when I started my swap (lq4 into 73 nova, nothing new here), I knew I wanted to try to make a custom tank setup so it would be as close to stock as possible and on the real cheep. although it has taken over two months of most of my free time I am almost ready to weld the sump on and be done with it. I have spent less then $400 on it and that includes a new tank.

the pump is a 255 walbro in-tank unit with install kit from summit (for a LT1)
I also got a longer 42" pig tail for the pump and a stock type flexy hose for the output. the tank is a stock replacement although I had the old tank and used parts from it. I wanted the pump to be as close to the back and low as possible so I made a custom sump out of bent sheet steel.


then I welded a small "tub" into the sump where the pump intake would sit so that it would have a reservoir and be slightly above whatever settled at the bottom of the tank because I designed it as the lowest point. (the sump has been treated with por-15 metal ready so it looks rusty)

then I placed the sender door from the old tank on the new one so that I could use it to mount the pump.(it will be brazed in last)

then I made the pump holder, it was tricky because it had to fit though the small door hole. the body of the holder and the pump bracket are made from a header primary. the body is held to the old sender door by two bolts welded through the door so the pump can be moved up or down. the pigtail goes through a small fuel line brazed in and sealed at both ends with JB weld.(nothing is connected because it is waiting for paint)

here are the holes in the bottom of the tank. I changed the orientation of the pump and that is why there is a rectangular slot that has been patched.

here is how the pump hangs down.

here is the old sender that goes in the stock location and will be used a the return line as well a the gauge sender.


I had to post up before I welded it because I need some reassurance that this thing at least might work. please give me input.

Question: I plan to use the stock fuel vapor line and run it to a charcoal canister and then to the engine, can I just hook a line from the canister to the evap line on the intake? I see the evap line has a plug on it, is it controlled by the ECM?

thanks

 

good thinking on your fuel tank setup. I'll be watching it..as I need some idea's for my setup.. I have something in mind that is simular. But still working on some new idea's.

I use the current port on the intake as a vacuum source to the Canister and it then runs to the tank vent ports. I just eliminated the EVAP valve/sol. I has worked so far and I don't have any flumes or problem with the tank building pressure or vacuum due to the fuel being used and lowering.

 

Pretty cleaver setup I do have to say. Much cleaner then running a sump like that and using an out of tank pump.

 

Just curious, what's up with that white "dishwasher" flex hose? Surely it's not fuel-rated?

 

Alot of late model senders use that kind of hose because the sender is spring loaded.

Looks good, I did kinda the same thing on my Nova, only I used a later sender that has a bigger opening, and the nwires already in it. I wasn't aware you could get a pump through the small factory opening. Should work good, mines never given me any problem.

 

thanks for the replies

bczee, did you use the stock evap bung on the manifold but with the electrical plug disconnected or did you just grab un-metered vacuum from wherever?

I have welded the tank on but I am having a hard time sealing all the leaks (I am inexperienced and using flux core, haste makes waste), how does one seal a crappy weld? piling more crappy weld has not done the trick.

thanks

 

Flux core is hard to use IMO. Too hard to get a clean weld with. But since you've already welded it on, you might try cleaning up the weld real good with a wire wheel on a grinder and then soldering or brazing it to fill all the pin holes left that are most likley causing your leaks.

 

I did the exact same thing you did (flux core trying to modify a gas tank) on a Honda Civic I converted to fuel injection. I had pinholes everywhere from blowing through with the welder. I used a wire wheel to clean everything up and then cleaned with acetone and then smeard JBWeld everywhere completely covering up all the joints. Haven't had one problem whatsoever since then.

I would have brazed it all up at the time but I was being too impatient to go to the store and get a new bottle to braze with so I decided to use JB weld instead. Honestly it has held up remarkably well. I pulled the tank off the other day after being on the car for years and it's still on there rock hard, no signs of cracking or chipping or delaminating or leaking whatsoever.

 

Yes I used that front EVAP bung/port, yes I discarded the EVAP Valve and solenoid.

On a LS1/6 Intake, there are two usable port (if you don't count the Brake vacuum Port). I fould that the rear one were the MAP and a port for the interior controls is direct Manifold vacuum (very High)... the EVAP port does act more like a Carb's Ported Vacuum port.. will drop off quicker than the rear port.

I tried both port for my Cowl Induction.. with the rear port being used, I found that my Vacuum operated Flapper would almost never open. Switching to the front EVAP port. The Cowl Induction Flapper operated almost normally.

Also, if once your worried about your tank leaking. Check into one of those Tank Sealer Kit. I used the Eastwood kit for my 48 Ford Truck tank and have not seen any leaks.

 

I have heard differing opinions on welding tanks since the metal is galvanized. Some say this can cause issues with the weld if you don't strip the layer off the tank, others say it doesn't make a difference. I've run into the same problems you're having but I'm using a mig setup...it probably is worse with flux. I used some gas tank repair sealer (two parts that you mixt together, putty like) that you can get at any auto parts store, though I used it on the top of the tank...don't know that I'd be comfortable using it on the bottom since there will be alot more stress there. Nice work so far though, keep us posted.

 

thanks for the advice, I have silver soldered over all the welds and leak tested it, I plan to then cover that up with jb weld more for appearances but also as a last line of defense (although in my research I have found stories about jb weld failing when faced with 10-90 ethanol-gas mixtures). I also have por-15 standard tank sealer for the inside, so hopefully there will be no leaks.

 

Since you have already welded over the galv. coating you have burned most of it away. The best way to finish it up would be to grind your weld back out and make your self a new landing to weld back over. Should do you up just fine

 

Here are some pics of the finished tank.





here is the filter i am using.


the tank goes in once I patch this hole.