Message-ID: <001101be8e73$a2fe2360$06c295cf@bill>
From: "William T Bartlett" <wtbart@olympus.net>
To: <lancair.list@olsusa.com>
References: <19990424041454.AAA22625@truman.olsusa.com>
Subject: Cowl flap?
Date: Sat, 24 Apr 1999 09:25:34 -0700
Mime-Version: 1.0

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Some builders experience engine heat problems on climb out, but have normal
temp at cruise, which is logical. If the cooling air intake or exit (most
probable) is too small it must be enlarged to provide adequate cooling
at climb, which creates unnecessary drag at cruise so cowl flaps are
indicated, but the LC20s don't lend themselves to easy cowl flap installation.

Because of past experience I hinged my oil check door perpendicular to
the aircraft axis (yes it is flat enough) and the other day I forgot to
latch my door and on climb out the door stood up at about
70° to the cowl.
This is fairly far forward of the canopy so I don't think it was caused
just by the low presure area caused by the canopy. My oil temp is not
high on climb out, but was considerably lower with the door open.

All American Electronics sells ($+-5) various powerful, little (4 oz),
geared, 12V motors, with arms on them that would be plenty strong enough to
close the door in flight.  The 235 has way too big an openings for
cooling air, I saw a 235/320 from Oragon that had cut their
area in half.
The 32/360 have more apropriate sizes, but probbly could benifit from the
"cowl flap".

Although I have two of the Servos I haven't done this modification because
I don't want to paint the door where I remove the latch, and have been too
lazy. I wouldn't gain much unless I also reduced the size of the intakes and
that requires painting too.

Bill N7WB


>Don also cut a some hole on the
>lower cowling to allow more hot air to exit.  The seemed to do the trick,
>CHT's on the third flight were finally within acceptable levels.


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