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<DIV><FONT face=Arial size=2>I set up my cowls with 2 times the exit air area,
as intake area.</FONT></DIV>
<DIV><FONT face=Arial size=2>A backwards scoop would work for exit
air. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So does a scoop that</FONT><FONT face=Arial
size=2> projects into the cowl - sort of </FONT></DIV>
<DIV><FONT face=Arial size=2>an intake scoop, </FONT><FONT face=Arial
size=2>installed backwards, and on the inside </FONT></DIV>
<DIV><FONT face=Arial size=2>of the cowl. With a </FONT><FONT
face=Arial size=2>glas cowl, they are fairly easy to make.
</FONT></DIV>
<DIV><FONT face=Arial size=2>For a 1/2 inch wide </FONT><FONT face=Arial
size=2>exit air scoop, pick a spot to rear of engine, </FONT></DIV>
<DIV><FONT face=Arial size=2>and plan to cut out </FONT><FONT face=Arial
size=2>a rectangular piece out of the cowl,</FONT><FONT face=Arial size=2>
about </FONT></DIV>
<DIV><FONT face=Arial size=2>1/2 inch wide, </FONT><FONT face=Arial
size=2>about 2 to 3 </FONT><FONT face=Arial size=2>inches long (longitudinal
</FONT><FONT face=Arial size=2>direction). </FONT></DIV>
<DIV><FONT face=Arial size=2>Cut ONLY </FONT><FONT face=Arial size=2>the
two long </FONT><FONT face=Arial size=2>sides, and the 1/2 inch side to
rear. </FONT></DIV>
<DIV><FONT face=Arial size=2>Push the </FONT><FONT face=Arial size=2>front end
of </FONT><FONT face=Arial size=2>the cut glas into the cowl about 3/8
inch.</FONT></DIV>
<DIV><FONT face=Arial size=2>Install </FONT><FONT face=Arial size=2>two hard
</FONT><FONT face=Arial size=2>balsa triangular pieces at each side, 2 to 3
</FONT></DIV>
<DIV><FONT face=Arial size=2>inches </FONT><FONT face=Arial size=2>wide,
</FONT><FONT face=Arial size=2>and 3/8 at base of triangle.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Or, you can cut the front end of the
rectangular scoop shape, </FONT></DIV>
<DIV><FONT face=Arial size=2>and make an air intake scoop.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Later, Ron Lockhart</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=aquennoz@ipa.net href="mailto:aquennoz@ipa.net">Adam Quennoz</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">Pattern List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, February 04, 2003 8:34
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Thoughts about air scoops.</DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It seems the trend these days are air
scoops. Before a scoop is effective, the area of the air exit must
equal or exceed that of the air intake thus allowing a positve air flow to
occur. With all the scoops people are putting on the nose of the
aircraft, there must be a pretty good sized hole somewhere for the air to
escape. There are cheek scoops, chin scoops and now with the concern of
cooling the crank cases, there are scoops above the engine compartment.
I call them "nose scoops". </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Has anyone thought of making EXITS on
the top of the nose above the engine, and/or exits on the cheeks?
Basically put the scoops on backwards. The air flowing over the
backward facing scoop would actually create lower pressure inside the engine
compartment allowing a larger volume of air to enter the chin
scoop. The air entering the chin scoop can flow all around the engine as
it makes way to the exits of the engine compartment, and what's
left can flow down the pipe tunnel. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'd like to hear what others have to say
about this idea. I'm thinking of trying it on my pattern
plane.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Regards,<BR>Adam Quennoz<BR>AMA 383866<BR>IMAC
2439<BR>NSRCA 3546<BR></FONT></DIV></BLOCKQUOTE></BODY></HTML>