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.
ignition too far advanced is one cause...
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?
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)
wouldn't really weak mixture be a cause as well ?
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.
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
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.
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)
Could cheap thin material be a contributer too?
Liam
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]
Hells teeth!!! now that is impressive.....brave cameraman too!!
Dave
quote:
Originally posted by NS Dev
It is not at all uncommon to see exhaust manifolds glowing under load.
hmmm, never!