Hi! All
It may not be relevant but on G-PTAG there are no gills and since it is
the Jab 3300 it is entirely air cooled so all the cooling air has to
exit the lower rear part of the cowl with no bad effects on the
alternator situated at the rear of the engine.
Regards
Bob Harrison G-PTAG
Robt.C.Harrison
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Duncan
McFadyean
Subject: Re: Europa-List: Hey Guys...Speaking of drag...
<ami@mcfadyean.freeserve.co.uk>
<<Also, the 'gills' on the sides of the upper cowl seem to be counter
productive for cooling>>
Now your talking! I reckon these gills throw out a plume of air that (at
least locally) destroys the airflow down the side of the fus., creating
significant drag.
Has anyone blocked these off to see what speed advantage is gained?
Downside would be overheating/short life of alternator regulator, but
cooling for this could be separately provided for.
Duncan McF.
----- Original Message -----
From: "Terry Seaver (terrys)" <terrys@cisco.com>
Subject: RE: Europa-List: Hey Guys...Speaking of drag...
> <terrys@cisco.com>
>
> Hi Dave,
>
> I have long believed that moving the chin back to just in front of the
> radiators could help improve cooling on the ground, placing the
opening
> behind a more outboard section of the prop (more prop wash) and
reducing
> drag in the duct. Any gain in speed would just be icing on the cake
for
> me. In comparison to other aircraft of much greater horsepower, the
> lower duct inlet seems much larger than needed for only 100 HP. An
> efficient duct should be able to get by with a smaller duct, with less
> drag.
>
> Also, the 'gills' on the sides of the upper cowl seem to be counter
> productive for cooling (based on our instrumented mods). Closing them
> up should also reduce drag.
>
> Any pictures of Charles Staines modified cowl? Has he commented on
any
> changes to ground cooling?
>
> 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
> To: europa-list@matronics.com
> Subject: RE: Europa-List: Hey Guys...Speaking of drag...
>
>
> Terry,
>
> Chris Staines re-worked his 914 mono cowl last winter.
> Moved the "chin" back to just in front of the radiator and cut down
the
> size a bit. Also cleaned up the outflow area at the rear of the cowl.
> As the cowling is now closer to the muffler and exhaust pipes he had
to
> add some reflective heat shield material to the inside of the cowl.
> Looks neat, sort of Mustang like and seems to have improved cooling.
> As to speed, Chris thinks he has picked up 1 or 2 knots, really hard
to
> measure as so many things come into play.
> It is a lot of work for a small gain.
>
> Dave
>
>
>
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