I am also using a bottom feed system like HID. The only thing I did different was design a skid plate to protect that bottom fitting. The only downfall I have seen with my system is under hard acceleration, with an 1/8 of a tank of fuel it will run dry. If I keep it at a 1/4 or more I never have a problem. Under normal driving conditions I have never had a problem (even down below the 1/8 mark). However, I don't recommend that you run it that low even in stock form. There are picks in my gallery if anyone would like to see how I did mine.

HTH
Max

 

How about a bung in the (vehicles) left side (or front. frame provides protection on side) of the tank with a 1" tube sealed on the end. Make several holes in the top half of the tube. This would make your draw 1"~ from the bottom and provide a large amount of reservior for sloshing.

Randy

 

The way to do it is a hat shaped sump that will bolt around the hat brim and has a drain on one side and an outlet on the other. You don't cut the tank out to the sump, you just drill a few holes for the fuel to get in. this covers you when the fuel leaves momentarily and provides a drain to drain off water. I used to weld these to my big truck aluminum tanks. Works great and you can literally run the tank out of fuel.

 

I really like the bottom feed idea.

Where did you get the bungs? Local Ace have 'em? What ID should it be, 1/2"?

To avoid needing a skid plate, any reason I couldn't take it off the front or back of the tank as close to bottom as possible? What are you guys using for a pick up screen?

I wish there was a way to install the bung without pulling the tank.

 

After replacing a VP44 recently and running a TST comp. box, I installed a second complete low pressure fuel sys. I removed the in tank unit, added another draw tube, mounted a second stock transfer pump on the rail close to the tank. I ran a complete fuel line to the VP44 inlet banjo and used a double inlet banjo to tie both systems together there. I installed two, one way check valves, into each line. This allows both systems to work independantly, should one side drop pressure or fail altogether, the check valve will stop the other pump from feeding pack to the tank.
The part Im still working on is the needed pressure drop @ start up on the new system which is wired independanly. Im thinking of a Boost controller to run the second system, say, run at half voltage continously until it sees an increase in boost and raises the voltage to the pump so that when at full throttle and with my TST comp. box on a high level, both pumps are at full pressure, delivering twice the amount of fuel to the VP44, it wont starve and destruct its self again.
Anybody have any thoughts? Ive looked into the FASS and their $650.00 and a stock pump, how ever bad they are, is about $150.00

 

If you wait for the "wait to start" light to go out you don't have to worry about the start pressure.

the lowest part of the tank is at the pickup unit. Anything from 5/16 up is good for the bung.

 

No doubt I would have to be careful not to run the fuel level down too far.

 

I made a fitting that has four studs that go through a gasket and the tank then through a ring and secured by nuts. I'm not comfortable with the screw on type. My screen will be out side the tank after the valve and before the pump. I've wondered about the back of the tank also. Has anyone seen that done?

 

After thinking about it, the back of the tank is probably the best place. When you accelerate all the fuel will slosh to back of the tank, right where the outlet is.

A nylock in the tank wouldn't loosen. I just have to see if they make a nylock nut that will fit a bung that size. Luckily I've got one of the best Ace's around, they'll have something. I'm almost out of fuel too, so I guess I'll be doing this mod soon

 

Sounds like a bunch of over engineering and over kill. Take a bolt, maybe 3/4 fine thread, drill a hole through it the tap size for 1/4npt. Braze a washer under the head. Put it through the plastic tank which is one very big gasket. Another washer on the bottom and the nut, tighten it up, good and tight. It will never leak. screw an elbow into the bottom after tapping, hook your line up.

Why all the valves, screws, screens, and other junk?? Been working great for me for many miles. Works on millions of trucks all over the world. Why reinvent the wheel?

If you put it in the back, the bottom is curved, the darn thing will be a couple of inches higher than the bottom. In the center of the tank it works just fine. Use the KISS method, works great.

 

Thats a hot lookin set up! Nice job.
Eric

 

I'm quite familiar with the way you are speaking of and I have heard of them leaking and once its inside how do you retighten if it does? You can't without dropping the tank.
The valve is to shut off the fuel if you want to change the pump or clean out the pre screen which if inside the tank you cannot.
The prescreen is to keep the larger particles out of the pusher pump since there is no longer a pick up screen.
The the reason for studs and nuts is that it can be tightened from the bottom while the tank is in place and make what I feel is a more positive seal.

Over engineering? Maybe. Junk? I think not. Why reinvent the wheel? I don't know maybe because I can and I'm not comfortable with your type of setup, I want to do this once and make it easy to service when done and it will be unique, I like to build my own stuff.

 

MLR1's way is how I wish I had done it.

I found a really big heavy bulkhead fitting that required a 1" hole to be drilled in the tank.

I would have gone with the fitting he used:
http://www.performancecenter.com/pro...ber_RUS670850/

And get a low profile -6an 90 degree bend going right off that -6an male fitting there, and be done with it.

http://www.performancecenter.com/pro...ber_RUS614506/

You can see in my gallery, I have lost a bit of clearance as a result of using this big fitting. Makes me a little bit nervous at times...Especially being a 2WD truck, there is not a lot of clearance...

Otherwise it has been great. I actually cut off the bottom of the fuel module so I should've drilled directly under it anyway because I don't need to worry about clearance with it not there.

Anyone know how I could patch up the 1" hole in the tank so I can re-drill with the smaller fitting right below where the fuel tank module used to be?

 

Ok,you missed completely how mine is set up. The bung pictured is backwards for sealing on these plastic tanks. The washer brazed under the head, on the inside, and the nut outside, maybe 150 ft pounds of torque, won't leak. The flat washer will be about 2 inches diameter.

Do the same thing to plug the hole if you feel the need. Just use a bolt that fits the hole, braze the washer under the head, put it through the hole and tighten it down.

Don't use gaskets on it the tank is the gasket.

Ok, I'll go mind my business, sorry if I offended anyone.

 

Huh who me or the other guy? I did basically the same thing just used a bulkhead fitting which is what was available to me.


I just drilled the hole, plopped it in there with the thread hanging down and I was good to go--already set for 3/8" npt.

I was just saying I wished I had used the other parts that are a little more low profile so I don't have such a low hanging fuel line there.

no offense taken here