Hi Dave,
I am surprised Chris actually increased the gill openings. We found
them very harmful to engine cooling (in flight) and closed them off
(three of the four). The air from the two round inlets (on each side of
the prop) would flow across the top of the engine and out the gills,
without cooling anything significant. After closing them off, we saw
the cooling air from the round inlets go down the back of the engine and
out the bottom of the cowl, also without providing much cooling of
anything useful. After closing off the area behind the engine (between
the foot wells), we finally got sufficient cooling air past the
cylinders and exhaust, lowering oil temps 20 degF and peak in-cowl temps
200 degF.
Remember, the Rotax has liquid cooled heads and air cooled cylinders. It
is the air from the small round inlets that is supposed to cool the
cylinders (and exhaust system), not pass directly out of the cowl
through the gills.
Even after closing off the gills and between the foot wells, the
temperatures at the top of the cowl (carbs, ignition, etc) remained
within a few degrees of ambient.
Regards,
Terry Seaver
A135
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
Dave_Miller@avivacanada.com
Subject: RE: Europa-List: Hey Guys...Speaking of drag...
Hi Terry,
One of Chris's objectives was to improve cooling on the ground, he seems
to have done this.
He stretched the two circular openings in the centre of the cowl, and
actually doubled the number of "gills".
He was thinking of writing an article for the Europa Flyer, but is a
particularly busy person, and of course this is very much a trial and
error sort of mod, so it may not meet with unanimous approval.
I'm very low tech and will probably be the last person in the world
without a digital camera or cell phone, but I've got some photos of
Chris's plane around the house and would be happy to stick them in the
mail.
Dave
|