Fuel tank upgrade

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Includes: Highlander, Escapade, Summit and SuperSTOL.
z987k
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Re: Fuel tank upgrade

Post by z987k »

danerazz wrote:Just cap off the spars and fill them. Should be able to get about 11 gallons in all four spars (total).

Aaannnnd....comment!
I mean, I like the idea. Sounds like a leaky nightmare, but I like the thought.
Clark in AZ
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Re: Fuel tank upgrade

Post by Clark in AZ »

What a CG nightmare!
Building SuperSTOL Kit 512
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danerazz
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Re: Fuel tank upgrade

Post by danerazz »

Not really, about 36 lbs slightly aft and the same slightly forward

Now that I think about it, you could make tubes that slide in from the wingtip and fit in the cutouts in the ribs. If you did it before the wings were covered, you drill a hole in the outboard end of the wing tanks, install a connecting tube with a check valve so fuel only runs inboard from the tubes.

Then again, I forgot about the drag/anti-drag tubes...
Dane

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danerazz
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Re: Fuel tank upgrade

Post by danerazz »

External wing tanks that attach to strut brackets and have electric pumps

Wing tip tanks that are profiled to wing shape, and could attach by telescoping tubing that extends into spars (they would “plug-in” to the end of the wing)

Belly pod with electric pump


I’ll admit, the wet spar was sarcasm, but now I am seriously considering some of the other options...
Dane

Paralysis by analysis
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av8rps
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Re: Fuel tank upgrade

Post by av8rps »

I think there is an opportunity for someone here. Someone should build a auxialary, easily removable belly tank for the Highlander and Super STOL that can be installed as needed.

I have small tanks on my Highlander, and most of the time they are fine for what I do (fwiw, in 2007 we flew two Highlanders on amphibs from WI to Sun-N-Fun and back on the 9 gallon tanks, stopping every 3 hours for fuel). So one can certainly make them work. And frankly, I really don't want to add more weight to the plane when I really don't need it. And I really don't want to tear my wings apart to put bigger tanks in. But for the times I want to take more fuel it sure would be nice to attach my belly tank and gain another 10 to 15 gallons of fuel without carrying it around in bags or cans.

My vision says it would be molded fibreglass to closely conform to the fuselage shape so as to reduce drag, much like you might see on a Alaskan SuperCub, that is attached to the fuselage right at the CG. It would have a small fuel pump to either power direct to engine or to pump into header or wing tanks. It could even pump into a seperate header tank? But then again that would be more weight in the fuselage that would be there even when you didnt have the belly tank attached. Hmmm? But maybe that could be used for more fuel when you don't need that extra 10 to 15 gallons? A 4 or 5 gallon header tank by itself would help all of us with the small tanks since that's another hour of fuel typically.

I will probably add some bladders in my amphib floats with pumps, as it seems that when I fly on floats is when I want more fuel. Plus, amphibs typically move your cg way ahead, so I would place the bladder tanks in the floats behind the cg in an effort to offset the normal forward cg you get when going to amphibs.

There you go guys, there's the solution as well as the challenge to someone that has more time than I do to produce this.

Oh, and for someone not wanting or needing more fuel, the fuselage drop tank shell could be configured for more baggage area. Or maybe just to carry a gas bag or two, again, keeping all the weight on the cg.

I may have had a little too much coffee this morning... :wink:
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marl59
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Re: Fuel tank upgrade

Post by marl59 »

I built a removable aux tank set up using a Summit Racing 8 gallon oval track tank. I made a cradle with lift handles for easy removal. It sits directly behind the seats. I plumbed it into my fuel line upstream of the fuel pumps via a T fitting. It has an inline shutoff switch and a quick disconnect that seals at both ends when disconnected. The tank comes with a port to install a vent. So on a long trip I burn it out first then switch to my wing tanks. It works great. I recently flew from Central California to Central Idaho with only one fuel stop. I have a Bonanza with 4 separate tanks so I'm used to fuel management with multiple tanks. When I'm flying local I remove the aux tank and run the wing tanks. The Aux tank when full moves the CG aft a little bit but doesn't affect the flight characteristics much at all. If anyone asks I can post pics. The whole thing cost me less than $300 including the AN fittings.
Clark in AZ
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Re: Fuel tank upgrade

Post by Clark in AZ »

marl59 wrote:... If anyone asks I can post pics. The whole thing cost me less than $300 including the AN fittings.
YES! I would love to see some pics.

Thanks,
Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
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marl59
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Re: Fuel tank upgrade

Post by marl59 »

Hi Clark,
Here are some photos of the tank.
You do not have the required permissions to view the files attached to this post.
Clark in AZ
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Re: Fuel tank upgrade

Post by Clark in AZ »

Cool! Thanks for posting!

Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
av8rps
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Re: Fuel tank upgrade

Post by av8rps »

Could I impose on you to show us a pic or two of how it fits in the aircraft?
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marl59
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Re: Fuel tank upgrade

Post by marl59 »

Sure,
I reinstalled it Saturday for the High Sierra Fly-in. I'll take some photos after work today.
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marl59
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Re: Fuel tank upgrade

Post by marl59 »

Sorry, I'll have to take the time to convert the files to JPEGs. This site does'nt allow HEIC files.
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BDA
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Re: Fuel tank upgrade

Post by BDA »

How much does it affect the weight on the tail wheel in that location?

Does tail feel really heavy?
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
Doc_dyer
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Re: Fuel tank upgrade

Post by Doc_dyer »

why the aluminum cover? why would one need to gain access more than fiberglass tanks ?

how does the leading edge of metal cover attach ?

is there a low point drain to remove water ?

why did you plug front fuel access point? could one tie front and rear together in a T to prevent fuel starvation on decents? or run two lines to header tank, one for rear and one for front. Level flight low on fuel front would transform to vent line.

if one didn't receive the roll of rubber for tank mount, where could one find that.

Thanks in advance.
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danerazz
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Re: Fuel tank upgrade

Post by danerazz »

No, tying front and rear ports together will not help on a descent. You would have to run the rear lines behind the doors, the front lines IN FRONT OF THE DOORS, and then combine them at a common low point, preferably at a vented collector tank of some kind. Just putting front ports in and running a line back to the rear port is the same as not having a front port.

The second line to the front as a vent plan DOES have merits, but a high dedicated vent point makes more sense.
Dane

Paralysis by analysis
#242
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