Today's Message Index:
----------------------
1. 12:49 AM - Re: Fuel return line attachment point with 912UL (zwakie)
2. 12:52 AM - 912S upgrade (Neil France)
3. 01:10 AM - Re: Fuel return line attachment point with 912UL (Brian Davies)
4. 04:25 AM - Re: Fuel return line attachment point with 912UL (Karl Heindl)
5. 04:54 AM - Re: Fuel return line attachment point with 912UL (rampil)
6. 05:56 AM - Re: Re: Fuel return line attachment point with 912UL (Graham Singleton)
7. 06:12 AM - Re: Re: Fuel return line attachment point with 912UL (Sidsel & Svein Johnsen)
8. 06:33 AM - Re: Re: Fuel return line attachment point with 912UL (Brian Davies)
9. 07:11 AM - Re: Fuel return line attachment point with 912UL (zwakie)
10. 07:32 AM - Re: Fuel return line attachment point with 912U (zwakie)
11. 07:51 AM - Re: Re: Fuel return line attachment point with 912UL (Raimo Toivio)
12. 08:36 AM - Re: Re: Fuel return line attachment point with 912U (Sidsel & Svein Johnsen)
13. 08:56 AM - Re: Re: Fuel return line attachment point with 912UL (Sidsel & Svein Johnsen)
14. 11:20 AM - Re: Fuel return line attachment point with 912UL (Robert Hatton)
15. 01:26 PM - Re: Fuel return line attachment point with 912UL (Jan de Jong)
16. 03:19 PM - Re: Re: Fuel return line attachment point with 912UL (Karl Heindl)
17. 06:47 PM - Jab FWF kit (jimpuglise@comcast.net)
Message 1
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| Subject: | Re: Fuel return line attachment point with 912UL |
Hi Karl,
[quote:ee27d1fd5f="kheindl"]Are you saying that I can change my plumbing and not
use a transducer in the return line ? [/quote:ee27d1fd5f]
Yes, you can. Actually, that's the whole purpose of the schema I posted
[quote:ee27d1fd5f="kheindl"]What then is the LAA recommendation [/quote:ee27d1fd5f]
I had the same question, so got in touch with the LAA before posting it here. I
had a brief e-mail conversation with Andy D. (I also sent him the schema).
Andy too was mentioning vapor-lock, and recommends to stick the sender as closely
to the carbs as possible.
If I decide to go this route, I will need to seek individual approval. Andy stated
that this mod almost certainly invalidates the PtF, and a new flight test
would be required.
Marcel
Visit - www.EuropaOwners.org
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Thanks to everyone who replied for their offers, I am now sorted.
Neil France.
do not archive
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| Subject: | Fuel return line attachment point with 912UL |
Karl,
Personally, I would stick to the recommended fuel supply configuration and
fit two Floscan transducers as detailed in the LAA approved mod. This
ensures a constant circulation of fuel in the length of pipe that joins the
two carbs together and avoids vapor locking as much as possible. If you are
prepared to accept the slightly increased risk of vapor locking, ( probably
more likely in the future with the changes to Mogas) you could modify the
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 installed
it under "standard aircraft practice" and they have not reported any
problems.
Regarding the location of the transducers, mine are in the engine
compartment, well wrapped in firesleeve, and have not given any problem.
Again, if you have the option (Trigear) it is preferable to mount them
outside the "hot" area.
The Floscan transducer is also used in marine applications and you can buy
the identical part, at a "reduced" price, from www.merlinequipment.com in
the UK. - Still very expensive!
Note that if you are using a FS450 configured for a single transducer you
will have to swap it for a double transducer model.
As usual, you pays your money and takes your choice!
Regards
Brian
_____
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@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,
I believe it helps a lot, 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
return line ? My fuel lines are as per factory recommendations apart from
gascolator and location of gascolator and fuel pump.
It would save a great deal of money; the tr. is now $ 332.- from ACS. I took
advantage of the ACS discount plus the $ 175.- rebate from JPI, and payed
'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, Karl
_____
From: bdavies@dircon.co.uk
Subject: RE: Europa-List: Fuel return line attachment point with 912UL
No Karl, you have not missed anything. If you install the fuel system as
recommended by the factory on a Rotax 921, you need two transducers so that
the return flow is subtracted from the total flow- leaving you with fuel
consumption. If you change the fuel supply configuration so that the return
line starts before the fuel gets to the carbs, you can then have a single
feed to the carbs. The fuel flow in this single feed is the fuel
consumption of the engine.
Hope that helps.
Brian Davies
_____
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@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,
I am also very confused about what has been said so far. I will be
installing a FS450 fuel flow gadget, and it calls for transducers in the
flow and return lines. I am not interested in how much fuel is flowing to
the engine, I am interested in the fuel consumption. And that consumption is
the difference between flow and return. Have I missed something ?
BTW, 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, 22 Apr 2009 18:00:53 +0100
>
<roberthatton1@googlemail.com>
>
> Hello Graham,
>
> 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
the
> 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?
The
> question being, 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, 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, April 22, 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, 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, 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, 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 configuration
> Graham
>
>
>
>
>
>======================
&g======
>
>
>
href="http://www.matronics.com/Navigator?Europa-List">http://www.matronhref
"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
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ronics.com
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17:25:00
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| Subject: | Fuel return line attachment point with 912UL |
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
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
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
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Checked by AVG - www.avg.com
Release Date: 04/22/09 17:25:00
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| Subject: | Re: Fuel return line attachment point with 912UL |
Hi All,
I know this has been discussed before, but the present discussion
seems to discount the fact that the 912s and the 914 return fuel
quantities are quite different. The 914 has a continuous, significant
return flow while the 912s has a negligible return flow. My
suspicion is that the flow rate in a 912s is below the range of accurate
measurement of a 201b floscan.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=240878#240878
Message 6
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| Subject: | Re: Fuel return line attachment point with 912UL |
rampil wrote:
>
> Hi All,
>
> I know this has been discussed before, but the present discussion
> seems to discount the fact that the 912s and the 914 return fuel
> quantities are quite different. The 914 has a continuous, significant
> return flow while the 912s has a negligible return flow. My
> suspicion is that the flow rate in a 912s is below the range of accurate
> measurement of a 201b floscan.
>
> --------
> Ira N224XS
>
You're probably right Ira :-)
Graham
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| Subject: | Re: Fuel return line attachment point with 912UL |
For what it is worth for the discussion, which I have not followed closely:
If you use the standard Europa supplied restrictor in the fuel return line
from 912S, the return flow is an amazingly high 10 liters (approx) / a
little less than 3 USG per hour even with full fuel tank pressure head on
the return line.
I use a Flowscan (don't have the type at hand) in only the supply line. For
instantaneous fuel consumption reading I have a valve on the return line
that I close. The reading then drops about 10 liters/hour after it has
stabilized (takes a few seconds due to the design of the engine driven fuel
pump). The flow reading is accurately calibrated. I close the valve only
at level flight at low to medium altitude to minimize the risk of vapour
lock.
Svein
LN-SKJ
-----Opprinnelig melding-----
Fra: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] P vegne av rampil
Sendt: 23. april 2009 13:53
Til: europa-list@matronics.com
Emne: Europa-List: Re: Fuel return line attachment point with 912UL
Hi All,
I know this has been discussed before, but the present discussion
seems to discount the fact that the 912s and the 914 return fuel
quantities are quite different. The 914 has a continuous, significant
return flow while the 912s has a negligible return flow. My
suspicion is that the flow rate in a 912s is below the range of accurate
measurement of a 201b floscan.
--------
Ira N224XS
Message 8
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| Subject: | Re: Fuel return line attachment point with 912UL |
Ira raises an obvious and simple solution that again a number of Europas
have- You could simply use the standard factory fuel configuration but omit
the reurn flow transducer. The FS450 has a very simple K factor adjustment
routine that would compensate for the error caused by not measuring return
flow. The difference between the return flow at low and high power settings
is probably negligible. If you are worried about it you could always
measure it during the fuel flow checks required before first flight.
This would not require a new mod (IMHO) as the fuel system would be
standard.
Brian
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of rampil
Sent: 23 April 2009 12:53
Subject: Europa-List: Re: Fuel return line attachment point with 912UL
Hi All,
I know this has been discussed before, but the present discussion seems to
discount the fact that the 912s and the 914 return fuel quantities are quite
different. The 914 has a continuous, significant return flow while the 912s
has a negligible return flow. My suspicion is that the flow rate in a 912s
is below the range of accurate measurement of a 201b floscan.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=240878#240878
Checked by AVG - www.avg.com
06:30:00
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| Subject: | Re: Fuel return line attachment point with 912UL |
[quote:5f76066678="Barry"]Hi Marcel,
Where is your nearest airfield. If I can creep in without Mode S or an ELT I can
come and show you as I am only in EDLM (near Stadtlohn).
Barry[/quote:5f76066678]
Hi Barry,
Awesome offer, I'd love to see your bird and more specifically you FF setup! My
home airfield is Hoogeveen (EHHO), so that's quite close to where you are.
I will drop you an email off-forum with my contact-details so we can make an appointment
for your visit. Also gives you the opportunity to have a look at my
G-BWON.
Looking forward to meeting you in person.
Marcel
Visit - www.EuropaOwners.org
Message 10
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| Subject: | Re: Fuel return line attachment point with 912U |
[quote:08f86472ee="skaajo"]If you use the standard Europa supplied restrictor in
the fuel return line from 912S, the return flow is an amazingly high 10 liters
(approx) / a little less than 3 USG per hour even with full fuel tank pressure
head on the return line.[/quote:08f86472ee]
Hi Svein,
You are the first to mention hard return flow numbers for a NON-914 engine, thanks!
I would never have expected 10 ltrs/hr fuel running through the return line
(I thought it would be MUCH less)
We know that return flow varies with RPM and power setting. Including Svein's return
flow number to this piece of knowledge, things seems to implicate that also
the VARIATION in return-flow might be considerably larger than previously
assumed. If this indeed is the case, correcting the K-factor for the single sender
with return flow numbers (established by doing some fuel flow measurements)
doesn't cut it either (that is simply too inaccurate to my likings).
This strengthens my believe that for obtaining accurate FF numbers, one either
has to go with 2 senders (in feed AND return line), or with one sender in a setup
as laid out in the schema that I posted (or is my reasoning incorrect anywhere?)
Since my engine is a 912[b:08f86472ee]UL[/b:08f86472ee], do you or anybody else
know if the return flow for the 912S and the 912UL are about the same? (I would
expect them to be close)
Marcel
Visit - www.EuropaOwners.org
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| Subject: | Re: Fuel return line attachment point with 912UL |
Svein,
What a nice example of creativenessity!
Who can have more that than an experimentalist?
I assume you surely have a warning system for closed returnline when the gear is
down? ;)
I assume when not in use you close both valves in fuel turn and returnlines?
Where is your return line valve? Near main valve?
Raimo OH-XRT
----- Original Message -----
From: "Sidsel & Svein Johnsen" <sidsel.svein@oslo.online.no>
Sent: Thursday, April 23, 2009 4:11 PM
Subject: RE: Europa-List: Re: Fuel return line attachment point with 912UL
For what it is worth for the discussion, which I have not followed closely:
If you use the standard Europa supplied restrictor in the fuel return line
from 912S, the return flow is an amazingly high 10 liters (approx) / a
little less than 3 USG per hour even with full fuel tank pressure head on
the return line.
I use a Flowscan (don't have the type at hand) in only the supply line. For
instantaneous fuel consumption reading I have a valve on the return line
that I close. The reading then drops about 10 liters/hour after it has
stabilized (takes a few seconds due to the design of the engine driven fuel
pump). The flow reading is accurately calibrated. I close the valve only
at level flight at low to medium altitude to minimize the risk of vapour
lock.
Svein
LN-SKJ
-----Opprinnelig melding-----
Fra: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] P vegne av rampil
Sendt: 23. april 2009 13:53
Til: europa-list@matronics.com
Emne: Europa-List: Re: Fuel return line attachment point with 912UL
Hi All,
I know this has been discussed before, but the present discussion
seems to discount the fact that the 912s and the 914 return fuel
quantities are quite different. The 914 has a continuous, significant
return flow while the 912s has a negligible return flow. My
suspicion is that the flow rate in a 912s is below the range of accurate
measurement of a 201b floscan.
--------
Ira N224XS
Message 12
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| Subject: | Re: Fuel return line attachment point with 912U |
Marcel,
<We know that return flow varies with RPM and power setting. Including
Svein's return flow number to this piece of knowledge, things seems to
implicate <that also the VARIATION in return-flow might be considerably
larger than previously assumed. If this indeed is the case, correcting the
K-factor for the <single sender with return flow numbers (established by
doing some fuel flow measurements) doesn't cut it either (that is simply too
inaccurate to my <likings).
The return flow is a function only of the fuel pressure in the return line
ahead of the restrictor. The fuel pressure sensor is in the main fuel line
between the carburetors, I assume, but even so the fuel flow rate's effect
on the pressure in the return is probably rather small. Therefore, the
return flow is (mainly) a function of the fuel pressure that you read off
the gauge. I simply do not remember whether the fuel pressure reading
differs much with RPM and load, but I will check that next time I fly. My
understanding is that the engine driven fuel pump on 912ULS is of the
constant pressure type, i.e. the return flow would not show much variation
(but I have been mistaken before!)
<This strengthens my believe that for obtaining accurate FF numbers, one
either has to go with 2 senders (in feed AND return line), or with one
sender in <a setup as laid out in the schema that I posted (or is my
reasoning incorrect anywhere?)
I am writing this from another PC than at home, so I don't have your
proposal at hand, or the purpose.
<Since my engine is a 912[b:08f86472ee]UL[/b:08f86472ee], do you or anybody
else know if the return flow for the 912S and the 912UL are about the same?
<(I would expect them to be close)
I don't know the answer to this, but it will depend on the restrictor and
the fuel pressure. You can easily check whether the fuel pump is the same
on the two engines by looking at their part numbers (Rotax web pages will
give you access to spare parts lists) and the Builders Manual (firewall
forward) on Europa's web pages should tell you whether the two engine
installations have the same restrictor - or an e-mail or phone call to Roger
at Europa should clarify it.
Regards
Svein
Visit - www.EuropaOwners.org
Message 13
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| Subject: | Re: Fuel return line attachment point with 912UL |
Raimo,
<I assume you surely have a warning system for closed returnline when the
gear is down? ;)
My gear is always down, it's a tri-gear! ;-)
<I assume when not in use you close both valves in fuel turn and
returnlines?
On most flights, I do not touch the fuel return close-off valve - it is left
wide open to ensure full fuel return to minimize risk of vapour lock.
During the test flying, I used it to find the best speed vs. fuel
consumption. I then operated over farm fields that with some skill and luck
would allow a reasonably safe landing in case the engine stopped due to
vapour lock (it never coughed). Now I use just once in a seldom while.
Nobody reading this should install such a valve without establishing where
you are with respect to the authorities. It is a critical interference in
the fuel system - if you forget to open it again you might be in
difficulties at some stage. When I close the valve, I keep my hand on the
valve until I have registered the reading and opened the valve again.
<Where is your return line valve? Near main valve?
Instead of the standard Europa fuel tank selector valve, I have an Andair
valve recessed in the top of the cocpit module tunnel immediately aft of the
throttle to select Main/Reserve/Off.
I have used the Europa supplied valve in the fuel return line instead
(blocked off one valve branch) and fitted it in the standard fuel selector
valve location, on the left side of the tunnel. I have fitted stoppers to
prevent turning the valve too far in either direction (i.e. only 90 degr
turn).
Regards,
Svein
Message 14
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| Subject: | Fuel return line attachment point with 912UL |
Hello Graham,
Don't doubt your own logic! Your explanation clarifies that element of the
debate up for me! Thank you for help.
Rob
Robert Hatton
email: roberthatton1@googlemail.com
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Graham
Singleton
Sent: Thursday, April 23, 2009 12:44 AM
Subject: Re: Europa-List: Fuel return line attachment point with 912UL
<grahamsingleton@btinternet.com>
Robert Hatton wrote:
> Hello Graham,
>
> 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
the
> 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?
The
> question being, 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, I am just
> trying to get my head around what has been said so far and the schematic.
>
>
> Robert
Hi Robert
I'm beginning to doubt my own logic on this thread :-\ but just think
about it for a moment. What we need to know is how much fuel the engine
uses/burns. All the rest of the fuel goes back to the tank. If you place
the Floscan, (I know of no other sensor that is acceptable) so that the
only fuel that passes through it is burnt by the engine then isn't that
what we want to know?
If fuel comes out of the tank and then goes back to the tank it hasn't
been used so won't be used to calculate fuel burnt by the totaliser.So
we don't need to know that, do we??
Graham
Message 15
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| Subject: | Re: Fuel return line attachment point with 912UL |
Return flow should be roughly proportional to the square root of fuel
pressure (differential pressure across flow restrictor).
Cheers,
Jan de Jong
Message 16
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| Subject: | Re: Fuel return line attachment point with 912UL |
Brian wrote:
>
> Ira raises an obvious and simple solution that again a number of Europas
> have- You could simply use the standard factory fuel configuration but om
it
> the reurn flow transducer. The FS450 has a very simple K factor adjustmen
t
> routine that would compensate for the error caused by not measuring retur
n
> flow. The difference between the return flow at low and high power settin
gs
> is probably negligible. If you are worried about it you could always
> measure it during the fuel flow checks required before first flight.
>
Okay=2C I think I will do just that. I will modify the wiring harness to al
low for a second transducer=2C but install another tr. ONLY if it turns out
I need one. Saves a lot of money and hassle and should be completely safe.
Karl
>
> Hi All=2C
>
> I know this has been discussed before=2C but the present discussion seems
to
> discount the fact that the 912s and the 914 return fuel quantities are qu
ite
> different. The 914 has a continuous=2C significant return flow while the
912s
> has a negligible return flow. My suspicion is that the flow rate in a 912
s
> is below the range of accurate measurement of a 201b floscan.
>
> --------
> Ira N224XS
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=240878#240878
>
>
>
>
>
>
>
>
>
>
>
> Checked by AVG - www.avg.com
> 06:30:00
>
>
===========
===========
===========
===========
>
>
>
Message 17
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Someone mentioned that they had the name of the guy who was building the FW
F kit for the Jabiru that Andy was selling.=C2- I talked to the Jab peopl
e at Lakeland and they would like the contact information.=C2- Apparently
, Andy had handled the whole deal and not let the other Jab people know who
the builder was.=C2- I picked up a card and will forward the information
if anyone has it.=C2- I already have my kit, but I know others are looki
ng for it.
Jim Puglise A-283
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