Topic: is this math right? fuel cell calculations

[Ramrod]

so im contemplating building a fuel cell, some website said there is 231 cubic inches per gallon.  so does that mean a 35" x 24" x 6" cell would fit 21.8 gallons?  doesnt seem right thats a lot of gas.

[DTB]

Well according to my calcs.....

35 x 24 x 6 = 5040 cubic inches / 231 = 21.81.....

Thats a big tank....its almost 3 feet long

[BLACKDOG]

  Thats what I got too! 

Looks like its right.

[weirdtimes_7]

Why such a big tank?

military_stang

[Hammerhead]

Yep, sounds right...  21.818181..........

Why such a big tank?

That's not so big.  I'm building one for my FJ40 with a goal of over 30 gallons...

[emsvitil]

If you can get it to 7", you'll have 25.45 gallons..........

[Ramrod [OP]]

thats the size tank i could fit under the bed of my truck behind the rear axle without it hanging below the frame, i actually will probably make it smaller just because i dont need that much gas

[93tonkatoy]

The reason stock tanks look like they will hold more than you can put in them is because of temperature expansion. They allow extra volume so that when the fuel expands as it warms and evaporates, it has room. If you don't allow for this, the fuel will find somewhere to go. carb, charcoal cannister, out the cap (the non sealed ones), or could possibly push a return line off somewhere. 10% of the volume should be more than plenty. and remember a vent line (from the highest point in the tank) to gather and route the vapors to the charcoal cannister.