Sumping a stock fuel tank

[RedHeartbeat]

Sumping a stock fuel tank


Have you ever had a fuel starvation problem during hard launches? The OBS trucks are notorious for this issue. Here is the solution, a rear mounted fuel tank sump. Below is a list of all parts used. SummitRacing.com was sourced for all parts.

I use 1" x 1/8" flat bar to make the mount for the pump and filter. To isolate pump noise I wrapped the clamped pump and filter with an old 10-speed tire tube.

This list includes all items for a return style fuel rail.

1/2 NPT dual outlet sump CEE-4041

Hose purchased for RCSB
-6AN = 3/8" inside diameter (20 feet) SUM-230620
-8AN = 1/2" inside diameter (6 feet) SUM-230806
1/2" INSULATED CLAMP 10PACK SUM-G1882

outlet side:
1/2 NPT male to -8AN male outlet fitting SUM-220847
-8AN female x 90 degree hose fitting SUM-220887
-8AN hose
-8AN female to -8AN hose straight fitting SUM-220890
-8AN male to 18mm x 1.5mm male fitting AER-FBM2244
Bosch 044 pump held to the frame by 2.5" Tbolt hose clamp (2) SME-240250 (clamp)
Weber carb 12mm x 1.5mm male x -6AN male adapater EAR-991944ERL
-6AN female to -8AN female straight swivel EAR-915186ERL
-8AN Summit fuel filter held to the frame by 1.5" Tbolt hose clamp SME-240175
-8AN female to -6AN male reducer EAR-9892086ERL
-6AN female to -6AN hose fitting SUM-220690
-6AN hose
-6AN female to -6AN hose fitting SUM-220690
-6AN female to -6AN male gauge adapter swivel fitting (optional) R-100199ERL
-6AN male to 3/8 ID Russell fuel line adapter 640850

return side:
1/2 NPT male to -6AN male outlet fitting EAR-981668ERL
-6AN female x 90 degree hose fitting SUM-220687
-6AN hose
-6AN female to -6AN hose fitting SUM-220690
-6AN male to 5/16 ID Russell fuel line adapter 640860

The sump will need to be welded to the rear floor of the fuel tank. This will require removal of the fuel tank and plastic liner on the OBS trucks. Do not attempt to weld this in yourself, take the empty fuel tank and sump to a radiator shop that can cut and weld it with a shielding gas filling the tank to prevent the risk of explosion from the gasoline vapors.

Remove the factory fuel pump from the OBS pump assembly and close off the fuel pump supply and return tubing by welding or flatten it and bend it over on itself. You can also remove the supply and return fittings on the top of the fuel pump assembly. Take some JB Weld and fill in the holes. Cut and remove the wires that went to the old pump. All that should be left is the vapor vent tube going to the filler neck and possibly the fuel vapor line if you decided to keep it, I close it off.

When you assemble the tank you will need to cut an area from the plastic liner to clear the sump. The parts above are listed in order of assembly going from the fuel tank towards the fuel rail. If you're worried about keeping the aluminum fittings pretty, be sure you buy AN fitting wrenches.

[MikeGyver]

Nice. At one time I was thinking of making a metal tank so I could do the same. Your long list of fittings looks expensive. This is another thread that needs to be included in the price list when a newbie asks "How much will (xxx) HP cost?".

[Defunct SO]

This tank was also coated inside. It will prevent the sump from rusting and ensure a long life. Select radiator shops can coat the inside of the tank after its sumped.

[r.barn]

Tip: Aeroquips "socketless" hose is NHRA rated, cheaper and easier to
work with than braided stainless. Hose ends are just push a barb'd fitting and put small
hose clamp on for little extra security. ( but not too tight)

If you've ever wrestled with getting hose ends on stainless hose you'll love
this stuff.

Comes in blue and black.

[RedHeartbeat]

Yeah, that stuff is nice but the price was about the same when I did this one. You still have to buy the same number of connectors and the hose wasn't any cheaper. Its a lot more flexible for sure. This was my first braided line setup and I had no problems assembling everything in my home garage. My only complaint is the stainless likes to stab you when you're assembling the ends. I used an abrasive cutoff wheel to cut the hose to length.

[Tig]

Looks good, nice install.
Pretty creative using 10 speed tire tube.

[knute_gis]

Why didn't you run -8AN all the way to the fuel rail?

I'm wanting to do the same thing but with a fuel cell and the socketless hose mentioned above.

I'm thinking of using a Walbro 255 but I think the hose barb fittings included are 5/16. Would this pump be a bottle neck or should I just replace the 5/16 fittings with 3/8 fittings?

I'll post pics of my setup when I get it finished.

thanks, Kris

[LS1GMCTruck]

Why didn't you run -8AN all the way to the fuel rail?

I'm wanting to do the same thing but with a fuel cell and the socketless hose mentioned above.

I'm thinking of using a Walbro 255 but I think the hose barb fittings included are 5/16. Would this pump be a bottle neck or should I just replace the 5/16 fittings with 3/8 fittings?

I'll post pics of my setup when I get it finished.

thanks, Kris

-6(3/8") fuel supply line is more than sufficient for over 600 h.p.

[usabodyguard]

good write up... Im doing something similar, just a little more extreme...

here is my custom surge tank... my main tank will fill this one. This will house an aeromotive eliminator and an aermotive fuel filter. -8 and -10 lines in and out of this.

[RedHeartbeat]

Keep us updated on the install.