast valves if left for long.
In extremis flame will actually almost leave the head into exhaust, causes it to glow almost white in a matter of seconds.
Usually occurs on Crossflows etc when a reground cam is fitted without checking timing. When a blank is ground it is not set by factory
'peg' timing, so needs either a vernier drive wheel or offset peg.
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mookaloid
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| posted on 31/8/05 at 07:03 PM |
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Actually it is ignition being too retarded which causes this.
The mixture is still burning when the exhaust valves are opening so combustion carries on into the exhaust.
If it is making the manifold glow just think how it must be affecting the exhaust valves!!
Cheers
Mark
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Rob Lane
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| posted on 31/8/05 at 07:18 PM |
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That's one reason but not if ignition timing is set to correct value but cam timing is out. i.e. assume TDC is firing point (its not) then
piston is correct, spark is correct but exhaust valve is opening due to incorrect cam timing.
Common on crossflow etc as crank timing marks are used to enter the dizzy but cam is in wrong position.
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MikeRJ
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| posted on 31/8/05 at 09:13 PM |
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quote:
Originally posted by westf27
no,but i think the strongest possibility was very rich idle due to needle valve trouble and facet pump.Binned the pump and changed the needle
valves.
anyone else agree with very rich idle( fuel damp plugs)
Rich mixtures make the engine run cooler, not hotter. Weak mixture or igntion timing would be the first two things I would check, but I've not
heard of headers glowing at idle before!
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Liam
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| posted on 31/8/05 at 10:06 PM |
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Could cheap thin material be a contributer too?
Liam
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NS Dev
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| posted on 1/9/05 at 08:07 AM |
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sidetrack to the post (as the question has been answered anyway) but think of the poor exhaust valves on a turbo engine with anti-lag then!!!!!!!!!
It is not at all uncommon to see exhaust manifolds glowing under load. Most cars with tubular manifolds do if you look while they are on the rolling
road. On the mild steel exhaust manifold on my XE engine on the rolling road it was glowing a lovely cherry red under full load at 7500 rpm, and the
timing and mixture were certainly spot on on that! 
take a look at this film, I think he has the engine set up pretty well
Turbo + Supercharger = fun - click here
[Edited on 1/9/05 by NS Dev]
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Dave J
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| posted on 1/9/05 at 11:49 AM |
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Hells teeth!!! now that is impressive.....brave cameraman too!!
Dave
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MikeRJ
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| posted on 1/9/05 at 05:08 PM |
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quote:
Originally posted by NS Dev
It is not at all uncommon to see exhaust manifolds glowing under load.
Absolutely agree, but when was the last time you saw them glowing with the engine just idling (I don't mean after a full power run)?
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NS Dev
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| posted on 1/9/05 at 05:20 PM |
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hmmm, never!
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