How much fuel returns?

[RedRamer]

I'm looking at puttin in a fuel tank in the box.

Does anyone know how much fuel goes back to the tank in return line vs how much is sent forward?

I'm thinking if it not much, then maybe I can just tap into the fuel supply line and let the return go back to stock tank.

But if it lots, then my 80 gals box tank might overfill the stock tank.

thanks

 

[Blakers]

I would think at idle, more than 99% of the fuel is returning to the tank. What you need is a diverter valve that has a suction and return line for each tank - I think it is a 6-way valve. Available from an RV dealer.



Blake

 

[JJW_ND]

Have extra tank feed main!

Based on my experiece I would just plumb the extra tank to gravity feed into the vent (filler vent) line. You can put a solinoid valve (Napa for a older chevy duel tank) inline which will allow you to control this from the cab.



NO PUMPS!



NO EXTRA FILTERS!



SIMPLE!



We are using this in several truck here with no problems. I have had one in my 96 since new which was in a 94 truck previously. It has transferred at least 8000 gallons in my 96 alone. Works summer and winter.



It does not flow real fast w/o a pump, but then if you forget to watch your main fuel gauge, it will not over flow as nothing is pushing it. It does flow enough to keep a head of 8 mpg fuel consuption.



We build our tanks and design the intake to suck directly off the bottom. We have never added any filters and never had a rust or water problem (all tanks are steel). All fuel is still filtered by the main filter. Our axillary tanks are 50 - 60 gallons made out of 1/8" steel treadplate.



jjw

ND

 

[rhoads]

In general 3/4 of the fuel pumped by a cummins is returned to the fuel tank.

You could use the above post routing But be advised it is not D. O. T legal. If some one is installing it for you and charging you there butt is hanging in the wind. If you do it your self same.

However you can tee in to the filler neck ,install a elect punp,tee in to the rubber by-pass tube ,watch your in dash gauge gauage ,shut off the pump,stop turn off manual shut off valve,put still not D. O. T. legal.

In a crash this is not a veh you may want to be in however there are thousands out there rig'ed this way.

the proplem with electric switching valves are they FAIL... ... .

best way buy the old manual control valves drill a hole in the floor board and tee in to the suction and return hoses. . cheap and dot legal with use of elect transfer pump.