Brian and Marcel=2C
Many thanks for responding to my questions. I am undecided and I think I wi
ll sit on this for a while. I have done all the preparatory work for the in
strument and wiring. I may install the feed line transducer just aft of the
mech. fuel pump=2C the engine is cool in that area. If I install a second
tr.=2C then this would go in the tunnel. My gascolator and el. pump are loc
ated next to the nosewheel bungee.
Best regards=2C Karl
From: bdavies@dircon.co.uk
Subject: RE: Europa-List: Fuel return line attachment point with 912UL
Date: Thu=2C 23 Apr 2009 09:02:33 +0100
Karl=2C
Personally=2C I would stick to the recommended fuel supply configuration an
d fit two Floscan transducers as detailed in the LAA approved mod. This en
sures a constant circulation of fuel in the length of pipe that joins the t
wo carbs together and avoids vapor locking as much as possible. If you are
prepared to accept the slightly increased risk of vapor locking=2C ( proba
bly more likely in the future with the changes to Mogas) you could modify t
he fuel system as described by Marcel and then you only need one transducer
. My understanding is that this would require a new mod approval but I do
know that a number of aircraft are flying with this arrangement having inst
alled it under "standard aircraft practice" and they have not reported any
problems.
Regarding the location of the transducers=2C mine are in the engine compart
ment=2C well wrapped in firesleeve=2C and have not given any problem. Agai
n=2C if you have the option (Trigear) it is preferable to mount them outsid
e the "hot" area.
The Floscan transducer is also used in marine applications and you can buy
the identical part=2C at a "reduced" price=2C from www.merlinequipment.com
in the UK. - Still very expensive!
Note that if you are using a FS450 configured for a single transducer you w
ill have to swap it for a double transducer model.
As usual=2C you pays your money and takes your choice!
Regards
Brian
From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-serv
er@matronics.com] On Behalf Of Karl Heindl
Sent: 23 April 2009 01:25
Subject: RE: Europa-List: Fuel return line attachment point with 912UL
Brian=2C
I believe it helps a lot=2C but I have to think about it a little more. Are
you saying that I can change my plumbing and not use a transducer in the r
eturn line ? My fuel lines are as per factory recommendations apart from ga
scolator and location of gascolator and fuel pump.
It would save a great deal of money=3B the tr. is now $ 332.- from ACS. I t
ook advantage of the ACS discount plus the $ 175.- rebate from JPI=2C and p
ayed 'only' $310 for the complete FS450
single transducer kit.
What then is the LAA recommendation and what about Ian's mod submission to
the LAA ?
Cheers=2C Karl
From: bdavies@dircon.co.uk
Subject: RE: Europa-List: Fuel return line attachment point with 912UL
Date: Wed=2C 22 Apr 2009 19:12:24 +0100
No Karl=2C you have not missed anything. If you install the fuel system as
recommended by the factory on a Rotax 921=2C you need two transducers so t
hat the return flow is subtracted from the total flow- leaving you with fue
l consumption. If you change the fuel supply configuration so that the ret
urn line starts before the fuel gets to the carbs=2C you can then have a si
ngle feed to the carbs. The fuel flow in this single feed is the fuel cons
umption of the engine.
Hope that helps.
Brian Davies
From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-serv
er@matronics.com] On Behalf Of Karl Heindl
Sent: 22 April 2009 18:22
Subject: RE: Europa-List: Fuel return line attachment point with 912UL
Hi=2C
I am also very confused about what has been said so far. I will be installi
ng a FS450 fuel flow gadget=2C and it calls for transducers in the flow and
return lines. I am not interested in how much fuel is flowing to the engin
e=2C I am interested in the fuel consumption. And that consumption is the d
ifference between flow and return. Have I missed something ?
BTW=2C I am looking for another Floscan 201 A6 with a matching K-factor.
Karl
> From: roberthatton1@googlemail.com
> To: europa-list@matronics.com
> Subject: RE: Europa-List: Fuel return line attachment point with 912UL
> Date: Wed=2C 22 Apr 2009 18:00:53 +0100
>
ail.com>
>
> Hello Graham=2C
>
> I am following this thread for I shall also be looking at fitting a fuel
> flow meter. Could I ask you to elaborate on your comment about ignoring t
he
> return flow for you are only measuring the fuel to the engine. I think I
> understand that with the placement of the Flowscan (from Marcel's the
> schematic) no problem in measuring the fuel going to the engine. But with
> the fuel coming back via the return line will that not eventually (after
> going through the system) go back to the engine again via the Flowscan? T
he
> question being=2C are the amounts so small not to worry about it and does
this
> just build in a safety margin? Sorry to sound thick on this=2C I am just
> trying to get my head around what has been said so far and the schematic.
>
>
> Robert
>
> Robert Hatton
> email: roberthatton1@googlemail.com
> US Cell: +01 303 906 9395
> UK Mobile: +44 79 66 184171
>
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Graham
> Singleton
> Sent: Wednesday=2C April 22=2C 2009 1:12 PM
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Fuel return line attachment point with 912UL
>
> <grahamsingleton@btinternet.com>
>
> The question is=2C how does ignoring the return flow affect the accuracy
> >> of the fuel flow instrument? It depends on the quantity of the return
> >> flow of course. Is there any data about this? Maybe in the rotax
> >> maintenance manuals?
> >>
> >
> > That's indeed the question I so far have not found an answer to. The
> > only thing I was told by different people is that return flow varies
> > with RPM=2C but no hard numbers on return flow have made it my way. So
> > basically I *know* there will be an inaccuracy when ignoring return
> > flow=2C but *do not know* just how large this inaccuracy is (hence my
> > attempt to come up with something better for a single sender setup).
> >
> > Marcel
> >
> Marcel
> The return flow does not affect your fuel flow to the engine and that is
> what you are measuring. So you can forget about it with this configuratio
n
> Graham
>
>
>
>
>
>======================
&g======
>
>
>
href="http://www.matronics.com/Navigator?Europa-List";>http://www.matronhr
ef="http://forums.matronics.com";>http://forums.matronics.com
href="http://www.matronics.com/contribution";>http://www.matronics.com/c
. Checked by AVG - www.avg.com
>http://www.matronics.com/Navigator?Europa-List
ronics.com
ww.matronics.com/contribution
href="http://www.matronics.com/Navigator?Europa-List";>http://www.matronhr
ef="http://forums.matronics.com";>http://forums.matronics.com
href="http://www.matronics.com/contribution";>http://www.matronics.com/c
Checked by AVG - www.avg.com
Release Date: 04/22/09 17:25:00
|