2nd Gen Non-Engine/Transmission Route return fuel to aux tank for cooler fuel, what do you think?

[rweis]

I am adding a 55 gallon aluminum aux tank to the bed of the truck.



I route VP44 return fuel to the OEM tank vent line now. I route RASP return fuel to the OEM tank vent line now. All in an effort to mix the fuel and additives better, constantly refiltering the fuel with a RACOR 690T, keep the fuel input to the VP44 as cool as possible to keep the VP44 as cool and as functional as possible.



Do you think that if I route all return fuel to the aluminum aux tank it will help keep the fuel cooler?, or will sun exposure of the aux tank tend to heat the fuel?



Then the fuel will flow from the aux tank to the OEM tank constantly if any / all fuel is routed to the aux tank first.



Bob Weis

 

[SnoKing]

In the marine environment people run into issues all the time switching the return line wrong and overflowing one of the tanks(draw from one and return to the other). So, be sure that you do not create that issue for yourself. SNOKING

 

[EKlem]

That is getting pretty complicated to add another tank. If anything should go wrong in transfering fuel from the bed tank to the oem tank, you will run out of fuel real fast and possibly overflow the bed tank. I would stay away from doing for the simple reason of reliability.



It seems to me like it would be easier to put a fuel cooler in the return line.

 

[rweis]

I do have (4) fuel coolers in the return line, and they work very well (I personally think EVERYONE should have 2 or 3 return fuel coolers (northern guys would have a cooler bypass for the cold months). I have made it a several year study to know exactely what temperatures the VP44 fuel input and fuel output are.



I am adding the bed tank (55 gallons) to extend towing range (I figuer on 10 mpg) and was just tossing out an idea to get some feedback. This summer I am going through some pretty rural parts of the south, not on the Interstate, and I don't want to have to "go find fuel". A local manufacturer made the tank for me and it is exactely what I wanted. The on-line tank products were a little bit not quite what I had in mind in dimensions and had bells and whistles I did not necessarily need.



SNOKING had a good point about if you do not know how much fuel you are using vs how much you are returning you could get yourself fairly screwed up. I do not have a simple clear way to know exactely what the amount of return fuel vs the amount of used fuel is, so I probably will just use the bed tank as an aux tank and run the system as I normally do, and refuel the OEM as needed.



There may be some small benefit of adding cooler fuel from the aux tank to the OEM tank occassionally, but that should be a pretty minimal difference.



Thanks for the inputs. I'll just KISS on this one.



Bob Weis

 

[Boondocker]

I don't think it matters much which tank you return to, depending on your aux to main tank equalization program.



Let's assume for the sake of discussion that your aux fuel is cooler than your main fuel because you are returning hot fuel to the main tank.



Scenario 1: In this case, I'm transfering cooler aux fuel to my main tank, thus cooling the main fuel.

Scenario 2: If instead you were returning to the aux tank, you would warming that fuel, then when you transfer, you warm the main fuel. 6 of one, half dozen of the other?



In my case, I have a Transfer Flow 50 gallon tank, which uses their Trax II equalization program. Both tanks have senders to gauge their fuel levels. The equalization program automatically runs the pump to keep aux and main tanks relatively even, ie. both full, both 3/4, both 1/2... you get the picture. Even though hot fuel returns to my main tank, it's constantly being "diluted" with cooler fuel. All in all, it's kind of a side benefit of fuel cooling because of the aux tank



Neil

 

[rweis]

I just thought that because the aux tank is metal instead of the composite OEM material that the heat would be radiated more easily. Probably does not really make as much a difference as I first thought it might though.



The constant "remixing" of the OEM with the aux mix might bring it down a couple of degrees though. Every little bit hekps. Actually the aux remixing might help stabilize the OEM at a lower temperature than it would otherwise be.



Thanks for the input,



Bob Weis