.
Dropped the tank and welded in a -6AN bung for my return line.
Everything went together real smooth,
better than expected.
Only thing that slowed me up was setting the valves off the roller rockers (what can I say, I'm not a chevy guy!)...
LOL...
A little tech write up on installing the -AN fitting install. Nothing major, but havn't done one in a while. A couple jokers at another site said MIG welding a bung into a regular fuel tank wasn't possible, I would just burn through like butter. Well......that made me want to weld one in even more!
So, I'm running a Bypass fuel regulator for a few reasons. 1) Cooler fuel. 2) Quicker response to changing conditions 3) choke out vapor lock issues 4) In general, a better regulated/stabile fuel system. The little 1/4" return port on the sending unit wasn't going to cut it. Most recommend the same size return line, if not larger. Being i'm running Stainless braided line and AN fittings all the way to the front and back, I went with a -6AN Bunn fitting for the return.
I bought a 18" chunk of 3/8" pre-flared line, cut to 9" and welded to the backside of the fitting. I used the flared side because it cups over the the inside of the AN fitting. Using the cut side I would loose some inner diameter, especially if the weld penetrated too far into the inside of the tube.
View attachment 113958
Next I bent the line. I did not want the fuel shooting straight back and turning the fuel tank into a Jacuzzi. I also didn't want it shooting straight down and boiling the fuel up like a cauldron....Hence the bend.
View attachment 113959
Drilled the hole and marked the straight up and down 12 o'clock position on the bunn. When going to weld it on I wanted the fuel to come out not only a 45* to the bottom of the tank, but also about a 45* to the side of the tank. Just to keep the agitation down. Those marks let me dial in the correct angle.
View attachment 113961
So.....can't be MIG welded eh? Hope one of the guys that was preaching that likes the picture below..I do! It was done with a Millermatic MIG welder and
.030 wire!
View attachment 113962
Being this fitting is obviously subject to leaking fuel, I wanted to make real sure it doesn't leak. One way to do that is backgrind the weld. Pretty common practice out there in the real world when it comes to any kind of Code welding for pressure vessels, critical systems or something holding nasty/explosive liquids. Backgrinding into the weld will open up any kind of porosity (gas holes), undercut, fusion issues or other issues not seen by the naked eye. Kind of an insurance policy. So, wrapped the threads (wouldn't want to turn a fairly easy job into a real PIA job with a slip of a die grinder) and ground the cap back down.
View attachment 113964
Everything looked pretty good so I welded up another pass, background/cleaned up the weld a bit and coated with some Zinc based weld thru primer (being I removeD the galvanized coating in the area for better arc). Coated with rust bullet after that.
View attachment 113966
All said and done, I hooked up my 6HP Shop-Vac and sucked anything I could out of the inside of the tank. Worked pretty well because the tank popped in about 25% (had to reverse it to pop it back out..lol). I also dumped in about a half a gallon of mineral spirits, sloshed it around and dumped. Tank is nice and clean inside, better than when I got it.
Kind of a pretty small task, but wanted to show it can be done, and easily for that matter. The benefits of running a return line are non arguable. It's simply a good system to run. So..Hope it helps someone out someday.
