fuel tank question

[Destroyer]

Originally Posted by reelapeelin

when I first set my 74 up w/two 40 gal tanks, I tried and tried to make it work...never did, so I put individual shut-offs on each line and controlled them manually...run off one tank goin out, the other comin' back...

I got a buddy w/aSkeeter bass boat...has twin tanks and draws them down evenly from a single line...how it does it, I ain't figured out yet...

You know... actually, there IS a way to make it work.. It's one of those simple things that stare you in the face and it's so easy you don't see it...

The answer is simply to cross connect them... plumb the bottom of tank one over to the bottom of tank two. Then, on a second line, plumb tank two to the engine. Do not connect the line running from tank one to tank two with the line running to the engine.

Gas, like water, will always seek it's own level. So, since both tanks are connected together at the bottom, and as long as both tanks are vented so atmospheric pressure is the same inside each tank, and both tanks are sitting at about the same height inside the hull, what will happen is that as tank two is drawn down tank one will replenish it in an effort to stay level with it. The result will be both tanks will be drawn down at the same time!!!