Foolproof tank installation.

[Samuel117]

Hi every one, I have to admit before hand that I read the previous sections about belly tank installationand for that I thank you all.My problem, I have zero experience and need to install a belly tank to my drifter. I need all the info I could find. This are my questions:

 

1- what do you use to attach the metal strips that holds the tank to the belly? Bolts?, rivets?

 

2- my tank has two fuel connections on the back and a draining and one on the front on top,close to the filling cap. The lower one goes to the engine. The upper on the back should bring fuel from the upper tank?

 

3- the one on the front on top is the breather?

 

4- I have no clue if my tank has a low fuel warning device but it came with the green and red lights on the box. Note this is an used tank. Actually looks pretty old to me. I have no clue how the wiring should be made.

 

5- by now you know who is the fool on this post but still, I need help.

 

Any diagram or article or any advise on how to test the tanks for leaks will be appreciated. Before asking I have tried to find any info about this but I could not find anything on this. By now and thanks to your early posts I will use the top tank to gravity feed the lower one. If anybody has any data on this I would appreciate if you could email me any time. My email [email protected]

 

 

 

 

[M61A1]

The factory setup is that the top tank is plumbed to the top fitting at the back of the belly tank, the lower belly tank fitting is plumbed to the electric fuel pump, the one up near the belly tank filler runs along the tank and is connected to the vent line on the rear top face of the top tank. I cant see if your tank has the low fuel sender , you will see it on the left side of Tex's tank.

 

. If you go to page 1 of the "Drifter Pics", Tex has posted a very clear pic of the installation, but you will note that the lower fuel supply line seems to disappear for a bit, that is because that model is required to have a fuel shutoff valve, and it is usually located on the r/h side of the fuselage pan.

 

The retainer straps are made from large worm drive clamps and are attached to the fuselage with screws into Rivnuts or Nutserts that are permanently installed on the pan. There has been much discussion about the best way to plumb these tanks, it will come down to personal choice, as the fault with the factory setup is that if you should accidentally puncture the belly tank on takeoff, you will lose all your fuel, but that will only generally occur if you operate from rough strips, which many of use do out here.

 

The other way to plumb it is to have your engine lift pump drawing from the top tank and the electric feeding the top tank from the belly as required, this eliminates the likelihood of losing all you fuel, but requires good fuel management.

 

 

[Samuel117]

M61A1, Thank you very much. Your comments cleared up my questions. My tank does not have a sender to let me know about fuel level. Actually my main tank does not let me see the level of the fuel lower than middle upper part of the tank. That already is a concern to me. At this point if I add the belly tank still leaves me only with the approximate calculation based on flight time. Unless you fill up the upper tank you won't be able to say how much fuel you have left. An alternate route will be to fit a couple of clear fuel tanks often used in US for the super Drifter currently in production. This has the advantage of two clear tanks with a simpler fuel system but will decrease the allowed weight on the backseat due to CG constraint. I hope they will bring some kind of fuel level warning. it is almost impossible to see from the front seat. The use of a mirror could be an option. The use and installation of the two US tanks will add considerable expending and time to the equation. Let me go back to the drawing board and see what I come up with. Thank you again.

 

 

[M61A1]

Have a close look at the left side of your top tank, they normally have a strip that that runs top to bottom that isn't gel coated, if has been repainted, you may be able to sand it off to reveal the sight gauge. I calibrated mine the time consuming way, adding a liter at a time, then markings I on the side. Be wary, of installing your belly tank with the 912 fitted, I had a drifter fitted with a 80hp Verner(74kg installed weight), I installed the belly tank after buying it , some years ago the extra weight didn't go too well, and seemed to add to aft CoG feeling.

 

 

[Samuel117]

The CG was likely the main reason why the previous owner did not installed the belly tank. My main tank has the strip but for some reason the lower half of the strip it is so dark it does not show the fuel level. About the CG people seem to disregard the importance staying within the approved limits. I remember once getting a ride on a Maxair Drifter 503 Xp. The pilot was about 200 and I was 220. Full fuel with. 14 gallons on two tanks behind the passenger and the airplane did not seem to notice it. I got so scare some time later when I found out about the weight limit of the rear passenger being about 180 pounds. Right now there is a super Drifter being sold at Barnstormers.com and the owner claims to have had a 250 pounds passenger with no problem. In my experience with RC airplanes as you move the CG back the airplanes gets more agile up to a point in which get so out of control that it is impossible to recover. Any stories about CG issues in the Drifter's history?