OBS 7.3 fuel system plumbing

[V-Ref]

Can someone spoon feed me a link to how this system is plumbed between the two tanks?

A response like would be really helpful:
Stock tank->mech fuel pump->filter assembly->motor->pressure return spring->tank...or please correct above....

Has anyone tried sumping the two tanks together to get rid of the selector valve?

When I had my first OBS, it was just a tuned stocker...so didn't mess with the fuel system..this one looking to do a bit more.

Thanks in advance.

 

[SPEEDDEMON31176]

Well assuming you know that each tanks lines go to the selector valve and then to the engine bay is a start. From there the feed line goes to the two stage mechanical pump. It then gets pumped into the fuel bowl where the fuel is filtered, then the second stage of the pump pressurizes the fuel and sends it out to the ports at the rear of the engine. The fuel is then used by each injector as needed. Excess fuel then comes back out of the engine at the front ports in the heads and into the fuel pressure regulator. From there the fuel is sent back to the selector valve and the corresponding fuel tank.

 

[V-Ref]

SpeedDemon

I was hoping a fella like you would come along and make a post like you did.

Thanks!

Just to regurgitate to ensure I've got it right:

selected tank->selector valve (supply side)->1st stage of mechanical cam driven pump->fuel bowl->2nd stage of mechanical cam driven pump->rear ports of engine heads->injectors/internal fuel "rails" in head->front ports of engine heads->fuel pressure regulator->selector valve (return side)->selected tank

 

[Tom S]

Tanks tied together can result in over filling when parked on steep slopes.

 

[FrankTheTank]

Could always run 2 selector valves in paralell with each other. Also there must be a way to tie the two together as thats how chevys do it, unless the selector valve is computer contolled??

Or have a small pump to pump fuel into the other tank when its low?? Just throwin ideas out

 

[Nodge]

The stock selector valve will support some pretty serious set ups.

 

[bigbeanOBS]

beans makes a system to hookup to the lines coming out of the selector valve and you got the option of two pumps or one i have the two and it gets the job done

 

[LA_Stroker]

And I have the one. Work perfectly well with my 160/100's.

 

[davey99ps]

I know you asked how to make both tanks work, but another option is to get a 38gal bronco tank for the rear an ditch the front tank. That's the route I went, I deleted all the dual tank stuff, added a sump an did my own fuel system. It works great, an with 38gal of fuel I can still go well over 600mi between full-ups

 

[bluedge8]

I know you asked how to make both tanks work, but another option is to get a 38gal bronco tank for the rear an ditch the front tank. That's the route I went, I deleted all the dual tank stuff, added a sump an did my own fuel system. It works great, an with 38gal of fuel I can still go well over 600mi between full-ups

What I would like about your single tank system is your not leaving 3-4 gals of fuel in each tank just to be safe and can effectively use more of the fuel on board before fill ups.

 

[davey99ps]

What I would like about your single tank system is your not leaving 3-4 gals of fuel in each tank just to be safe and can effectively use more of the fuel on board before fill ups.

Yea that's another bonus. I mainly did it to keep things simple with my fuel system. I figured the less complicated it is, the less likely it is to have something fail.

 

[SmokinBlack96]

Davey I have been looking for a post like yours all day.... Where did you end up putting the pump... Did you have to move it back since you were pulling from the rear tank

 

[backwoodsboy]

Davey I have been looking for a post like yours all day.... Where did you end up putting the pump... Did you have to move it back since you were pulling from the rear tank

I'm going to assume so.
Pumps like to push not pull, so the closer you can get to the source the better for pump longevity.

 

[SmokinBlack96]

I was just wondering where he mounted his cause my plans are to do the same things

 

[m j]

I am still collecting parts but I am going to use a bronco tank with Aeromotive in-tank pump.
pump and tank are all ready to go I just need to build the electric side and plumb the motor (was waiting to see if DI would sell me the rail fittings to feed the back of the head but that doesnt seem to be working out for me)

I am hoping the pump is big enough http://aeromotiveinc.com/products-page/fuel-pumps/11142-340-stealth-fuel-pump-offset-inlet-inline/
I bought a aeromotive 13129 regulator
got a wiring harness from a gas powered truck to see if I can rob the needed wires and connectors
original plan was to push fuel through the selector valve but I think the front tank will be in the way of my suspension plans so I am going to delete it and just plumb the baldwin filter base there using the factory style quick connects
I ordered a baldwin fuel filter to fit the base rather a poor random number choice as it is about 12" tall. anyone have a p# for a more normal sized filter to fit the fb1311 base

 

[bigbeanOBS]

curremtly switching to a single rear tank its just simpler ill post pics

 

[FrankTheTank]

Here is my filters. They are both the same size and much shorter then the wix filters. U really cant read the numbers but i can get them for ya when i get home.