I wanted to get away with out having to weld bungs on my tank, can I just drill/tap it? I wasn't sure if there are any ideas that are thick enough for that, in the stock "sump" area.

 

Save yourself the hassle and buy or build a sump on a new tank.

My first endeavour into this was me drilling two holes in my stock tank. One big hole in the bottom for supply and one in the top for the return.

I put a 10an bulkhead with a nylon washer in the supply. It sealed and worked. I put a 6an bulkhead in the top and it sealed and worked.

The only PROBLEM that I had was going around corner and slowing down. Since it had no sump to drain fuel into, it would sloch away from the pickup. The pump would unload and you could hear the pitch of the whine change. I know you do a lot of road driving so this probably isnt a really great option.

I ended up buying a tank that someone had welded a sump onto and havent had a problem since that day.

Good luck.

 

hehe. yea, the stock tank has a sump of sorts. but ill prolly play it safe and pick up one of those pre fabbed sumps from jegs.

hopfully I don't blow myself up

 

I've had the same experience. Two -10 bulkheads in the bottom of the stock tank and 2 -6s in the top. No leaks, but I have to keep over 1/4 tank of fuel at all times. I wish I'd spent the extra bucks to instal a sump the first time, but I'll deal with it until I'm forced to pull the tank again.

 

I dont know how you get all the gasoline fumes out but when i drilled my tank for the bulkheads, I put a water hose down inside of it while I drilled the holes. Not that you can do that and WELD at the same time. LOL It is a good way to purge the tank of fumes though. Unless you have money to waste on argon or something. LOL

Ive also heard exhaust fumes from cars works as a good inert gas to purge the tank. haha

 

ha really? just hook the damn tank up to the exhaust of my GFs car or something, lol. good idea tho I was thinking about filling up the tank cept for the last tiny bit where I was welding, but even after cleaning with soap/water that little area may be enough to cause at leastsome sorta bang. maybe test it with a open flame from a safe distasnce(lighter on the end of a LONG stick )

i figure a small area wouldn't be enough to send the tank across teh shop, but enough that I wouldn't wanna be near it.


I may try that exhaust idea.. with a similar test procedure

 

You can always get the tank boiled at a radiator shop. Dry ice will displace any leftover gasoline fumes.

Later,


Steve.

 

hm dry ice.

 

I recommend the sump option for obvious reasons, but if you plan on TIG welding the sump to the tank, get the competition engineering sump. The "jegs" sump is welded with brass; therefor you can't TIG it. ask me how I know.

For evacuating the fumes, I just let the tank set outside for a week or so, then I checked it with an "LEL" meter (thanks to my work) and it was fine. I cut out for the sump with a cutoff wheel on a grinder then TIG welded the sump to the tank, no problem. I didn't have to use any water or any other inert gas to evacuate the tank prior to welding.

good luck
...Brady

 

Do whatever it takes to make you feel safe about emptying the tank… (personally, fill to the top and flush it with water a couple of times, then flush it with degreaser/water, then I’ll let it sit out till it’s dry inside), then mark the location with for the sump, clean the area off well, then take a hole saw and cut a few large holes in the area. That leaves a baffle for the sump rather then cutting one large hole, and weld the sucker on.

I’ve used a mig to do it before, but a tig would be easier. With mig you tend to get pinholes where your welds stop and start or overlap (If anyone knows how to prevent this I’m all ears). I’ve never used a commercial ‘sump’ since I’ve heard horror stories about trying to get the jegs one to work, but there is a local metal fabricator that just bends up exactly what I want and I run a few beads around the seams.

 

I'm gonna try it without sumping. Putting the taps at the back part of the tank, where all the fuel goes when I accelerate. I'll post how it works, though you guys are making me doubt my decision. The tank is still out.

Rich Krause

 

That's exactly where mine are... Whether you bolt them in or weld them in, you're going to uncover the the bungs at low fuel levels when turning, and at very low fuel levels - when coming to a stop.

 

I would install 90* bulkheads at the top of the tank, and make pickup tubes out of aluminum fuel line. This setup is simple and effective. This closely resembles what you have right now from the factory, and is being used right now on a few high HP streetcars in my area without a single problem.
Just my .02

 

I ended up drilling a hole in the bottom of the tank, too. There is a nylon liner inside the tank which is kind of a stock sump, and it is not all that flat, so you have to be careful where to drill the hole. Installed a -10 90 degree steel aeroquip fitting with a nylon washer. I used the stock fuel supply line at the top of the tank as the fuel return. It has worked just fine. When the gas gauge shows 1/4 tank, it's time to filler up. The stock tank is very thin steel BTW. If you do weld a sump on, I wouldn't put any water in the tank at all, it may start the rusting process. The tank is not stainless steel. Do what Brady did, just leave it out to vent for a week or so.

 

Can I ask what you guys are tapping for??? Sorry if its an ignorant question...