Hi Bob
One more point:
"Clean system flows were well in spec. before flight testing."
Are you really sure you checked fuel system and it was within specs? Did
you simulate ambient atmospheric pressure to high altitude? You can follow
Rotax check of cheating fuel pressure regulator to think it is at high
altitude which is probably OK, but again as I have said many times,
gallons per hour flow on a 914 is moot. You need to measure that fuel
pressure is over airbox pressure by 2 to 5 PSI. For actual test you need
to simulate airbox pressure, so do that to 115HP level, and drop ambient
to that of 18K, Did you do this?
Did you at least follow Rotax check of increasing airbox pressure to 115%
level and see that differential pressure is 2 to 5? (knowing full well
that at higher altitude it may very well not perform)
Or did you measure fuel flow into a bucket that is about as useless in
determining fuel system performance as is toting that bucket on the tail
of plane?
Believe me I am not trying to be nasty, I am trying to be "Assertive" in
trying to help you and others to get in tune what 914 needs are.
If one does not have differential gauge (which you can just cheat input
for airbox pressure and same to fuel pressure regulator) which after cheat
you can just see that needle is between 2 and 5, or you can cheat
regulator and note reading, note ambient pressure and measure fuel
pressure to carbs, Rotax manual tells how to do calculation.
Many believe in making things as simple as possible. That may not be a
great philosophy. Albert Einstein had a much better one "Make things as
simple as possible, not simpler". As far as 914, don't forget the last
part.
If beyond scope of Builder/Pilot, search out someone who can help out. It
is OK to not understand something complete and still be an effective user,
instance most users of modern automobiles. That said to set up and
engineer such a machine, for best results best be intimate familiar.
Ron Parigoris
> Regards
> Bob Harrison G-PTAG
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Graham
> Singleton
> Sent: 03 November 2007 10:29
> To: europa-list@matronics.com
> Subject: Re: Europa-List: fuel system
>
> <grahamsingleton@btinternet.com>
>
>
>
> rparigor@suffolk.lib.ny.us wrote:
>>
> Ron
> a lot of good sense in what you say.
> The Andair gascolators have 120 mu mesh, because Rotax specify minimum
> of 100mu filters. They couldn't buy 100mu at the time I discussed it
> with them. Those nice Mr Funnel filters are around 70mu (if I remember
> right) and they WILL allow dust through that will block an Andair Mini.
> I know of one blockage with a 914, caused by rust from a Jerry can. The
> Mini is probably OK for 912S but not 914 with the high recirculating
> flow rate.
> Graham
>
>> Did you clean the filters in your fuel pump after a few hours of
> running?
>> If you didn't probably worth while. See:
>> http://contrails.free.fr/engine_914_fuel_syst_test_en.php
>> for some good 914 info
>> I would not consider using Mini, in a perfect clean world will
> probably
>> work, but very little surface area, stick at least with 375s or
> supplied
>> filters instead of Mini.
>> For info on this post see folders:
>> 914 modular fuel system
>> Spring loaded down detent
>>
>> Ron Parigoris
>>
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>
> --
> Graham Singleton
>
> Tel: +441629820187
> Mob: +447739582005
>
>
>
>
>
>
> --
> 02/11/2007 21:46
>
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