REFLECTOR: Cold Weather Flying

[John Dibble]

Had a good flight from MS to NY on Wednesday.  Stopped at DKX Knoxville 
for fuel.  That's a hard airport to find hidden in the hills.  A while 
back I reported that my temps were too low in cold weather and not 
enought cabin heat.  I decided to go after the source of the heat and 
reduce the engine cooling air, see pic.  I thought this would be over 
kill and I would have to trim it a bit, but it turns out that this just 
gets the engine temps to the bottom of the desired range (250-300F) with 
an OAT of 40 F.  At 30F CHTs are 240-245F.  Still, the oil temp ran at 
275F with the diverter flap fully deployed and that gave too much cabin 
heat.  During descent for landing, temps got very low and I had no cabin 
heat.  I would like to have a way to adjust engine cooling air from the 
cabin, so I can have max cooling for T/O and reduce cooing air at cruise 
and reduce it further for descent.  Has anyone done this?
When the OAT got down to 30F, I decided it would be a good idea to add 
some carb heat even though my manifold pressure was holding steady.  I 
did not see an expected increase in the carb temp gauge, but the MP did 
decrease by a few tenths indicating that the carb heat was working.  
Guess I need to work more on the the carb temp sensor placement.  I had 
moved it to the fitting where the manifold pressure line connects (carb 
outlet).  It seemed to be giving sensible readings at higher OATs, but 
not at 30 F where it counts. Looking forward to returning to warmer 
weather after the holidays.

John


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