kmac425

My Feedback: (82)

Hi all,

Just curious on the various methods RC'ers use to set up their fuel tanks?

How long does your fuel line need to be in the tank? Should the clunk be 2/3rds of the way down, half way down? Right now I'm set up with a filler line with a long line and clunk so I can not only fuel but unfuel the entire contents of the tank. For the pressure line I just have brass rod bent towards the top of the tank. Is that correct? Also, what type of fuel line do I use for the inside of the tank? The thick stuff of the thinner more flexible stuff? I would think the thinner stuff, right? Or does it kink alot easier?

My main question is concerning how long to make the actual fuel/carb line set into the tank. I want all the available fuel that I can get, it seems like common sense but do I want the line short enough so that it will rotate all the way when the tank is pointed straight down? What setup will yeild the maximum flying time without comprimising fuel starvation?

Thanks for your input,

kmac

DavidAgar

My Feedback: (108)

I typically try and get the fuel pick up clunk as close to the back of the tank as possible without the clunk hitting the back of the tank. The fuel line needs to be flexable so as to flex to the top of the tank when the plane goes inverted. Not sure that is the golden word, but it is how I do it. Good Luck, Dave

JohnBuckner

My Feedback: (1)

Dittos to what DavidAgar has said.

This line did bother me thought that you said and not sure but may have misread. That sounds like you want the clunk to fall forward to the front of the tank when the airplane is on a down line.

If so then you do not want this to occur as it will pinch off the fuel supply. This is a common problem after hard landings and often causes lots of problems if it goes undiagnosed. The clunk should stay at the back of the tank at all times and be able to reach four corners without ever touching the back wall. Usually an eighth inch or so will do it. After you assemble the tank always hold it up to light with the back straight down and confirm the clunk will freely reach the four corners without ever touching the back wall. Too much here is preferable to too little clearance or short runs can become a problem.

John

TedMo

Both replies that I just read to you are 100% fact. The only things that I might add are. You mentioned having a brass line to top of tank, again correct but try to bend it so that it is as far to top front as possible. I have found I like to use the colored lines that are now available. Red for supply, green for pressure. clear for fill. By the way you do not need three lines if motor isn't cowled and you have easy access to fuel supply line for filling and emptying. Also if using 3 lines be sure to plug fill line after filling. I use short pc. of 1/8 inch dowel. One more thing. Many have mentioned foam around tank. No problem with that if sufficient space. I usually only put foam when needed to hold tank firmly in place
This is a complaint I have not for you but for tank makers maybe someone can foreward this to them. Too many tanks are made that can NOT be seen thru to be able to see the lines inside. This hasn't always been s o, why now?

Lots of luck and good landings

kmac425

My Feedback: (82)

Thanks everyone, that makes sense. It'll be in a new showtime 50, so the 3 line setup is what I'm doing.

FrankFuss

I read that some of the pattern guys are using Sullivan 1/2A Fuel Tubing in the tank. This tubing is flexible enough to allow the clunk to move anywhere in the tank, front or back, and not cut off fuel flow. I setup my Showtime 50 this way, using a Dubro 14 oz tank, and have not had any problems.

Frank

jaka

Hi!
Fuel lines should not be able to bend forward!!!
Never! You must have heard wrong!
Tettra "Bubbleless! tanks are the best tanks...second best is an ordinary tank set-up with Uni-flow (Two clunks) !

FrankFuss

Well, I am no expert, but Troy Newman is. You can read what he has to say about it.

http://www.rcuniverse.com/forum/fb.asp?m=7190459

...
So in a conversation with Jason Krause one of the top heli guys in the world. We started talking about engines and the fuel tanks. His clunk was looking like it was stuck up front of the tank. He picked up the heli and the line was so flexible that it would go anywhere in the tank. SO I said to myself....this is what we need in the pattern plane setup. So I started using the really flexible fuel tubing like Sullivan 1/2 A tubing for the pickup tube in the tank on the YS 160 and 170DZ engines. Its so flexible that the foam clunk will immediately drop to every corner of the tank if needed. It absolutely stays in the fuel anywhere the fuel may go. The monkey see folks discount the 1/2A tubing as its too small of diameter...but the flexible stuff from Sullivan is perfect and the diameter of the inside is more than sufficient for the 170DZ
...
SO thats the straight skinny. Ideas evolve and sometimes are picked up by people that think they know better. By the way many of the top pilots are doing the very flexible line thing in their tanks. Some of them probably never tried the header tank, and some figured it out on their own or with some conversations. I know Quique at first was running a header tank in his Bipe last year. This was a result of him flying electric for a couple years and not being in tune with latest ideas on the YS DZ engines. After seeing the results that I saw he switched to the very flexible line as well. I have also noticed this is what the Japanese pilots do and perhaps have done all along.
...

JohnBuckner

My Feedback: (1)

Prather half A on top and Great Plains medium on the bottom:

The original poster is obviously on a first or second airplane and having trouble figuring out how to assemble a basic tank and you are suggesting this?

Kmac I highy suggest you assemble the tank as intended or you are gonna have Probs!

Gray Beard

My Feedback: (-1)

John, whatever it is you are holding the lines with sure looks like the smokers lung I saw this week at the BODY show in town!! Really!!!
JAKA, Ford makes the best car!!

The Ghost

kmac, A couple of photos so you can see the tank setups (Thank RCKen for the Photos)
Set the third line(fill/drain) up as shown so the tank can be drained.

Cheers