Today's Message Index:
----------------------
1. 12:55 PM - Relocating red cube (Dan Charrois)
2. 02:25 PM - Re: Relocating red cube (Kelly McMullen)
3. 03:58 PM - Re: Relocating red cube (Robert Jones)
4. 05:57 PM - Re: Relocating red cube (Tim Lewis)
5. 08:06 PM - Re: Relocating red cube (Dave Leikam)
Message 1
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| Subject: | Relocating red cube |
Hi everyone.
I've had ongoing fuel pressure fluctuation issues from time to time and am trying
to improve every piece of the puzzle to see if I can make them go away.
One of the things I'm doing is relocating my red cube fuel flow transducer from
the tunnel (as per plans) to the positive pressure side of the fuel pump (which
a lot of people do). According to the FT-60 red cube documentation which I
recently stumbled across (https://buy-ei.com/wp-content/uploads/2018/03/FT-60-Info-Rev-F.pdf)
they come right out and say "If the aircraft has a fuel pump(s),
the flow transducer MUST be installed downstream of the last fuel pump. Installing
the transducer upstream of the fuel pump(s) can cause vapor lock and
jumpy/inaccurate readings." That sentence definitely conflicts with the plans
for putting it in the tunnel, and makes me hopeful that this will make a difference
in taming my pressure fluctuations (not to mention should also help the
erroneous readings it gives when the electric boost pump is on).
But I'm struggling a bit with where exactly to put it. The two options for the
positive pressure side of the fuel pump mean either between the engine pump and
servo, or between the servo and spider. Most people I've heard who have moved
it have placed it between the servo and spider.
However, in the installation instructions for Electronics International's FP-5
(https://buy-ei.com/wp-content/uploads/FP-5L-II.pdf) which uses the red cube,
they suggest mounting locations. Applicable to my fuel injected engine without
a fuel return line from the servo, they say to refer to the drawings on page
17 or 18, both of which place the red cube between the fuel pump and servo.
Their drawings placing the cube between the servo and spider are marked as being
only applicable on aircraft with a fuel return line from the fuel servo.
Has this been noticed before and I'm just late to the party? Or do most people
who have been relocating the cube also have a fuel return line, which is why
it's been common to mount between the servo and spider? Does anyone know what
the reason might be to not install the red cube between the servo and spider
on an installation without a fuel return line from the servo?
Thanks!
Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213
Message 2
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| Subject: | Re: Relocating red cube |
Dan,
I used the location between the mechanical pump and the servo on a
Mooney I had before the RV, because that was where the STC instructions
said to put it. On my RV-10, I put it between the servo and the spider,
near the right front corner of the oil sump, before the line goes up to
the spider. Both locations delivered stable readings. I'd say
convenience to get relatively straight hose runs in and out of the cube
is the main point.
Kelly
On 1/20/2019 2:54 AM, Dan Charrois wrote:
>
> Hi everyone.
>
> I've had ongoing fuel pressure fluctuation issues from time to time and am trying
to improve every piece of the puzzle to see if I can make them go away.
>
> One of the things I'm doing is relocating my red cube fuel flow transducer from
the tunnel (as per plans) to the positive pressure side of the fuel pump (which
a lot of people do). According to the FT-60 red cube documentation which
I recently stumbled across (https://buy-ei.com/wp-content/uploads/2018/03/FT-60-Info-Rev-F.pdf)
they come right out and say "If the aircraft has a fuel pump(s),
the flow transducer MUST be installed downstream of the last fuel pump.
Installing the transducer upstream of the fuel pump(s) can cause vapor lock and
jumpy/inaccurate readings." That sentence definitely conflicts with the plans
for putting it in the tunnel, and makes me hopeful that this will make a difference
in taming my pressure fluctuations (not to mention should also help
the erroneous readings it gives when the electric boost pump is on).
>
> But I'm struggling a bit with where exactly to put it. The two options for the
positive pressure side of the fuel pump mean either between the engine pump
and servo, or between the servo and spider. Most people I've heard who have
moved it have placed it between the servo and spider.
>
> However, in the installation instructions for Electronics International's FP-5
(https://buy-ei.com/wp-content/uploads/FP-5L-II.pdf) which uses the red cube,
they suggest mounting locations. Applicable to my fuel injected engine without
a fuel return line from the servo, they say to refer to the drawings on page
17 or 18, both of which place the red cube between the fuel pump and servo.
Their drawings placing the cube between the servo and spider are marked as being
only applicable on aircraft with a fuel return line from the fuel servo.
>
> Has this been noticed before and I'm just late to the party? Or do most people
who have been relocating the cube also have a fuel return line, which is why
it's been common to mount between the servo and spider? Does anyone know what
the reason might be to not install the red cube between the servo and spider
on an installation without a fuel return line from the servo?
>
> Thanks!
>
> Dan
> ---
> Dan Charrois
> President, Syzygy Research & Technology
> Phone: 780-961-2213
>
>
>
>
>
Message 3
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| Subject: | Re: Relocating red cube |
I have an Airflow Performance FM300 on the front of a Barrett Cold Air Induc
tion manifold. Putting the Red Cube after the fuel Servo was a non starter f
or me because there was not enough room after the Servo to mount it without t
ight turns before and after the Red Cube. I finally mounted it the left side
on the fuel line run from the engine driven fuel pump to the Servo. This ga
ve me a fairly straight run before and after. I used Axel clamps to support t
he fuel lines at the front and back of the oil pan. The fuel lines were fire
sleeved of course and a got about 12 inches of fire sleeve to go over the R
ed Cube. I punched a hole in the sleeve for the wires and used hose clamps t
o secure the ends after everything was tightened down. You can see that I ha
d to fold it up to secure it.
I can=99t say how well this works because I am still working on wiring
avionics.
Robert Jones
> On Jan 20, 2019, at 01:54, Dan Charrois <dan@syz.com> wrote:
>
>
> Hi everyone.
>
> I've had ongoing fuel pressure fluctuation issues from time to time and am
trying to improve every piece of the puzzle to see if I can make them go aw
ay.
>
> One of the things I'm doing is relocating my red cube fuel flow transducer
from the tunnel (as per plans) to the positive pressure side of the fuel pu
mp (which a lot of people do). According to the FT-60 red cube documentatio
n which I recently stumbled across (https://buy-ei.com/wp-content/uploads/20
18/03/FT-60-Info-Rev-F.pdf) they come right out and say "If the aircraft has
a fuel pump(s), the flow transducer MUST be installed downstream of the las
t fuel pump. Installing the transducer upstream of the fuel pump(s) can cau
se vapor lock and jumpy/inaccurate readings." That sentence definitely conf
licts with the plans for putting it in the tunnel, and makes me hopeful that
this will make a difference in taming my pressure fluctuations (not to ment
ion should also help the erroneous readings it gives when the electric boost
pump is on).
>
> But I'm struggling a bit with where exactly to put it. The two options fo
r the positive pressure side of the fuel pump mean either between the engine
pump and servo, or between the servo and spider. Most people I've heard wh
o have moved it have placed it between the servo and spider.
>
> However, in the installation instructions for Electronics International's
FP-5 (https://buy-ei.com/wp-content/uploads/FP-5L-II.pdf) which uses the red
cube, they suggest mounting locations. Applicable to my fuel injected engi
ne without a fuel return line from the servo, they say to refer to the drawi
ngs on page 17 or 18, both of which place the red cube between the fuel pump
and servo. Their drawings placing the cube between the servo and spider ar
e marked as being only applicable on aircraft with a fuel return line from t
he fuel servo.
>
> Has this been noticed before and I'm just late to the party? Or do most p
eople who have been relocating the cube also have a fuel return line, which i
s why it's been common to mount between the servo and spider? Does anyone k
now what the reason might be to not install the red cube between the servo a
nd spider on an installation without a fuel return line from the servo?
>
> Thanks!
>
> Dan
> ---
> Dan Charrois
> President, Syzygy Research & Technology
> Phone: 780-961-2213
>
>
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>
>
>
Message 4
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| Subject: | Re: Relocating red cube |
I suspended my FP-5 in the line between the fuel servo and flow divider
IAW the drawing on page 20 of the FT-5 manual. I wrapped the transducer
with fire sleeve per the instructions. It has worked well in this
location for 4 years and over four hundred hours. Several other RV's
have done the same thing. I believe Airflow Performance recommended
this location to me.
This location eliminated the surging fuel flow readings I used to see.
My setup: RV-10, IO-540 C4B5, standard installation with stock Van's
fuel selector, stock RV-10 airflow performance boost pump in the tunnel,
mechanical fuel pump on the engine. Bendix fuel injection system. No
fuel return line.
--
Tim Lewis -- HEF (Manassas, VA)
CFI, A&P
RV-6A N47TD -- 1104 hrs - sold
RV-10 N31TD -- 1000 hrs
Dan Charrois wrote on 1/20/2019 4:54 AM:
>
> Hi everyone.
>
> I've had ongoing fuel pressure fluctuation issues from time to time and am trying
to improve every piece of the puzzle to see if I can make them go away.
>
> One of the things I'm doing is relocating my red cube fuel flow transducer from
the tunnel (as per plans) to the positive pressure side of the fuel pump (which
a lot of people do). According to the FT-60 red cube documentation which
I recently stumbled across (https://buy-ei.com/wp-content/uploads/2018/03/FT-60-Info-Rev-F.pdf)
they come right out and say "If the aircraft has a fuel pump(s),
the flow transducer MUST be installed downstream of the last fuel pump.
Installing the transducer upstream of the fuel pump(s) can cause vapor lock and
jumpy/inaccurate readings." That sentence definitely conflicts with the plans
for putting it in the tunnel, and makes me hopeful that this will make a difference
in taming my pressure fluctuations (not to mention should also help
the erroneous readings it gives when the electric boost pump is on).
>
> But I'm struggling a bit with where exactly to put it. The two options for the
positive pressure side of the fuel pump mean either between the engine pump
and servo, or between the servo and spider. Most people I've heard who have
moved it have placed it between the servo and spider.
>
> However, in the installation instructions for Electronics International's FP-5
(https://buy-ei.com/wp-content/uploads/FP-5L-II.pdf) which uses the red cube,
they suggest mounting locations. Applicable to my fuel injected engine without
a fuel return line from the servo, they say to refer to the drawings on page
17 or 18, both of which place the red cube between the fuel pump and servo.
Their drawings placing the cube between the servo and spider are marked as being
only applicable on aircraft with a fuel return line from the fuel servo.
>
> Has this been noticed before and I'm just late to the party? Or do most people
who have been relocating the cube also have a fuel return line, which is why
it's been common to mount between the servo and spider? Does anyone know what
the reason might be to not install the red cube between the servo and spider
on an installation without a fuel return line from the servo?
>
> Thanks!
>
> Dan
> ---
> Dan Charrois
> President, Syzygy Research & Technology
> Phone: 780-961-2213
>
>
Message 5
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| Subject: | Re: Relocating red cube |
Whatever you do, use flexible fire sleeve hose after transducer. DO NOT use ridged
aluminum fuel line after the transducer or before the spider like under
the fuel selector.
Suspend the transducer with minimal support for maximum flexibility
At least one -10 had engine failure due to cracked fuel line because of this.
It ended ok with emergency landing at an airport out of IFR. Lots of vibration
down there.
Dave Leikam
N89DA
> On Jan 20, 2019, at 7:53 PM, Tim Lewis <TimRVator@comcast.net> wrote:
>
>
> I suspended my FP-5 in the line between the fuel servo and flow divider IAW the
drawing on page 20 of the FT-5 manual. I wrapped the transducer with fire
sleeve per the instructions. It has worked well in this location for 4 years
and over four hundred hours. Several other RV's have done the same thing. I believe
Airflow Performance recommended this location to me.
>
> This location eliminated the surging fuel flow readings I used to see.
>
> My setup: RV-10, IO-540 C4B5, standard installation with stock Van's fuel selector,
stock RV-10 airflow performance boost pump in the tunnel, mechanical fuel
pump on the engine. Bendix fuel injection system. No fuel return line.
>
> --
> Tim Lewis -- HEF (Manassas, VA)
> CFI, A&P
> RV-6A N47TD -- 1104 hrs - sold
> RV-10 N31TD -- 1000 hrs
>
> Dan Charrois wrote on 1/20/2019 4:54 AM:
>>
>> Hi everyone.
>>
>> I've had ongoing fuel pressure fluctuation issues from time to time and am trying
to improve every piece of the puzzle to see if I can make them go away.
>>
>> One of the things I'm doing is relocating my red cube fuel flow transducer from
the tunnel (as per plans) to the positive pressure side of the fuel pump (which
a lot of people do). According to the FT-60 red cube documentation which
I recently stumbled across (https://buy-ei.com/wp-content/uploads/2018/03/FT-60-Info-Rev-F.pdf)
they come right out and say "If the aircraft has a fuel pump(s),
the flow transducer MUST be installed downstream of the last fuel pump.
Installing the transducer upstream of the fuel pump(s) can cause vapor lock
and jumpy/inaccurate readings." That sentence definitely conflicts with the plans
for putting it in the tunnel, and makes me hopeful that this will make a
difference in taming my pressure fluctuations (not to mention should also help
the erroneous readings it gives when the electric boost pump is on).
>>
>> But I'm struggling a bit with where exactly to put it. The two options for
the positive pressure side of the fuel pump mean either between the engine pump
and servo, or between the servo and spider. Most people I've heard who have
moved it have placed it between the servo and spider.
>>
>> However, in the installation instructions for Electronics International's FP-5
(https://buy-ei.com/wp-content/uploads/FP-5L-II.pdf) which uses the red cube,
they suggest mounting locations. Applicable to my fuel injected engine without
a fuel return line from the servo, they say to refer to the drawings on page
17 or 18, both of which place the red cube between the fuel pump and servo.
Their drawings placing the cube between the servo and spider are marked as
being only applicable on aircraft with a fuel return line from the fuel servo.
>>
>> Has this been noticed before and I'm just late to the party? Or do most people
who have been relocating the cube also have a fuel return line, which is why
it's been common to mount between the servo and spider? Does anyone know what
the reason might be to not install the red cube between the servo and spider
on an installation without a fuel return line from the servo?
>>
>> Thanks!
>>
>> Dan
>> ---
>> Dan Charrois
>> President, Syzygy Research & Technology
>> Phone: 780-961-2213
>>
>>
>>
>>
>>
>>
>
>
>
>
>
>
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