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Posted

Has anyone installed a removeable auxiliary fuel tank in a Jabiru? I am looking at a Turtle-Pac Turtle Buddy or Big Buddy in particular. When I first considered it, I though "Great. It can plumb into the header tank!" Thinking more on it, it would be better from an operational point of view to transfer aux fuel into wing tanks as soon as room allows. That way, if there is a problem with the aux tank/pump, it will be picked up early allowing a Plan B to be put into action. Any thoughts/experience/suggestions/questions welcome.

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Posted (edited)

That's good thinking and transfer all fuel before PNR then you are sure of being able to use it. The same logic applied to my Twin Comanche with tip tanks.  Try to make sure you don't vent any overboard when transferring. Nev

Edited by facthunter
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Posted

I have been thinking about doing this and decided that the most reliable way is plumb a Tee into one heafer tank feed line and then pump the fuel into the tank. 3-4 psi would be more than enough to overcome the head pressure. Just need to make sure you don't jettison fuel overboard by overfilling.

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Posted

With a tap in the line you could then fill the Aux tank from the wing tanks when you wanted to fill it.

Posted
7 minutes ago, Tasmag said:

I have been thinking about doing this and decided that the most reliable way is plumb a Tee into one heafer tank feed line and then pump the fuel into the tank. 3-4 psi would be more than enough to overcome the head pressure. Just need to make sure you don't jettison fuel overboard by overfilling.

Good idea. I'll see what the supplied Turtle-Pac pump does pressure wise.

Posted
6 minutes ago, Tasmag said:

With a tap in the line you could then fill the Aux tank from the wing tanks when you wanted to fill it.

Another interesting idea Tasmag. As I think a non return valve would be required (to avoid this very thing in flight), a filling tap could be put in parallel with the NRV. The downside is an additional point of possible failure.

Posted

My Zephyr had a 35 Litre auxiliary tank in it, when I purchased her.

As several erlier commentators have cautioned, the problem with an auxiliary tank transfiguring fuel in flight,  is that you must make more than enough space (use fuel) in your main tank, to allow the fuel to be transferred, without jettisoning some of it overboard.

My solution was to design a circular fuel system:

As luck would have it, the installer of the auxiliary tank also, installed a separate filling point, quit high up on the fuselage (significantly higher than the main tank).

I blocked off the "breather" for the main tank  and blocked the breather for the auxiliary tank.

I Installed a new breather, located close to the top of the fill tube for the main tank.

I connected this new breather, via some small bore metal hydraulic tube (brake line) to an adaptor on the auxiliary tank fill pipe.

I installed a second similar adapter, just above the first - this  second adaptor became the breather for both tanks. Routed the pipe from this second point, as high as I could get it in the fuselage, two loops and then exit straight down out of the lower fuselage.

The auxiliary tank filler pipe now performs the function of a "break tank" - excess fuel coming from the main tank drops back down to the auxiliary  - not out the breather

So even if I forget to turn off the auxiliary tank transfer pump or there is insufficient space for the auxiliary fuel, the extra fuel just goes back to the auxiliary tank - no waystage, no petrol stains Downy the fuselage, no pollution.

Simples!!

Posted (edited)

Just a comment on TurtlePack auxiliary/ferry tanks;

 

I have visited the factory, impressive quality control and testing (to destruction) of all products.

 

In my maturity (read decrepit old age) I find lifting 20 litres of fuel to be challenge. TurtlePack will make any size of bladder to order but I think the smallest standard  is 40 liters (Little Buddy) - way more than I would want to try and maneuver into my aircraft.

 

The solution would seem to be some form of "umbilical" fuel filling system ( which I believe TurlePack have for their larger systems but not for the Little Buddy ) that would allow placement of the empty bladder in the aircraft and then fueling in situ. The potential for spillage is a real concern, as is the safe stowing of the umbilical.

 

Don't get me wrong - I am seriously considering the purchase of a TutlePack Little Buddy 40 litre bladder - just need to work out the practicalities

Edited by skippydiesel
  • Like 1
Posted
2 hours ago, kiwiaviator said:

Another interesting idea Tasmag. As I think a non return valve would be required (to avoid this very thing in flight), a filling tap could be put in parallel with the NRV. The downside is an additional point of possible failure.

My thoughts were that you would open the inline tap, transfer fuel to the wing tanks, let the two wing tanks equalise and then transfer more if necessary. Once you are finished you close the inline tap and the wing tanks are completely independent of the Aux tank. Adding a one way valve would require the Aux tank to be filled externally instead of through the wing tanks. My idea was to use the Aux tank as soon as the wing tanks were low enough you accept the litreage held in the Aux tank. Once at your destination and on the ground open the inline tap and allow the remaining fuel to drain into the Aux and by the time you refill the wing tanks you would have a full Aux tank.

 

 

Posted (edited)

To get an idea of what is behind all the fibreglass and panels, especially around the fuel stuff,  take a good look at the vast J230 constructors manual, available on the website. If you've ever wondered what was behind various panels  etc, that is the way to find it. LOTS of photos.

 

Make sure your over wing tank vents (integrated with the caps of course)  are working as designed

- they have little ball cocks in them. 

 

There is a breather from the receiver tank back to one wing tank.  Think about various run dry scenarios of different combinations. I like the idea of check valve on the aux bladder, so you cannot have some dumb situation where your wing fuel drains into the bladder.... 

 

Be careful with your fuel pump wiring. arcs and sparks !

 

-glen

Edited by RFguy
Posted

Unless your 230 is 19 reg, you will have to get permission from Jabiru to alter anything from the LSA specification build

 

Ken

Posted
28 minutes ago, Kenlsa said:

Unless your 230 is 19 reg, you will have to get permission from Jabiru to alter anything from the LSA specification build

 

Ken

True!

 

19 The freedom (in part) to make minor enhancements to your aircraft.

Posted

When I built my aircraft I decided to install auxilliary wing tanks to supplement the 100 litre main fuselage mounted tank for long trips or the ability to get back from somewhere where fuel was unavailable. I put in a L/R/Off selector valve and a 4-6 PSI Facet fuel pump to pump the fuel via a T connector in the main fuel line where it feeds into the main tank and feeds the engine (before the filter and main electric fuel pump) at the same time. I did tests for how long it took to empty each 35 litre wing tank & also found that when the tank was empty the pump made a loud clatter which I can hear with the engine running. I do not have gauges in the wing tanks and while flying watch the main gauge going up while the auxilliary pump is on.

 

I usually run the aux for 10 minutes each side which will transfer about 1/2 of the fuel in each tank.

Posted

Rfguy, 

 

The plastic balls in the tank vents are no longer used on the 430, and as far as I know the the 230 either.

 

They were added to get the 160 certified was the advice I was given from the factory.

 

There should also be a vent from the header tank to both wings. The header tank should have 3 lines each side, two feeds and one vent.

 

The construction manuals are very good, but there are subtle differences and improvements that haven't been added over time.

 

Mike

 

 

Posted

Many years ago I needed extra fuel for a long trip. Not a jab, but what I did was carry a 20l container in the fuse with a fuel line from the fuel tank breather to the bottom of the container plus a vent line from the container to a vent point outside. That meant that at start up fuel was drawn from the container through the fuel tank and used. The vent to the container acted to vent the main tank when the fuel emptied from the container. It just needed a spevial cap for the container with the two fuel lines. It worked well with oniy a small amount of fuel left in the container.

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Posted
36 minutes ago, Yenn said:

Many years ago I needed extra fuel for a long trip. Not a jab, but what I did was carry a 20l container in the fuse with a fuel line from the fuel tank breather to the bottom of the container plus a vent line from the container to a vent point outside. That meant that at start up fuel was drawn from the container through the fuel tank and used. The vent to the container acted to vent the main tank when the fuel emptied from the container. It just needed a spevial cap for the container with the two fuel lines. It worked well with oniy a small amount of fuel left in the container.

KISS at its best - well done Yenn.

 

Not sure that I would be game to use your system - prefer to have a pump delivering the aux fuel to the main tank when I turn the switch on.

 

The beauty of a bladder (like the Turtle-Pack) is that no vent is needed - just have to have a transfer pump and of course the bladder can be folded away when empty, something a rigid entertainer cant do.

Posted (edited)
55 minutes ago, Yenn said:

Many years ago I needed extra fuel for a long trip. Not a jab, but what I did was carry a 20l container in the fuse with a fuel line from the fuel tank breather to the bottom of the container plus a vent line from the container to a vent point outside. That meant that at start up fuel was drawn from the container through the fuel tank and used. The vent to the container acted to vent the main tank when the fuel emptied from the container. It just needed a spevial cap for the container with the two fuel lines. It worked well with oniy a small amount of fuel left in the container.

Used on PPC Aerochute, I have used on seat beside me used as described by Yenn, worked a treat (same level as main tank). Fuel cap has 'O' ring so sealed system, if fuel cap not airtight would not work

 

Aux tank.jpg

Edited by Cosmick
Posted (edited)
5 hours ago, Tasmag said:

Rfguy, 

 

The plastic balls in the tank vents are no longer used on the 430, and as far as I know the the 230 either.

 

They were added to get the 160 certified was the advice I 

 

Hi Mike

Thanks for the info !   Owners need to verify their setups for their aircraft. 

I will see exactly what I have in mine- IE if the 2nd breather from the receiver  is hooked up. 

-glen.

 

Edited by RFguy
Posted (edited)

Hi Glen - have you figured out how to avoid excess fuel, from Aux, being vented overboard ?

Edited by skippydiesel
Posted
On 08/01/2021 at 6:36 PM, kiwiaviator said:

Has anyone installed a removeable auxiliary fuel tank in a Jabiru? I am looking at a Turtle-Pac Turtle Buddy or Big Buddy in particular. When I first considered it, I though "Great. It can plumb into the header tank!" Thinking more on it, it would be better from an operational point of view to transfer aux fuel into wing tanks as soon as room allows. That way, if there is a problem with the aux tank/pump, it will be picked up early allowing a Plan B to be put into action. Any thoughts/experience/suggestions/questions welcome.

I'm thinking you'd be better plumbing into the header tank and using the Aux tank first, that way if there is a problem with the Aux tank/pump, you still have the full wing tanks to get you somewhere.

  • Like 1
  • 1 year later...
Posted
On 9/1/2021 at 8:24 AM, Kenlsa said:

Unless your 230 is 19 reg, you will have to get permission from Jabiru to alter anything from the LSA specification build

 

Ken

If you used a Turtle Bladder?  It’s a portable installation, not a permanent mounted one? does this violate anything when fitted to a 24 reg aircraft? 

.

Posted
11 hours ago, jackc said:

If you used a Turtle Bladder?  It’s a portable installation, not a permanent mounted one? does this violate anything when fitted to a 24 reg aircraft? 

.

Just speculation ; Assuming the Turtle will be "plumbed" into the factory fuel reticulation system the answer  would be Yes to the "violation"

 

 

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