LS Swap - fitting from hard fuel line to braided line
 

Good Morning All,

I have been working on the fuel system for my 1973 LS3 swap and am trying to figure out the best way to connect the new 3/8" hard fuel line to the braided line. I have been looking at this thread:

https://www.corvetteforum.com/forums...part-list.html

And in particular the pictures below, to figure out what kind of fitting that is. The Russel fitting 644123 ( https://www.summitracing.com/parts/rus-644123/ ) is mentioned, but that looks different than the one in the photos. So I think the simple question is, can I use the same 3/8" EFI fitting that is used on the fuel rail to connect to the ends of my 3/8" hard line?

Thanks,

Scott

https://cimg2.ibsrv.net/gimg/www.cor...ac87072bf6.jpg


https://cimg5.ibsrv.net/gimg/www.cor...3d825de319.jpg


https://cimg8.ibsrv.net/gimg/www.cor...0bfc8890a0.jpg

Here you go-
The hard line is flared at 37º not the standard 45º used for brakelines.

http://www.russellperformance.com/mc...adapters.shtml


https://cimg9.ibsrv.net/gimg/www.cor...854edc2a70.jpg

Is all that plumbing to the top of the tank actually necessary? Is that where the fuel pickup is? You are going with a completely different motor, elex., etc. etc. You might just go with a simpler earlier tank. I know, $$$, but maybe in the long run better off. Admittedly I know nothing about what changes were made to the fuel system after 69.

These work nice
https://www.pegasusautoracing.com/pr...p?Product=3259

The fitting that connects to the fuel rail is a GM push connect fitting. There's a hydraulic tool that can that flare in hardline, but kind of expensive.
I used what Richard used on mine, but you have to be sure it's seamless tubing.
I've seen the braised on fittings and an external compression fitting used too on hardline.

All,

I think I have figured it out, the fitting is probably this one, which I will plan on using: https://www.summitracing.com/parts/ear-at165006erl

The project car came with all new brake/fuel lines from Corvette Central, so I will just remove the barbs at the end of the 3/8" fuel line and use these to transition to the -6 AN fittings.

Scott

I have used these on several EFI conversions with good success.

So let me get this straight - if you buy brake line and plan to use this as a fuel line, you always have to cut off the ends and re-flare it since fuel line should have a 37 degree versus a 45 degree flare that brake line does -
is that correct? I take it that -6AN connectors assume a 37 degree flare?

These do not need any flare to work:

Most steel brake line is non seamless. It's likely to leak if you do a single flare 37 degree fitting.

But assuming you have a tool to do a double flare 37 degree connection - you should do that instead of using on side of using an existing 45 degree brake line fitting that comes with the
brake line? This to connect to a -6AN fitting? It would be nice to have a chart of what fits up to what...

So it looks like I may have found the answer - double flare the tube if you want it to connect to a AN-6 fitting.

AN fittings and connections do not use double flares. Double flared tube is used with inverted flare automotive connections only. :thumbs:

Lars

I'm with lars. There's a reason 37 degree double flare tools are rare and expensive. If you're trying to use old non seamless line, the outside is corroded enough that it probably wont work well. Best solution would be a brazed fitting on a cleaned off old line. Or replace he line with seamless if you want the AN flare. Or buy the hydraulic flare too and make a GM push on connection if you use new seamless. Lots of options before I would go with old corroded fuel lines and a double flare.

I used nylon fuel line like the factory set up.It has been on for 3 years. No problems with leaking.

I may be in trouble and not aware of it-- I've been changing steel brake line to AN type fittings for years. Cut the line square, clean up any burrs on the inside and outside, throw the B-nut and sleeve on and a 37* flare. (Cheap Summit Racing flaring tool) burnish the flare and go!

Hoping it was stainless, they're usually seamless.

That is not my tank, just one I posted for the view of the fitting. I am putting a filter, pump and regulator on the passenger side frame rails.

The easiest and safest (especially for F.I. pressures) way to put an AN fitting onto a tube without the expense of the flaring tools is to use a Swedgelock fitting. I have several 6AN Swedgelock fittings left after my build. I'll send you one for $5.00 shipped. PM me.

73ls1 - How did you protect then nylon line from rubbing and/or interference issues with metal frame? Just secured down? I'm asking in case my Nickel-Copper line experiment goes awry.