Fittings to Convert 3/8" Hard Line to AN-6?

[Jim Doak]

Guys,

I'm looking into replacing my carb with a Holley Sniper EFI. Several of the questions I've got regard the plumbing of the EFI supply and return lines.

Due to limited space I'm considering running a large portion of the fuel lines using 3/8" steel or aluminum tubing. As such I've got a couple of questions for you folks who've plumbed similar systems:

1. What did you use for your 3/8" line? Steel or aluminum?
2. How did you convert your 3/8" hard line to AN fittings?

I ask because during my albeit brief investigation I've found that the hard line to AN fittings I've found are for aluminum tubing only with a pressure rating of 55 psi. The EFI system runs at higher pressure than that and I don't want any fuel leaks.

Please let me know if you've got any pointers.

Thanks.

[CDXXVII]

I used Swagelok fittings. They are for stainless lubing but work great. Here is an example for 3/8 tube.

https://m.ebay.com/itm/SSP-06-AN-Male-Flare-x-3-8-Tube-OD-Straight-37-JIC-316-Stainless-Steel/222775867390?hash=item33de79f7fe:g:4~gAAOSwNrBZ9Ws v

https://www.swagelok.com/en/catalog/Product/Detail?part=SS-600-6-6AN

[edwardb]

Basically the same connector is available from HAM-LET. Stainless Steel 316 Let-Lok Compression Fitting, Adapter, 3/8" Tube OD x 37 Degree Flare. Side-by-side they're nearly impossible to tell apart. Also are only for SS lines. Pressure rating is far in excess of your EFI system. They work great. I've used them on several builds. Breeze has them: http://www.breezeautomotive.com/details.php?prod_id=1073. I believe that Mike Forte also has them. I've actually found them on Amazon before as well. But don't see that size listed right now.

[RRussellTx]

I used Stainless lines as well.

Mark at Breeze Automotive can hook you up if you give him a call. I used his Fuel Pump adapter kit as a starting point and then bought additional Aeroquip fittings and hoses at various other sources to finish the stainless line connectors and the braided lines.

Couple of links to pics of my fuel lines. I stole many ideas from Edwardb's 20th anniversary build thread so thats worth checking out too.
http://thefactoryfiveforum.com/showthread.php?18974-20th-Anniversary-MK4-Build-Thread-10-of-20-8697&p=229782&viewfull=1#post229782
http://thefactoryfiveforum.com/showthread.php?18974-20th-Anniversary-MK4-Build-Thread-10-of-20-8697&p=239112&viewfull=1#post239112

Link to the Breeze Kit
http://www.breezeautomotive.com/details.php?prod_id=1101

Areoquip Catalog. (many of these are available on Amazon)
http://aeroquipperformance.com/files/2013-catalog.pdf

I recommend just calling Mark at Breeze though - I spent a fortune buying parts that were not exactly what I needed and he probably could have hooked me up in one order.







http://thefactoryfiveforum.com/showthread.php?18974-20th-Anniversary-MK4-Build-Thread-10-of-20-8697&p=229782&viewfull=1#post229782

[Jim Doak]

Thanks guys.

I did a little more digging, found edwardb's build thread and his fuel line write-up. Downloaded the Let-Lok catalog, etc. However, to simplify things it looks like it's time to give Mark Reynolds some more business. (I'm currently running an in-tank pump using Mark's fittings to convert the 3/8" and 5/16" fuel pump supply and return lines to AN-6 male fittings.)

These cars are a journey, aren't they?

[phileas_fogg]

I used standard 1/4" and 5/16" tube from Advance Auto Parts; it's inexpensive, easy to bend/straighten, and easy to flare. Lots of folks swear by the NiCop lines for their ease in bending, and lots of folks love the look of stainless steel. For a street car I'm not aware of a prevailing argument for one material over the other.

To couple the hard lines to the soft, I flared the end receiving the fitting to 37* (AN standard) and used Earl's tube sleeves (581905 = 5AN; 581904 = 4AN), tube nuts (581805 = 5AN; 581804 = 4AN), and reducer fittings (991907 = 5AN to 6AN; 991906 = 4AN to 6AN).

If you run 3/8" hard lines, you'll need tube sleeve #581906, tube nut #581806, and male to male junction #981506.

I've been unable to find a max pressure rating for the Earl's fittings (mine don't leak FWIW). The closest I found was for a shutoff valve, and that was rated to 300 psi. If you find a spec for these particular fittings, please pass it on.

Cheers,


John

[edwardb]

If you find a spec for these particular fittings, please pass it on.

The HAM-LET on-line catalog lists the Let-Lok 3/8-inch SS 316 connectors at 4568 psi. The fine print says 37 degree flare AN ends can have lower pressure ratings. But I think they're up to the task. :rolleyes:

[phileas_fogg]

Ha ha. But I was looking for a spec on the Earl's fittings...in aluminum... :D

Point is, that 55 psi number struck me as amazingly low, and I haven't stumbled across any information that suggested an aluminum AN fitting could/should not be used for EFI applications.

Cheers,


John

[Boydster]

Aluminum AN fittings are used in all kinds of aircraft for hydraulic and fuel systems, and they run a lot higher than 55psi... More like 3000.

[mikeinatlanta]

If a fitting is limited to 55 psi it isn't AN. There is no conversion from Steel line to AN, simply put an AN fitting on the steel line. If durability is a concern you can use either aluminum or steel AN fittings, however, steel AN is more normally used for things like brake lines, much higher pressures, or high vibration areas.

Regarding aluminum line. There are many grades of aluminum line and unless you know exactly what you are buying I'd advise not using it for fuel line. There is aluminum tubing that will easily hold the pressure, but stay away from cheap aluminum tubing for anything critical. Many states do not allow aluminum fuel line and will fail your inspection for it. I am using copper nickel pressure line and high grade aluminum for return.

[alv69]

I recently installed the sniper and I just bubble flared the lines and slid the hose the supplied over the flare, holley says this can be done in their instructions.

[mike forte]

Hi Guys,
I've been selling these for 20 years. really nice products in stock.
1/4" OD tubing to -4 AN
5/16" OD tubing to -6 AN
3/8" OD tubing to -6 AN