O2 Volts

[Todd....!!]

FYI - I've SEEN my headers glow while idling at night....

I'm pretty SURE they glow while at WOT and any where inbetween....

How hot are headers when they begin to glow?  Is there some sorta
formula or somethin to tell us this, i've never heard of it, but I bet
there is a specific temp when a specific metal (Like Iron, FE) glows...

LATER!

Todd....!!

Bruce Plecan wrote:
> 
> I *added* heat with the lighter earlier, and no changes were noted.
> On the cars being used in really cold temps, the exhaust on several models
> the tubing would not crack spit. Meaning while over 210dF, was not really
> hot.
> On some vettes, the O2s are probably 4' away from the ports.  On a really
> cold day, at idle, with mechanics gloves (nomex type)(none operative cat)
> you can hold the exhaust back there.
>   If the temp was a major concern why is't there a true strategy to
> compensate for it?.
>   This when hot enough, is this the 800-900dC temp?.  When does an average
> engine reach an EGT of that?.
>   When speaking of a catalyst, fine, but without knowing what it is, and
> what it's properties are, is gets again rather mute, as I see it.
>   By the way, in all my testing I was using a strategy where by I know to
> some degree what the actual heater temperature is.  So I can duplicate this
> on car, and then see what is going on.  Without quessing.
>   While oems, are doing this O2 work as a emission law mandated issue, I'm
> just trying to figure out enough to do what I want to do.   Other issues
> don't matter, other than as a point of interest, or maybe concern for
> others.
> Grumpy
> 
> > >   The useful facts as I see them are:
> > >   In cold weather, a none heated O2 sensor can go open loop. due to the
> O2
> > > sensor being too cold.  A heated O2 develops enough heat so that it can
> > > "properly sense" the needed gases to operate.
> > >   The O2 sensor, as tested responds to HC rather than O2.
> > >   While you might be able to change things, or define other operating
> modes,
> > > I know that if I mount the sensor far enough away from the engine that
> being
> > > heated is neseccary, then I know what gases matter, and thus what the
> sensor
> > > is seeing.
> 
> > There are a couple of things I'd like to throw in the mix here.
> 
> > The heater on the heated sensor is a helper to get the sensor up to
> > temperature... it's probably still relying on hot exhaust gases to
> > be at working temperature... it may not be hot enough when testing with
> > room temperature gases.
> 
> > There is a catalyst on the electrodes which may well promote the
> > combustion of gaseous hydrocarbons with the O2 that diffuses thru
> > the sensor, hence the reaction to gaseous hydrocarbons.
> 
> > The sensor itself, when hot enough senses the relative concentrations
> > of O2.  This is not necessarily the O2 concentration in the exhaust
> > gases as measured by other means due to the catalytic action of the
> > sensor electrode...
> 
> > Orin.