fuel cell plumbing

[alwaysFlOoReD]

I'm installing an 8 gal. fuel cell in a '91 Ranger race truck with stock motor and am trying to utilize the existing components as much as possible. I haven't checked my manual yet it's at the garage [25 min away]. Do I need an in tank pump or [IIRC] can I use one on the rail without a low pressure pump. I'm guessing not but would like confirmation. The fuel is accessed from the top of the tank like these;
http://www.rciracing.com/
Thanks,
Richard

 

[gwaii]

i've used the rail pump without the in tank before and it worked just fine,except that it won't self prime if you run out of gas.

 

[alwaysFlOoReD]

So how do I get the initial prime?
Richard

 

[scotts90ranger]

a '91 only has the high pressure in tank pump

 

[alwaysFlOoReD]

a '91 only has the high pressure in tank pump

Yeah, thanks, I found that out today.

What I have on hand is a frame rail pump from an '88 f-150 and one other frame rail pump from an unknown Ford. I think these are high pressure pumps. I have 5 days to get my truck ready for the races on the 3rd and 4th. Unless someone can verify that these will work for suction without a low pressure pump then I'll find a low pressure and plumb it in.
Thanks everyone,
Richard

 

[crusin93]

What you need to do is plumb in a high pressure pump along the frame rail as close to the cell as possible. It should be mounted level or a little below the bottom most part of the cell. High pressure pumps push a lot better than they pull. You need it to flow at least 85lph at 40 psi. All hipo aftermarket inline pumps far out flow that minimum. Without additional info (delivery system, sanctioning body rules) it's hard to recomend anything but basics.

 

[alwaysFlOoReD]

crusin93
Basics is what I need
I'll try to give more info.
Class rules are stock fuel delivery system; efi has to stay efi, no aftermarket parts. I have a stock '91 Ranger 4.0l with stock fuel delivery system. The rules state a fuel cell with a bladder inside which I have. The stock system has the fuel pump inside the tank which I can't do in the fuel cell as far as I know. As previously stated I do have a frame rail pump from a '88 f-150 as well as one other that I could use IF it will work. As far as I understand the system, there is a low pressure pump in the stock tank that feeds the high pressure pump. The '88 was feeding a 5.8l so I don't foresee any delivery problems on the pressure side, just wondering about the suction side. Gwaii mentioned he had done this but hasn't said how he got it primed in the first place. In the link previously you can see the fuel cell 'fuel pickup' is at the top of the cell so the pump has to work to get the fuel up and over before any thing happens.That what's worrying me.
Thanks,
Richard

 

[crusin93]

I can't guarantee that the high pressure 150 pump will work. It is similar in design to the aftermarket units. Try this. Rig up a jig on your bench using a non flamable liquid in the cell and some fuel tubeing with just hose clamps. Use as little hose as possible between the cell and the pump. Run 12V to the pump and see if it will self prime. It it will work on the bench it will work in the truck.

 

[alwaysFlOoReD]

Good idea, I'll try that tomorrow.
Richard

 

[crusin93]

Okay. Good luck. I have to stress the importance of having the pump mounted level and below the bottom of the cell. An 1/8 inch below, or a foot it does not matter. As long as a siphon effect can be achieved the system will work. I'm just not sure a 22 year old pump is capable of creating adquate suction for initial (dry) prime. Let us know what you find.

 

[gwaii]

sorry about the lack of reply on this-been busy.to prime just siphon feed into the feed line from a seperate container(jerry can mounted higher than the pump)and run the pump for a few seconds to fill the lines.you should hear when air stops coming through the return line.then reconnect the supply line to your cell.as long as you don't run out of fuel you should be ok....one other thing-mount the pump lower than the bottom of the tank so it siphon feeds from the tank.that is why the ford installations of these pumps is always low on the frame rail-even with the primer pump,there is always a gravity feed to the pump as well.

 

[alwaysFlOoReD]

Well, it seems this discussion is moot. The fuel cell mount I built is lower than the frame rails. I did this a while ago thinking that a lower center of gravity is better for cornering. So I bought a C$100.00 [ouch] generic low pressure pump to feed the stock high pressure pump. I'll be plumbing it in tomorrow.
Thanks again for all the help,
Richard

 

[gwaii]

doh!......oh,well.what's another $100 in a race truck build.those things eat up money as bad as boats.