Posted for "colyncase on earthlink" <colyncase@earthlink.net>:

 Rick said,
  High EGT's do not necessarily relate to high CHTs - and can sometimes
  actually be inversely related.  Richer mixtures, can delay combustion
  timing, which can expose the EGT probe to more of the combustion heat.
  There is no max EGT (only a max TIT).
 
 
 They don't relate in an absolute way but they do tell you you are getting
closer
 to peak.  The work that George/APS did shows that there is a region
surrounding
 peak where the cylinder internal pressure is high because peak pressure
occurs
 nearer top dead center.   You can slide that peak pressure event further
after TDC
 by either getting richer of peak on the ROP side (extra fuel slows
combustion) or
 leaner of peak on the LOP side (extra air slows combustion).
 
 What I didn't know before taking the APS course is just how much extra fuel
it
 takes to get into the safe zone on the ROP side.   You want to be 180 dF rich
of
 peak if you are running 75%.    That is a lot more than most pilots will give
it.
 
 If you haven't taken the APS course I HIGHLY  recommend it.   I went in
thinking
 I would learn the fine points of LOP operation and came out realizing how
very
 easy it is to destroy your engine doing pretty much what we've all been
taught
 to do.   This is all backed up by hard data.   ...and now you can take it on
line cheap.
 Check out http://www.advancedpilot.com/ for only $395.
 
 Colyn
 
 -