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From: George Braly <gwbraly@gami.com>
To: "'lancair.list@olsusa.com'" <lancair.list@olsusa.com>
Subject: RE: engine dynamics- How much % of O2 ???
Date: Tue, 5 Feb 2002 16:10:47 -0600 
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          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
Bill,

How much O2 (as a percent) of the exhaust stream do you think there is in
the exhaust stream ?

	50F Rich of peak   xx %  ???
	50F Lean of peak   xx %  ???
	~ 20%?   ~ 10%  ~ 50%   ~ 5%  ~ 2%   ~ 1 %   ???
That is a starting point. 



Regardless of the answer to THAT  question,  consider that there has already
been a highly controlled experiment on this subject.  For about 400 million
engine operating hours,  Curtis Wright operated aircraft air cooled piston
engines 
at lean of peak mixture settings.  In fact, it was so critical that the
engines be operated lean of peak at high cruise power settings that CW would
sometimes refuse to honor the warranty if the airlines failed to keep
detailed records showing how the engines were operated on each flight.

If one reads through all of the old CW engine trouble shooting manuals,
there is never even a reference to any kind of problem with exhaust valves
due to running lean of peak.  In fact,  the primary problem they had was
when one of the two banks of cylinders ran rich of peak (due to a mechanical
linkage adjustment problem between the front and rear bank of jugs).

Operating at high power and rich of peak,  they routinely cooked off  9
cylinders in one trip to Paris.

There is simply no identified engineering  reason to believe that all of the
same thermodynamic and metallurgical issues that applied to those high
powered, steel barreled, aluminum headed, spark ignited, piston engines, do
not also apply to your high powered, steel barreled, aluminum headed, spark
ignited piston engine.

Is there?

Regards,  George Braly


-----Original Message-----
From: BILL HANNAHAN [mailto:wfhannahan@yahoo.com]
Sent: Sunday, February 03, 2002 2:55 AM
To: MAIL LANCAIR
Subject: engine dynamics


          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
I have enjoyed the discussion on engines, yet the
key point that prevents me from running lean of
peak has yet to be addressed head on.
<SNIP>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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