Thread: Diesel fuel surge tank

Option 3: Get a weighted pickup such as those used in boat fuel tanks and install it at the end of your stock pickup in your tank. The end of the pickup is weighted with lead, and rolls to the lowest end of the tank, where the fuel just so happens to flow to The reason I suggest it is that it is something that I am about to do in my own auxiliary tank

Tank has horizontal baffles, fuel runs past baffles and away from pickup... a moving pickup I am sure wont get past the baffles? Thanks for idea though!

S

Can't you just pump out the flat aux tank and run permanently off the main tank? A facet pump is all you need. Just transfer fuel when you need it.

draw out the schematic of the fuel tank but ID suggest that you just do away with the change over valve and install a facet pump .

cut the return line from the engine and T piece the output of the facet pump onto that to fill the main tank from the aux tank and then t piece the breather of the main tank and link that to the return line of the aux tank. This prevents the main tank from over pressurising, the aux tank from vac locking and if you happen to try to overfill the main tank it will just flow back to the aux tank.

Then youve got a substantial surge tank in the form of your main fuel tank.

If I wanted to run effectively one big tank I could easily gravity feed the aux tank into the main (it sits above it)...

Fuel can be pretty crap up this way. I like having two seperate tanks.
When travelling up north I only fill one of the tanks at any one stop... still have some range if I get a tank full of water.


Schematic is tricky... how about flow diagram!


Alloy tank-----------water seperator---------------
/
/
main tank ------ water seperator ------------Pollack -------------donk

The tank measures approx 1300mm by 500mm and is 150mm deep, pickup is a barbed fitting at the back of the tank, fuel line then runs across to a stock water seperator adjacent to the original seperator before feeding the Pollack. Pollack has independent feed and returns depending on which tank is selected.

Im guessing I may just have to cope with the issue

Steve

Stoopid editing. those forward slashes are supposed to link the top water seperator line to the Pollack!

So much for a line diagram.

S

Originally Posted by roverrescue

Tank has horizontal baffles, fuel runs past baffles and away from pickup... a moving pickup I am sure wont get past the baffles? Thanks for idea though!

S

No worries - I guess there are advantages to my tank not having baffles after all

The original setup that I had was exactly as Blknight.aus and bee utey described - a facet pump under the drivers seat pumped fuel from my aux tank to the main tank when the main tank was empty. It's by far the easiest solution to the problem you describe, and for me it worked perfectly. Though if you are using a pollack valve, I am wondering if you are setting your truck up for SVO, or an alternate fuel - they seem to be the valve of choice for SVO enthusiasts.

If for this reason, the transfer pump solution is not feasible for you and you do need to make a surge tank, then it's pretty straightforward. It's nothing more than a mini fuel tank, and can be made from any suitable container -last one I made was from an old fire extinguisher. You'll still need to buy a facet pump - it will pump from the pickup of your main tank to the input of the surge tank. Plumb the return line of the main tank to the return from the surge tank. Mechanical fuel pump on the engine now gets plumbed to the pickup of the surge tank, and return from the IP gets plumbed back to the surge tank.

Google gives me a diagram of more or less the same setup as used by the ricer boys, but you get the idea.

making the surge tank to do what you want (contaminated fuel is a valid concern and the best arguement for the pollak valve setup)

to do it simply make up another tank with 4 outlets, 3 that goto the top of the tank and one that draws from the bottom or near the bottom with a drain bung.

and we go

from the aux tank pickup, through a strainer, into a facet pump, into a combo fuel water seperator/filter (30 micron preferably) and into one of the 3 top ports of the "surge tank"

from another of the 3 top ports on the tank we go back to the aux tank

the last of the top ports is the return line from the pollak valve(if you use some clever work on orifi size and port orientation you can do the last 2 on just 1 port this will also give you an electrical self priming of the fuel system once the surge tank is full)

the bottom port is the supply to the pollack valve.

what you are talking about doing is the exact same as what Ive done with fozzy but in my case you substitute the words aux tank with WVO tank, surge tank with fuel heater and pollak valve with "bloody expensive hydraulic valves"

IF you like I can pretty much sketch up exactly what you want off of the top of my head. (in both physical layout and hydraulic schematic format) or you can just check http://www.aulro.com/afvb/803855-post15.html this link and replace my 2 individual 3 port valves with the pollak 6 port valve suitabley plumbed.