EGT

[Gregory R. Travis]

On Tue, 1 Apr 1997, Tom Cloud wrote:

> You have
> confirmed my warning with your statement about the life
> span of these type probes.  I had wondered if there were
> any made with a longer life -- guess not.

Well, I'm not sure their life span is really an issue.  I stated
that they typically lasted about 600-2000 hours in an aircraft (I realize
that's a ridiculous span).  That's about five to fifteen years of typical
use.  For example, I changed all of mine when I put a new engine in my
plane.  That was three years and 500 hours ago and none of the probes looks
like it's anywhere near the end of its life.

> the problem I see with EGT in an automotive app is we typically
> don't have the ability to dynamically adjust/control the mixture,
> and we're not operating at constant rpm/load as in a plane.

I agree, although I've seen Smokey Yunick (whatever you think of him)
with EGT probes on engines on the dyno.  I think the reaction rate of
the probes is slow enough to make them useless for street mixture
management.  Much better to use them to set up carbs/EFI on the dyno and
to develop A/F maps.

greg		greg at indiana.edu	http://gtravis.ucs.indiana.edu/