Auxiliary Fuel Tank
|Best Place to buy:||If you are LUCKY you can find one on ebay|
|Cost to Have it done in a shop:||$??|
|Special tools needed:||None|
Take out everything in your trunk
Take out the Fuel Tank
Clean it out
While you are at it... Replace Fuel Strainer
Go to local hardware store and get some of these:
Drill into your fuel tank, one hole at the bottom, and one hole at the top like so:
Use some JB Weld or equivalent and place the brass inlets into the tank, make sure they are in there securely with JB weld. Make sure the stuff dries for a good few hours.
Then connect (a) to the top
and (B) to the bottom, and bolt the new tank to the floor and you now have a gravity fed tank. If you are going to use Biodiesel use some polyuatahne tubing NOT fuel line hose. That stuff WILL degrade in less than 1 week using biodiesel. (B100) I know this by experience... ahem.
I will polish up this guide later.
Certainly there are a number of ways to do this, but the simplest to me seems like it'd be to run a couple of (fairly fat) lines, one from the top of the spare tank into the top of the main tank, and one from bottom to bottom. Then the "spare" tank would fill up and drain along with the "main" tank, and your fuel gauge would still work. This is more of a parallel setup than a serial one, though, I don't know how you could do a serial connection and have the fuel gauge work unless you set it up to drain the secondary tank first and just lived with the fact that the fuel gauge stays on 'full' for the first 2/3 of your fill.
It might be easier to do what dual-tank trucks do (at least the ones with which I'm familiar), although it'd require a bit of electrical knowhow. This Ford van that I used to have had two tanks and a switch under the dash to switch between them. The switch then would use the level sender from the selected tank and turn on that tank's fuel pump (I guess, never really worried about it too much since it Just Worked). Ahh those were the days, when $50 at the pump actually got you a huge load of fuel.
there are several ways how a secondary tank can be plumbed in (line or parallel), depending on whether you want to run vegetable oil (which will require another filter unit and heater) or plain Diesel, whether dino or bio. I mounted this tank using a single piece of aluminum band, bolted to the left side, wrapping around the front, and then bolting to the right side of the trunk panel (back of the rear seat). You can get this stuff at any local builder's depot or metal shop. Fairly easy installation, with just 4 90 degree bends and 2 bolts, 4 washers, and 2 nuts.
This tank has one threaded inlet port and one treaded outlet port. If you just run Biodiesel, all you need to do is get those lines to the front of the car and merge them with T-pieces to the existing fuel lines. You will also have to install one electric fuel pump [aftermarket, such as Carter will work just fine for anything but common rail Diesels] to move the fuel, and one switch on or below the dash were you chose between tank 1 or tank 2. Pretty simple. This aux. tank doesn't have a fuel gauge, so there's no indication for the level of fuel other than looking through the filler cap once in a while (some people use a measuring stick, just like it's done on some race cars).
If you plan on running WVO, as I do, you most likely want to buy a heated filter unit that's mounted in the engine compartment. All this stuff is readily available, and, again, there are many ways to make it work. For example, some guys even run the heated coolant or exaust alongside the tank to always assure heated fuel.