I neglected to mention that when we closed off our gills we also opened
up the lower cowl exit area and baffled the area between the foot wells
to force air from the eye ball inlets down past the cylinders, then the
muffler, and finally out the bottom of the cowl. This dropped in-cowl
temps from 450 deg F to about 250 max and lowered oil temps in climb by
20 deg F.
Regards,
Terry
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Duncan &
Ami McFadyean
Sent: Saturday, September 22, 2007 12:13 PM
Subject: Re: Europa-List: Monowheel speed kit
--> <ami@mcfadyean.freeserve.co.uk>
<<Closing off the gills would be the first thing (they add no value to
the plane). >>
I tried that.
It made no difference to CHT, oil or water temps. But why would it;
those systems are cooled independently to what goes on under the cowl.
However, (with the 912S air shroud fitted) the cylinder wall
temperatures went up SUBSTANTIALLY. So much so that I could easily
believe that on a hot day and an extended full power climbout they would
quickly exceed the maximum permitted (190C). Fortunately, I never
experienced that configuration before finding out this.
By closing the gills, 'competition' for cowl exit area is increased.
On the other hand, the temparature of the alternator regultator didn't
seem to be affected at all.
Duncan Mcf.
----- Original Message -----
From: Terry Seaver (terrys)
Sent: Thursday, September 20, 2007 10:39 PM
Subject: RE: Europa-List: Monowheel speed kit
I believe the biggest improvement in reducing drag would be found in the
engine cowl area. Closing off the gills would be the first thing (they
add
no value to the plane). Second would be to clean up the radiator
opening
and following duct, it is too large for the size of this engine and is
rather messy. Then clean up the radiator exit, it is very messy back
there.
We carefully installed the Kim Prout main gear fairings and saw ZERO
improvement in cruise speed, which leads me to believe that the lower
cowl
exit is so turbulent that fairing in the main gear (or even retracting
it)
has little value. A magazine flight test on the Europa motor glider
reported that there was no improvement in glide performance gear up vs
gear
down, which further supports my suspicion on the cowl problems.
regards,
Terry Seaver
N135TD, XS mono-wheel with 912S.
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