Date: Wed, 2 Jan 2002 09:37:27 -0600
Reply-To: John Rodgers <jhrodgers@MINDSPRING.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jhrodgers@MINDSPRING.COM>
Subject: Re: B. Bobs day at the dyno and the importance of fuel airratio
update
Content-Type: text/plain; charset=us-ascii
Angus, thanks for your input on the question of EGT's for the Wasserboxer.
Since airplane drivers don't have the luxury of just parking an airplane by a
cloud when something goes wrong, and we as vanagon owners/drivers do have the
luxury of just pulling over and parking along side the road, to us the EGT
monitoring isn't near as essential. However, I think it would be very cool and
informative to be able to know what is going on temperature-wise with each
cylinder as we go through various power regimes when we are out driving. The
Boehler Digitool opened a world of knowledge and trouble shooting capacity for
vanagon owners. A good 4-cylinder EGT setup with Cylinder Head Temperature
(CHT) would be a definite Plus addition to the Digitool for monitoring and
trouble shooting our engines.
BTW, thanks for posting that site with the EGT Gages.
John Rodgers
88 GL Driver
Angus Gordon wrote:
> John,
> I believe there are enough differences between the aviation and
> automotive applications that EGT (exhaust gas temperature) is not a valid
> method of setting the mixture on a car engine. Remember that in an aircraft
> EGT is only a valid measurement for leaning purposes when compared to peak
> EGT for that specific power setting. That works fine in an aircraft, where
> you can set the power, lean to determine peak EGT in the leanest cylinder,
> then set the mixture relative to that cylinder's peak EGT. I don't know how
> you could accomplish that with the constantly changing power on the road.
>
> As to burning valves, many piston aircraft engines are designed to run at
> peak EGT or on the lean side of peak EGT in cruise. Exhaust gas temperature
> is used as a relative measurement again, not an absolute in these cases.
> The only limitations I know of in terms of specific EGT, are for
> turbocharged engines, where TIT (turbine inlet temperature) becomes a
> factor. Even in the waterboxer I think there'd have to be some other
> ingredient to burn a valve, i.e. incorrect valve lash, overheating etc.
>
> But, if someone wants the very best in EGT instrumentation (and CHT on the
> same gauge) here it is -
>
> http://www.insightavionics.com/pages/602.html
>
|