[Healeys] FW: Air Fuel Meters easy to find?>

[Bob Spidell]

FWIW, some aircraft use exhaust gas temperature (EGT) to assess mixture strength (most piston aircraft allow the mixture to be adjusted in flight).  The best (read: most expensive) measure EGT in all cylinders.

An EGT is a thermocouple and indicator that, well, measures the exhaust temperature, from which you can surmise the relative strength of the mixture.  EGT rises as you lean from full rich to "peak EGT," which roughly corresponds to stoichiometric.  Aircraft are typically operated at either 50-100degC "rich of peak" or 50degC "lean of peak."  The latter setting has become more acceptable--it was anathema until relatively recently--as the cost of avgas has gone north of $6/gallon (generally, it should only be used at power settings less than 75% of max continuous power available in the engine).


Bob

--
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Bob Spidell         San Jose, CA        bspidell at comcast.net
'67 Austin-Healey 3000             '56 Austin-Healey 100M
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 -------------- Original message ----------------------
From: "Dave Porter" <frogeye at porterscustom.com>
> Gary,
>  I assume you use AV-gas. Isn't there now an unleaded version of AVGAS? And
> if so, what are the down sides to switching?
> Dave
> 
> frogeye at porterscustom.com
>  
> Porter Customs
> Albuquerque, NM USA 87107
> 505-352-1378
> 1954 BN2
> Porter Custom Bicycles
> www.britishcarforum.com/portercustoms.html
> http://picasaweb.google.com/porterscustombicycles/PorterCustomBicyclesStuff