S1 Fuel Tank Setup

[dickf]

Hi Guys

My S1 has a main tank and an aux tank mounted just below and to the rear of the main tank. The main tank hold about 7 gallons and the aux about 3. This setup is dictated by a cross-member that runs below the aft portion of the main tank and above the aux tank. I don't know if this is a common S1 arrangement.

The main fuel line exits the bottom of the main tank and runs to the gascolator where it can be sumped. The rear tank has a line that runs from the rear of the side of the aux tank, up hill, to the front of the main tank. This means that when the bird is on the ground (tailwheel), some fuel is trapped in the rear tank. In flight, this will move forward to the main tank, no problem. What concerns me is the water that may form in the rear tank and cannot be sumped on the ground. I suppose it would manifest itself after climb out and level-off. Not an ideal time.

Does anyone else have this arrangement and concern?

TIA,

Dick Frederick

 

[Schmleff]

I used to have almost the same setup, but I had a valve between the two tanks so that I could shut it off during takeoff and landing. I later change the setup to have its own line to the tank selector valve. The valve between the two tanks is only used to crossflow fuel from the main to the aux during fueling.

I never had issues with water being trapped in it.

 

[dickf]

Thanks for the reply, Jeff.

I must say, I never recall getting any water when I sump the main tank of my Sonerai (not that I have flown it much yet. I bothers me, though, that I can't sump the aux tank.

Perhaps the simplest solution is to put some sort of gascolator on the line that feeds the main tank and rig up a method of sumping that.

Dick