Best way to add new gas tank connection

[matt63]

I pulled the gas tank to add a new 3/8 return line connection.  I figure the 1/4" vent connection is too restrictive.  I was going to have a new connector welded to the top rear of the tank.  Is there another way of adding a connection that doesn't require welding?  None of the Earl's type of fittings seem to be designed for this sort of thing. Thanks.

[Chryco Psycho]

O ringed bulkhead fittings would seal , you would need a tube adapter to attach a linee to the treaded fitting
or you could weld a fitting into the tank or sender

[matt63]

Thanks CP.  I saw some bulkhead fittings with teflon rings but you have to put them in from inside which would be tough unless you want it very near the sending unit hold.  I'll have a look at the sending unit and see if there is enough room there for a 6 or 8AN bulkhead fitting.  Barring that I could get something welded on to the sending unit which would save cleaning the tank which was done a couple of hundred miles ago.

[gkring]

Another down and dirty way is to put a nipple on the filler neck for the return line. Holley used to sell a "kit" to do this for their projection fuel injection conversions, but it was just a nipple and some hose. Have you tried the 1/4 vent line as a return yet? I have used a 3/8 return line on a few 800 HP plus fuel injected motors with no problem. If their is no pressure in the return line it should not cause any problems. When I had the four barrel projection on my 499 motor I used the 1/4 vent line in the sender as the retuen line with no problems.

[matt63]

I was using the 1/4" vent line but I think it is too restrictive.  The instructions on the regulator said the return pressure was supposed to be less than 3 psi or something like that, and if I recall correctly, it was higher.  I just wanted to get a 3/8" connection and then use the vent connection as a proper vent.  I just talked to the rad shop and they can braze a 3/8" npt flange on for $125 including cleaning so I'll probably do that now. Thanks.

[nivvy]

.  I'll have a look at the sending unit and see if there is enough room there for a 6 or 8AN bulkhead fitting. 

here is what I did....  im sure you can do it with aluminum line also  only pics I got right now.... 

[nivvy]

 

[matt63]

Thanks Stroker.  I had the rad shop solder on a 3/8" NPT flange to the upper back area of the tank this morning.  I'll get a pic but it's pretty straightforward.  The return line will just come in there.  I use the Goodrich fittings and the blue hose (Aeroquip I think) which is supposed to be legit with the tech guys if I ever get to the track.

[nivvy]

Thanks Stroker.  I had the rad shop solder on a 3/8" NPT flange to the upper back area of the tank this morning.  I'll get a pic but it's pretty straightforward.  The return line will just come in there.  I use the Goodrich fittings and the blue hose (Aeroquip I think) which is supposed to be legit with the tech guys if I ever get to the track.

rules state no longer than a 12" rubber fuel line from the sending unit to a aluminum fuel line....

Tech at the track is a joke in my area.... meaning they are real loose 

[matt63]

I'm told that the blue Aeroquip hose is legal unlike black rubber hose.

[Moparal]

Hmm. I would of drilled a hole in the tank and installed a 316 stainless 3/8 bulkhead fitting. I believe I just gave Go-Fish a few. 

[heminut]

I'm told that the blue Aeroquip hose is legal unlike black rubber hose.

The black rubber hose isn't illegal, NHRA just doesn't allow more than 12" in the system.

[matt63]

Hmm. I would of drilled a hole in the tank and installed a 316 stainless 3/8 bulkhead fitting. I believe I just gave Go-Fish a few. 

How do you put the fitting in as you need to install it from the inside? 

[Moparal]

Through the fuel sending unit hole

[matt63]

You must have long fingers!  I did think about putting it in reach of the sending unit hole but wanted it back/center in the end.