TEA 20, fuel line threads

[Bill Brox]

Hello,

I have come across my most peculiar task so far in life it seems. And that is to determine the thread standard for the fuel bowl and carb. on a TEA 20 from 1948.
The fuel bowl is AC, the common one with a glassbowl, and the carb is the well known Zenith 24 T2 carb.

The thread in the fuel bowl for the pipe is about 7/16" and has 24 tpi.
What kind of thread standard is this ? I have found something called ADM threads, but I can not find any information about it, other that it is 7/16" and has 24 tpi. I have tried to goodle it. No luck.

Then it is the carb. The nipple has a diameter of 11.8 mm, which is about 15/32", and my 20 tpi gauge does not fit perfect, so I guess maybe it is 19 tpi or 21 tpi. It is not 18. Unfortunately I do not have a better gauge, so it is 16, 18, 20, 24, 27... you get the picture.

Can anyone enlighten me in this most peculiar matter ?


Bill

 

[Don Norris]

I use brake line for my fuel. That said, here's a link to a site and some info about sizes and types of flares.

http://store.fedhillusa.com/technicalhelphowtopdfs.aspx

Hope this helps you.
Untitled URL Link

 

[Don Norris]

and here's a link for NPT, National Pipe Thread, sizes, which is in the bottom of the fuel tank.

http://www.plumbingsupply.com/pipethreadsizing.html
Untitled URL Link

 

[Duner Wi]

For the fuel bowl look at a 1/4 inch brake line for some applications on old American cars.
I measured a flare nut and it came in at .436 thouands and 24 TPI.My TO20 Fergy has 1/4 inch steel fuel line so I think a brake line will work for you at least on one end.