VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 1941 SD gas tank fitting

Turns out my gas tank, just recently refurbished has a ”˜male’ fitting...my new Inline Inc gas line came with a 1/2-20TPI...I found a connector that is 1/2-20 female on both sides...turns out the male on the tank is 3/8-27 (I think)...so...do I:
- find a connector that works?
- swap out the tank side? I worry about tinkering with something already set. Is there a pick up tube on the other side of the gas tank connector?

- I believe I have found a new connector that will work but fear taking that old one out not knowing the quality of threads etc.

Thoughts from the group?

I thought I'd update the group on this progress...I see 50+ people viewed the 'ask', but no responses...I told my wife it looks like no one wanted to touch this one! LOL.

So, in the last couple of days I've learned a ton about different connectors, "NPT", compression fittings, how to measure them, thread counts etc.

On the tank side I had a 5/16 compression fitting and my old fuel line had a compression nut and ferrule...same going into my fuel pump. My new Inline fuel line has a 1/2-20 NPT male fitting on both sides, and it obviously isn't going to work on that compression fitting (which I didn't know!) Finding a connector/adapter that would make a transition from compression to NPT was nigh impossible...they are out there, but not in the sizes that I needed...I found a female-to-female connector (NPT) but it still didn't fit on the compression fitting.

In general, I am super hesitant to take something apart, particularly around the gas tank if it isn't truly broken...usually results in more delay, something falling apart and just a cascading set of additional things to fix. Particularly when I wasn't sure what type of pick-up tube sits behind that tank connector.

However, I was able to find the right NPT fitting, 3/8 male x 1/2 female to accept the Inline fuel line fitting...an easy change on the fuel pump side, but not too excited to monkey with the gas tank side. This morning, after a good soaking in PB Blaster, the fuel tank fitting came right out, the 3/8 NPT threads on the tank look great and it appears it will accept the new fitting with no worries.

Long story short, I'm able to connect my new Inline fuel line into the gas tank and fuel pump without a kludged-together set of connectors to make it all work...it will be clean, neat and tight! Lessons learned: get totally educated on all the different types of connections out there, and be 'bold' to take apart something to make it work right! I think I'm set...on to the next project to get this car up and running!

I am not surprised no one jumped in as it can be very challenging to correctly identify the fittings with proper nomenclature. Most major units such as blocks-pumps-carbs etc are tapped for NPT (tapered pipe thread) pipe thread. Then it's adapted to a number of optional types that allow for installing a line . Add to that the varying interpretation of the names such as a fitting-connector-union-elbow- sae flare and inverted flare-compression and double compression . Glad to see you have found a solution and got educated at the sane time.

Yes, all good! I was most worried about taking that fitting off the tank...wasn’t sure if it was going to be so frozen on there and some weird pickup tube thing on the back side of it..but in the end it all worked out! This group has been so supportive with great info and points of view, so I was cracking up when no one jumped in...some times you go for it and this one worked out well. And yes, the amount and types of fittings out there is mind boggling, but this will be a clean fix!

All the best

Chris

"just recently refurbished" backed me off from making suggestions. Obviously they added a fitting during the refurbishment and maybe they changed how the pick-up tube was mounted , etc. Hard to trouble shoot stuff like that from a distance.