I just don't get it,

How do the sizes compare to standard plumbing sizes?

I know that the stock feed line is 9mm and i'm using a 3/8's compression to handle that fine and the return is 7mm if memory servs correctly and i'm using a 5/16th there.

It works, but i don't like the brass fittings on the car. Would rather have something a little more professional looking.


Also, has anyone been able to tap the stock fuel rails? Like with regular pipe threads?

 

an easy way to remember -an fittings is to put /16" on the end.

Example -8an = 8/16" or 1/2"

Example -4an = 4/16" or 1/4"

Example -10an = 10/16" or 5/8"




For the fuel rails, we welded -8an fittings on them. You might could tap them, but I haven't tried it.

 

AN Size - Equivalent metal tube OD

2AN - 1/8"
3AN - 3/16"
4AN - 1/4"
5AN - 5/16"

6AN - 3/8"
8AN - 1/2"
10AN - 5/8"
12AN - 3/4"

Comparison of NPT ID to closest AN size:

1/8" NPT - 4AN
1/4" NPT - 6AN
3/8" NPT - 8AN
1/2" NPT - 10AN
3/4"NPT - 12AN


Source: "How To Install & Use Nitrous Oxide", Joe Pettitt

I have -6AN fittings welded into the end of each fuel rail for fuel inlet. I have a 1/8" NPT fitting welded to the middle of the passenger rail for a fuel pressure gauge tap. I have a -6AN fitting welded to the diagonal crossover pipe for the return line.

 

Wow, thanks a ton guys

 

Thanks, that was helpful for me too.


Just WITF did they do that!?!?

 

This may help too:



http://www.speedwaymotors.com/produc...RSSEKK3MSC5MNE

 

I've got a drilled and tapped for AN on mine for the fuel press guage. I actually believe only one end was AN and the other was Metric... I'm not sure since i'm new to them also...lol

http://nkyfba.homeip.net/modules/Gal.../JamCam629.jpg

-Shannon