instead of sumping the tank, just putting in a fuel cell bulkhead in the bottom/rear portion of the tank. i'm a little leary about welding a sump into my tank. here's a bulkhead like i'm thinking of:


link to summit store:
http://store.summitracing.com/partde...5&autoview=sku

obviously a sump would be the better solution, but this would take minimum fabrication and i've seen it used before.

 

i bought the sump from the jegs brand and paid a local radiator shop $65 to weld it in, they cleaned the tank, AND painted it a shiny black color within 2 days of dropping it off. Only recommendation which I wish I would have done would be to have a -10 or two of them put on instead of these dinky -8 holes

 

not too many fab shops around here, but i can think of one right now, i'll call them. rich, if you read this, let me know if you're willing to weld on my gas tank that's already had fuel in it at some point!

 

-8 is always too small. I use a plastic fuel cell in my car and it has two -8 feed fittings. One is capped off. I took the other out and installed a -10 fitting. The additional -8 is good for a second feed like to a NOS system.

Trouble with installing something like that on the back of a regular fuel tank is that without a sump, you can run out of fuel when there's still a gallon or 2 still in the tank. It could be installed directly on the bottom at the back but then when fuel gets low it can move away from the fitting. With a sump, the fuel is forced to stay at the bottom where the fitting is.

Welding a gas tank isn't hard. Remove it and take it to a car wash. Steam clean the inside for 30-60 minutes. I'd recommend a rad shop though because they can also pressure test it to ensure there's no leaks.

 

I had a shop tig weld in a bung with pipe threds at the bottom of the tank about 12 years ago and have fittings I screwed in to convert it to an size I have a #8 line and have gone 9.70 on spray I can also tell you I had to run the car on the nitrous line that goes to the front it is 3/8 car ran 10.60s with no proublem.

 

i welded in 1/2" pipe bushings in my factory tank.I have a 1/2" pipe to a #10 90* fitting to a stainless steal filter to a aerospace ultra 350 pump in the rear of the car.

i got hte pipe bushings from home depot in the plumbing section and ground off all the galvanizing

 

How do you propose tightening this bulhead fitting up??? It takes a wrench inside to hld the one side while you tighten the other. I bought a jegster sump and had a shop weld it non, then i bought that -8 bulkhead fitting and insalled it on the top of the tank for the return...luckily my buddy had small hands and was able toreach into the tank and hold a wrench whil i tighten it from the outside.

If i coud do it all over again, I would've bought a brand spankin new tank (priced one from Oriley's prior to taking exiting tank to shop, and it was only $125 at that time...brand new no fumes, couldve welded the sump on and pressure tested in the garage...but i had a place do it and lost a pump thanks to a piece of welding wire that broke off and floated around...even after he "washed" it 3 times when he was done...too many baffles internally to ever think you'll get it all out.

so get a sump, do it rght, an depending on price of tank you wont have diddly invested since it's be a great DIY project. FWIW, when i did the -8 bulkhead on top of the tank, I ran a pig tail of -8 line down with a femal AN fitting...came in usful when i fought this thing originally since i was gong back and forth between a dead head pump and return style pump..just a way to give yourself an option while your at it..but i do agree with Stephen, just putting a pluginthe bottom of the tank is ati productive since your setting yourself up for "that one time" and thiings dont work just right.

 

I have a good soloution, i can sell you a tank with bungs in it for a good price, I took it out when i made the tank in the car....I can get a pic of it if you want matt, I think it is a -10 bung, and it also has a drain, thiis was the tank that was in the car, just dont run it real low at the track.

 

not meaning to hijack but i have this http://store.summitracing.com/partde...5&autoview=sku fuel cell with -8 fittings in the top. do i need to have them replaced with -10 or where you guys just ribbing each other?

 

does your pump require -10 or larger?

if not then no

if yes...then u have your answer already.

 

Just about all fuel cells supply at least one -8 supply fitting. Under normal usage, this is usually enough. High flow pumps however should use a -10. Feed as much fuel as possible to the pump to prevent cavitation. From the pump to the regulator, a -6 can be used.

 

rich, shoot me a pm on pics and price

 

will do, forgot camera today though lol. upon further review, it looks like a - 8 fitting. I will verify size though.

 

ok got pics

 

so did you figure out if it was -10 or -8?

 

-8 x 2 one was a drain i guess, but you can run your nitrous out of the other bung later lol

 

haha, alright, shoot me a price

 

What do you think would be better? A bulkhead fitting on the bottom of the tank with no sump, or the factory pickup setup?

I'd assume they would both have the same probability of fuel splashing away from them? I'm about to upgrade my fuel system but have no room for a sump. My tank has a ton of baffles inside it, I would assume that the sumpless bulkhead on the back/bottom of the tank would still be better than routing a 1/2" line through the sending unit?

 

how is yourset-up any different than any of ours that d run a sump on our factory junk???

just one of these perfect examples of doing it right-now, or doing it right later...get the cheap sump, pay a shop the $50 to have it installed and just call it done. Install the bullhead fitig on top of tank with a pig tail line coming down and cap it off if you want, but that way you have a return line should ou step up and install a return style reg...

wy old pics, but you get the idea:

 

I have factory style exhaust so the muffler is sitting right under the tank.... I never had a problem with the factory setup whatsoever and I also never run the car low on gas. From what I remember the section where the factory pickup is located is pretty well baffled, I couldn't see there being a fuel splash problem unless you were ridiculously low on fuel - I drive to the track, I need enough fuel to at least make it to the nearest gas station afterwards so I never go too low.

I understand how the sump is the best way to go but I also don't see how doing it the other way is really all that bad of an idea...

 

yup.....i bought a new tank, and welded the sump in......i washed it out about 20 times......dried it, blew it out, vacuumed it out, and magnet'ed it out for hours haha, i STILL don't think i got it out, thats why the pre-filter is huge.

linky link.... https://www.thirdgen.org/forums/powe...3-project.html

 

This is the very thing that Lou was doing to the Mustang Roadracer on Musclecar. No sump, just 2 bulkhead fittings on the bottom of the "roadrace g-machine stang". Looked sorta IFFY at best to me.


Kevin

 

well, i'm gonna "give it a wirl" as it were. i gotta have something more than i have and this seems like a good idea in my head. i don't run the car low on fuel, i race with a full tank...like IHI said, it's one less thing to worry about between rounds. if it proves to be a problem, i'll have my existing tank sumpped and call it a day.

 

thats cool man......if you end up going the sump route though, just buy a new tank.....its easier, simpler, and probably end up being cheaper. as you don't have to haul the tank someplace.....have it cleaned etc.

you just buy the new one, and install.......no worries. and its nice and clean....alot easier to weld too

 

AMEN!!!! and alot less expensive than new fuel pumps and lost rounds-no brainer after being there doing that.

 

I do agree that a sump is best but one question remains... the stock pickup is roughly 3/4" off of the bottom of my tank, what is the difference between the stock pickup being off the bottom that much and the 10an bulkhead fitting plumbed through the bottom in about the same place? What keeps the fuel around the stock pickup that wouldn't keep the fuel around the bulkhead fitting?

Also, why would the return line have to be plumbed in through the top of the tank? The stock return line exits just beside the intank pump. Why couldn't the return line fitting be beside the feed fitting? Just a few questions that popped into my head.....

Kevin

 

fluid pressure.....if you return fuel UP into the tank, the pump is working alot harder to push the fuel back in against the weight of all the fuel in the tank pressing down on it.....doing it from the top, back into the tank and to the bottom makes that a little less dramatic, and by not returning it at the top cuts down on aeration of the fuel.

 

Is there anything wrong with a sumped tank that leads to an external pump, but also leave the intank pump functional, so you have two fuel pumps that Y into one line?

 

I wasn't thinking of the weight of the column of fuel on the return side... I thought of it helping to feed the pump.

So, any thoughts on the bulkhead fitting vs the stock pickup having any less/more fuel starvation issues?


Kevin

 

I think it would be about the same, however, I like the idea of just a new tank with welded on baffle, much cleaner and nicer. You are dropping the tank anyways to weld/bolt on a fitting, might as well do it with the baffle.

 

If the return line goes all the way to the bottom of the tank you'll have the same head pressure as if you returned it through the bottom.

 

Good point, I misread the part about "reducing aeration".... So, in theory, putting the feed and return bulkhead fittings in the bottom wouldnt be much different than the stock feed and return lines in terms of return head pressure and fuel starvation in cornering/braking. As long as the bulkhead fittings were close to the same point as the stock pickup, everything should be fine?

Kevin

 

Head pressure isn't all that significant anyway, at a height of 1 foot it's only about 1/3 PSI for gasoline.

 

no you don't.......add the length of the tubing underneath the tank leading up to the fitting......

if its on top, subtract the distance from the top of the tank, to the top of the fuel.....because that distance reduces net head pressure.

the bottom of the tank is your zero point, now anything above that is negative (in relation to head pressure) and anything below it is positive.

when you're talking about a column of liquid, that can make a significant difference

you're also not considering what happens to the fuel during a launch, if you're returning to the bottom of the tank, from underneath.....that pressure is fighting the fuel, and it is very significant, if its on top coming down the fuel in the tank is being pulled away from it, and thus its being pulled in.

 

well, i'm gonna run the return line through the current feed line, which is a -6 line coming out the top of the tank. would it be better to shorten the current pickup though when i turn it into the return line? like right now it's about 3/4" off the bottom of the tank, i could shorten it to were it's just coming in right on top of the tank...does that make sense?

 

it'll splash the fuel into the tank constantly and aerate the it if you do that, unless its totally full all the time....you're best bet is to leave it or if you want to shorten it, don't take much off it so that it stays covered with fuel.

 

Like i said before, i just have a -8 bulkhead mounted in the top of the tank for my return line hook up, it's been this way for 4yrs, street driving/racing i've never had any isses. I dont believe areating is an issue on the top since by the time it goes through a spinning pump it get areated again, but it puts it through at such/volume pressure it must sort itself out....i think guys are way over analysing this to be honest...not flaming anybody, but the same menatlity of my kitchen light quit working, lets call the power compnay before we check the light bulb...seriously intelligent people suffer from this all the time, i get to see it almost daily..so like i said, not a flame, just a trait that comes with being overly smart LOL!!

Doing a return next to the fitting on the bottom of the tank does more harm by creating a current of flow..much like a river current, it gets going one direction and it will make the "gravity fed" fuel going into the pump work that much harder to get in the line since it's fighting the fuel flow current from the return line.

 

sounds like a plan, though it's interesting to me that the factory setup is just a little nub sticking into the tank from the top.
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hehe, tell me about it. this is why i haven't decided on a new motor yet...i've analyzed every possible combination from every different angle and can't come up with anything good yet. guess that's why i'm going to school to be a mechanical engineer, lol!

 

hmm, lets see, how about a 400 plus inch sbc, with a pair of turbos on it, that would change your fuel line needs though......