Today's Message Index:
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1. 05:55 AM - Re: Gull Wing Mods (TELEDYNMCS@aol.com)
2. 02:10 PM - Re: Re: Gull Wing Mods (Dale Hetrick)
Message 1
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| Subject: | Re: Gull Wing Mods |
In a message dated 5/2/2009 3:08:12 A.M. Eastern Daylight Time,
jabiruengine-list@matronics.com writes:
Have you done this mod????
Greetings,
I have a 3300 installed in a Europa. About two years ago I modified the
"gull wings" to include a hole in them about one sq. in. or so in total area
on each wing. The shape of the hole resembles a pentagram with the pointy
side towards the crankcase. This allows air to spill down the inside of the
heads and between the cylinder barrels. While the gull wing is not
completely removed, this modification did help with lowering head temps in climb.
I
recall I tested with the gull wings removed completely and it did not help
my set up.
Last fall I added a "step" or reverse scoop to my lower cowl just before
the exit hole. This step, or reverse scoop, serves to create an area of low
pressure at the point where the cooling flow exits the lower cowl. The
effect is similar to the "lips" often seen on lower cowls, but is more
aerodynamic. The step was molded onto the lower cowl by carefully shaping foam,
then glassing over it and painting. It extends about 4" below the lower cowl
and belly of the aircraft and is approximately 10" wide, equal to the width
of the exit hole. This helped significantly. Essentially, what I did was
copy what Mooney, Cirrus, Columbia and other "modern" aircraft are doing in
regard to their lower cowls to enhance exit cooling flow. It also hides the
exhaust stacks and helps to hide the Europa's lower stainless firewall and
nose gear leg gusset from the relative wind in climb and cruise attitudes.
Both the lower fire wall and nose gear leg gusset were flat to the airflow
in climb and somewhat exposed in cruise. Manometer testing showed that
these two components were causing an area of high pressure at the exit hole
prior to the installation of the step. The change in the gull wings and the
addition of the step on the lower cowl reduced the ambient pressure inside
the internal head cooling ducts, increasing flow, and lowering head temps by
an average of 25F. Pictures available upon request.
Regards,
John Lawton
Whitwell, TN (TN89)
Europa N245E - Flying
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Message 2
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| Subject: | Re: Gull Wing Mods |
Hi John,
Your idea(s) seem very sound to me, therefore I would appreciate the
proffered photos.
Many thanks,
Dale
Tri-Gear/3300
----- Original Message -----
From: TELEDYNMCS@aol.com
To: jabiruengine-list@matronics.com
Sent: Saturday, May 02, 2009 5:50 AM
Subject: JabiruEngine-List: Re: Gull Wing Mods
In a message dated 5/2/2009 3:08:12 A.M. Eastern Daylight Time,
jabiruengine-list@matronics.com writes:
Have you done this mod????
Greetings,
I have a 3300 installed in a Europa. About two years ago I modified
the "gull wings" to include a hole in them about one sq. in. or so in
total area on each wing. The shape of the hole resembles a pentagram
with the pointy side towards the crankcase. This allows air to spill
down the inside of the heads and between the cylinder barrels. While the
gull wing is not completely removed, this modification did help with
lowering head temps in climb. I recall I tested with the gull wings
removed completely and it did not help my set up.
Last fall I added a "step" or reverse scoop to my lower cowl just
before the exit hole. This step, or reverse scoop, serves to create an
area of low pressure at the point where the cooling flow exits the lower
cowl. The effect is similar to the "lips" often seen on lower cowls, but
is more aerodynamic. The step was molded onto the lower cowl by
carefully shaping foam, then glassing over it and painting. It extends
about 4" below the lower cowl and belly of the aircraft and is
approximately 10" wide, equal to the width of the exit hole. This helped
significantly. Essentially, what I did was copy what Mooney, Cirrus,
Columbia and other "modern" aircraft are doing in regard to their lower
cowls to enhance exit cooling flow. It also hides the exhaust stacks and
helps to hide the Europa's lower stainless firewall and nose gear leg
gusset from the relative wind in climb and cruise attitudes. Both the
lower fire wall and nose gear leg gusset were flat to the airflow in
climb and somewhat exposed in cruise. Manometer testing showed that
these two components were causing an area of high pressure at the exit
hole prior to the installation of the step. The change in the gull wings
and the addition of the step on the lower cowl reduced the ambient
pressure inside the internal head cooling ducts, increasing flow, and
lowering head temps by an average of 25F. Pictures available upon
request.
Regards,
John Lawton
Whitwell, TN (TN89)
Europa N245E - Flying
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