I have 1 sender after the return below the highest point. So any vapour risi
ng to the top of the circuit is returned via the return which is after the h
igh point but before the fuel flow sender. The pipe after the sender is very
short and this setup has given no problems even when hot. The accuracy of t
he fuel flow is brilliant. This setup was recommend by a Rotax expert. I hav
e a xs firewall forward setup.
Kevin Challis
On 26 Sep 2012, at 17:46, Neville Eyre <neveyre@aol.com> wrote:
> Hi Juergen,
> Re routing the return line in this way is negating the main reason to have
it in the first place.
> The main reason for the return line is to purge vapour and hot fuel trappe
d in the lines close to the carbs, back into the tank. The Manual instructs t
o have the return line as close as possible to the port [ second in the line
] carb, so all of it gets purged.
> Returning fuel to the tank from the line before the transducer, leaves al
l the fuel downstream of that, forward of the firewall to the carbs, in the h
ot cowl after shut down.
> When plumbed as per Manual, the hot fuel gets returned to the tank, with f
resh, cool fuel feeding the engine, [ and cooling the lines at the same time
].
> If installed in the standard Europa XS cowl, this area gets up to, and som
etimes above 80C for a while after shut down on a hot day. If installed as y
ou are describing, you have an accident waiting to happen. [vapour lock in t
he climbout after a short shutdown].
> Fire sleeve / insulation of the lines is only a half way fix.
> Regards,
> Nev.
>
>
> -----Original Message-----
> From: europapa <experimental@online.de>
> To: europa-list <europa-list@matronics.com>
> Sent: Tue, 25 Sep 2012 22:51
> Subject: Europa-List: Re: fuel flow
>
>
> I made my experiences with the installation of only one transducer.
> I am using the floscan transducer and a separate fuel computer.
> The quantity of fuel that returns may nearly be constant ( not in my
> installation, as the fuel pressure is for any reason not always the same )
but
> you can only trick the computer with an matching K-factor for only one def
ined
> power setting.
> One of the most important questions to the fuel computer for me is: how mu
ch
> fuel is left in tank after for example two hours flying?
> But in a flight we use different power settings so the number the computer
> showed was rubbish.
> So I redesigned the fuel routing:
> The fuel line from the mechanical fuel pump now goes all the way back thro
ugh
> the fire wall to the cavity where the fuel select switch is.
> There I installed a y peace. One line goes with the restrictor in it back t
o the
> tank while the other goes in a strait line and with the transducer in line
back
> through the fire wall to the carburetors.
> So only the fuel used by the carburetors is measured and the accuracy is
> outstanding. After burning 40 liters there is only a discrepancy of half a
> liter.
> And I have too all the benefits Raimo mentioned and I agree with him that t
his
> system should be mandatory.
> Sorry for my bad phrasing.
>
> Juergen
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=383996#383996
>
>
>
>
>
>
>
> arget=_blank>http://www.matronics.com/Navigator?Europa-List
> p://forums.matronics.com
> blank>http://www.matronics.com/contribution
>
>
>
>
>
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