AN-6 braided fuel line ends

[Jeff Berk]

I rearranged some items under the hood of my 260z and I need to replace several fuel hoses. I though I'd go with AN-6 instead of rubber hoses and worm clamps but I'm a bit confused on the connections. I'm assuming the threaded connections are all tapered BSP since the components are Japanese and nothing had O-rings. 

Because the vehicle traded hands a few times there is a strong possibility that some fittings (pressure regulator in particular) had NPT used where BSP should of been. If I use BSP now will that be a problem or will teflon tape fill the gap. It looks like there is a lot of pipe dope there now to seal the thread and it seems to have held up to the low pressure of the carbureted system.

What is the best way of dealing with the banjo bolts? I've seen a few AN-6  banjo bolt ends. Any suggestions on which ones will work on a Hitachi SU?

Thanks in advance for the help!

Jeff  

[Mike W]

I went AN throughout my fuel system all the way back to the pump at the tank, although that is not how I started off.  I knew little about these when I started the install but this site provided a ton of information on the fittings, how to assemble, etc.  So if you haven't  been here yet I recommend it highly.  They also sell all of the parts as well:

https://www.anplumbing.com/adapters/aluminum-adapters.html

I'm running triples and so my install is a little different.  However, when I originally started down this path, I did not want to go all the way to the tank and so I ended up cutting and flaring the OEM fuel hard line so that I could make the conversion from hard line to AN.  I found this hard line adapter on the site listed above.  They also make banjo fittings for AN but I believe you can also get a direct thread in to the carbs from an AN as well.  Check the site above.

One last thing.  I hope you have deep pockets.  Although I would do it again in an instant, it is not an inexpensive proposition.  Just a heads up.  Here's a few pictures of my install.  If you have any other questions, just let me know.

Mike.

 

[Jeff Berk]

I think I might go to Summit Racing tomorrow and take a diagram of the layout and my threaded fittings and see if they can provide a list of what I need. I’m not sure if they a selection of limey thread. 

[Stanley]

Fittings on the block, stock mechanical fuel pump and balance tube are all BSPT (except I don't know about water temp and oil pressure senders), but fittings on the carbs including banjo bolts are metric.

If there's a shop in your area that makes up hoses for big rigs and commercial HVAC systems and you know exactly what you need they can "hook you up", if you don't need to connect to existing hard lines on the car. They made me a 1000 psi tension-rated AN hose with AN/NPT adapters for an industrial FP gauge to the mechanical fuel pump, did it while I waited about 15 minutes, cost about $65. I also had to buy an NPT/BSPT adapter for the fuel pump.  Maybe better than buying tools and learning techniques unless you're doing the whole fuel system like Mike W.

AN fittings required for fuel lines in some racing classes and organizations - it's safer.

[wheee!]

 

Sorry to thread jack, but... beautiful job on the shaved valve cover!

[Jeff Berk]

What’s a “shaved” valve cover. 

[wheee!]

No spark plug wire bossing’s, no oil vapour return plug... welded and filled and painted. Very nice.

[zKars]

The banjo fittings on the early SU's are 12x 1.25, as they are on Mikuni side drafts. Webers use 12x1.50 just to be different. Earl's and the other AN suppliers have these banjo's as stock items. I've done lots of SU's with them. 

[Jeff Berk]

The line coming off the mechanical fuel pump is threaded as 1/8" and it leads to what I believe is the pressure regulator with a 3/8" inlet. The pressure regulator has a 3/8" outlet. 

I checked with ANPlumping.com and they no loner carry 3/8" BSP. Can anyone suggest a good source? I stopped by Summit Racing but they had nothing in BSP.

Thank you zKars for the info on the banjo fitting.

Jeff

Edited August 4, 2018 by Jeff Berk

[Patcon]

9 minutes ago, Jeff Berk said:

The line coming off the mechanical fuel pump is threaded as 1/8" and it leads to what I believe is the pressure regulator with a 3/8" inlet. The pressure regulator has a 3/8" outlet. 

I checked with ANPlumping.com and they no loner carry 3/8" BSP. Can anyone suggest a good source?

Thank you zKars for the info on the banjo fitting.

Jeff

Did you check on Earl's performance site?

Summit Racing or Jegs?

[Jeff Berk]

I just came from Summit Racing in Tallmadge, OH and they have nothing in BSP. Earl's performance site is slim pickings as well as Jegs. So far some China suppliers on e-bay and Pegasus racing are my best options so far.

[Stanley]

I'd be surprised if your FP regulator has BSPT fittings. Also, I tried using a 1/8" NPT fitting on the stock fuel pump - it wouldn't thread at all, BSPT works perfect. Maybe it's sort of OK to use NPT and goop instead of BSPT for plugs on the balance tube,  but I'd never use the wrong fittings for the fuel system.

 

McMaster-Carr should have the BSPT / NPT adapter fittings you need. The AN parts supplier or hose shop should  have AN/NPT adapters. As far as I know, there aren't any BSPT/AN adapters, so for the mechanical fuel pump you need BSPT to NPT, and NPT to AN. I used BSPT/NPT adapter, fuel pump to NPT Tee fitting with a hose barb and short hose going to the fuel rail, and the other end with NPT/AN adapter going to a AN hose for the fuel pressure gauge. It could also go to a FP regulator with a return line. For your setup I guess you have a dead-head FP regulator between the pump and the carbs. Those don't have as good a reputation as the type with return line so if you use that you might want to make sure it's top of the line from a manufacturer that racers use, not holley or spectre. Also, I'd want to be able to hook up a fuel pressure gauge temporarily or permanently between the regulator and the carbs to check on the regulator. Usually with a mechanical pump you don't need a regulator, but in any case it's a good idea to check the pressure.