Byron Brandon Ward wrote:

You might notice it as a slight trim change. The cooling might be
somewhat self regulating as I suspect slightly more down force is
required from the tail while climbing hence a lower pressure.

That's really what I meant. Does the extra trim drag overcome the
advantages of dumping the air out in this area.

Byron

Good question Byron. I would guess not but one would never
know. Looks complicated to calculate. You might find
that the air coming out adds to the stab downforce
as it should have some energy due to heating if the 
system works as well as it should.

I have been corrected on the more downforce idea.
What I thought was a need for more downforce was 
occuring while climbing at the same power level. 

What was actually happening was the airplane was 
flying slower during the climb so the downforce was 
decreased and needed to be increased by nose up trim.

Any rad system is self regulating to a degree because the
faster you go the more air the rad gets. On the other hand
top speed is more or less a function of the cube of HP
so the rate of increase of the cooling system does not keep
up with the increase in waste heat. At least I think :-) 
At first guess :-) Neil mentioned that he could not cool
the rotary in his airplane at 247 MPH.

In the P51 ostensibly  there was thrust from the cooling system 
exceeding the drag of the cooling system for a net increase 
in the speed and efficiency of the airplane.

We will just have to try it to find out I guess.
 
BTW things get a lot more interesting when you throw temperature
into the equation (P1 X V1) / T1 = (P2 X V2) / T2

Paul Lamar
 
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