Jeff,
If you are a good eater you need a good bowel movement. You may create
openings in the cowling for air entree, if you don't create an excit the
air will stay immobile under the cowling. For instance: if you enlarge
the forward round inlets as I did then the surface for air intake
enlarges by the square diameter. Second thing to do like I did: In the
original cowling concept I felt some warm air entering trough the wheel
well and the landing gear arm sleeve. After my modification I can put
the Jeppensen airfield leaves on the sleeve and they stay fixed because
there is a suction outwards now. I also measured under cowling
temperatures and after my mods they are the same as outside temperatures
+ - 5=B0C. Terry Seaver experimented also in this matter and finaly cut
down the end of the inner aluminium duct. I wish you courage and fun
during your experiment.
Best regards,
Karel Vranken, F-PKRL actually 160 hours. 912 ULS Airmaster CSU
----- Original Message -----
From: JEFF ROBERTS
To: europa-list@matronics.com
Sent: Thursday, July 03, 2008 10:34 PM
Subject: Europa-List: Cooling & Cowling
Since I struggled with the cooling on my 912-S Tri gear for so very
long I thought I'd throw my thoughts into this subject. I have found the
air cooling of the fins to be inadequate. If you look at the round
inlets in relation to where the top of the engine sits you will find
they are too low and too outside. After trying everything to get mine to
cool on the ground and in the climb I finally got mad and took a drummel
tool to the inlets and opened them up a bit to the top and in towards
the spinner. For now... she looks a little sad but my CHT's instantly
dropped about 10 to 15 degrees. I'm going to work on the inside of these
holes next to provide an expanding 1" wall to eliminate any turbulence
of the incoming air flow.
Believe me I'v tried everything everyone has mentioned here from
closing up all the gaps around the rad to closing the gills. Nothing did
more for taxi and climb cooling than raising these holes. If you look at
all the LSA's with rotax engines the intakes are higher so the air can
get to the top of the engine before it's pulled or pushed down through
the fins. The real solution would be for rotax to start selling plenums
like the Jab's then route the hoses to fit over them.
Regards,
Jeff R.
A258 - N128LJ / Gold Rush 130 hours and enjoying every flight more.
PS. Jeff of Baby blue... If your making a mold that turns out
successfully try and saving it. I would love a better designed cowl. ;0)
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