REFLECTOR: Re; NACA outlet

[Jerry Teitsma]

I have two oil coolers feeding into a collector box in the nose of my 173 FG 
(Franklin engine).  There is a flapper inside the collector box that diverts 
the heated air either out the outlet under the fuselage or into the cabin. 
Pressure builds up in the collector box and heated air leaks around the 
flapper, heating the cabin even when I don't want heat.  It would be great 
to be able to have negative pressure in the collector box but apparently, 
the two NACA scoops  feeding air in are much more efficient than the one 
exit supplied with the kit.  I've cut back the exit slightly to provide a 
bigger outlet and that helped some but I still have too much heat into the 
cabin.  Great heater though...  Any ideas?

Jerry Teitsma
Granby CO
jerryteits at comcast.net

> ****************************************