Can fuel line be flared?
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
Can fuel line be flared?
I'm tired of dealing with these connectors and just want to put in a -6an fitting in it's place.
Just wondering if the hard lines can deal with being flared or worse find out they are plastic....
Just wondering if the hard lines can deal with being flared or worse find out they are plastic....
Race Director
Joined: Jan 2006
Posts: 10,554
Likes: 33
From: Not on either liberal coast.
I'd be very concerned about forming a perfect flare to withstand the higher fuel pressure of today's cars. There must be a reason that none of the manufacturers use flared fittings anymore.
In the "ol' days" when fuel pressure was 4-8#, flared fittings were common...
In the "ol' days" when fuel pressure was 4-8#, flared fittings were common...
Pro
Joined: Dec 2003
Posts: 654
Likes: 1
From: chandler az
You can also buy an adapter fitting and go from the quick disconnect to AN connector and disconnect at the AN connector.
I'm not thrilled with the disconnects, but with a cheapie autozone disconnect tool it's not that bad. It reminded me of some German made disconnects that held a big one inch water line. They were kind of the same style but about three inches in diameter. Now those were a pain in the *** to take off and remove.
I'm not thrilled with the disconnects, but with a cheapie autozone disconnect tool it's not that bad. It reminded me of some German made disconnects that held a big one inch water line. They were kind of the same style but about three inches in diameter. Now those were a pain in the *** to take off and remove.
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
You can also buy an adapter fitting and go from the quick disconnect to AN connector and disconnect at the AN connector.
I'm not thrilled with the disconnects, but with a cheapie autozone disconnect tool it's not that bad. It reminded me of some German made disconnects that held a big one inch water line. They were kind of the same style but about three inches in diameter. Now those were a pain in the *** to take off and remove.
I'm not thrilled with the disconnects, but with a cheapie autozone disconnect tool it's not that bad. It reminded me of some German made disconnects that held a big one inch water line. They were kind of the same style but about three inches in diameter. Now those were a pain in the *** to take off and remove.
Tech Contributor
Joined: Jan 2007
Posts: 19,397
Likes: 1,137
From: Dyer, IN
I'm confused at what you hope to accomplish. Unless you install a complete custom fuel system, you are going to have a quick disconnect somewhere...either at the fuel rail, or at the fire wall. Perhaps I'm missing something, but it doesn't make much sense....based on my understanding.
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
I'm confused at what you hope to accomplish. Unless you install a complete custom fuel system, you are going to have a quick disconnect somewhere...either at the fuel rail, or at the fire wall. Perhaps I'm missing something, but it doesn't make much sense....based on my understanding.
I've tried most variations of fuel systems out there and currently run an aftermarket in-tank and external in-line pump to help pressure when extra volume is required. I have hard lines running thru the drivers-side rocker panel, feed is -8 y'd to -6's into Aeromotive rails. Rails. Returns are y'd back to a referenced regulator and flow -6 back to the tank. Aside from simplifying things because the new setup isn't going to do ridiculous power, I am moving hard-lines from the rockers back to the tunnel. Since I've run flared fittings beyond 80 psi w/ no problems before, I see no reason to go with a disconnect when it makes sense for me to do otherwise.
I do agree that the stock system, for most, is good enough left alone
Last edited by AVB; Apr 14, 2010 at 02:07 AM.
Melting Slicks
Joined: Apr 2003
Posts: 2,285
Likes: 16
From: Nashville TN
the lines are aluminum and can be flared. I developed a pin hole leak in a line once. Cut the hole out. flared each end and slipped a piece of rubber hose over the line. This was just to get me by until I could fix it properly.
You can buy a fitting that converts the quick disconnect to a -AN fitting. You might check into that. IMO, I think the GM quick disconnect fitting provides a better seal than a AN fitting and braided line.
You can buy a fitting that converts the quick disconnect to a -AN fitting. You might check into that. IMO, I think the GM quick disconnect fitting provides a better seal than a AN fitting and braided line.
Tech Contributor
Joined: Jan 2007
Posts: 19,397
Likes: 1,137
From: Dyer, IN
My question specifically is whether the existing fuel feed line, right above the drivers side manifold, has been flared (double-flared in my case) by anyone or can be confirmed that it really is some sort of metal and can be flare-able. I can and will use quick disconnects elsewhere but right where the feed ends (right above that exhaust manifold) is where I want to put a -6 tube and sleeve and flare it.
I've tried most variations of fuel systems out there and currently run an aftermarket in-tank and external in-line pump to help pressure when extra volume is required. I have hard lines running thru the drivers-side rocker panel, feed is -8 y'd to -6's into Aeromotive rails. Rails. Returns are y'd back to a referenced regulator and flow -6 back to the tank. Aside from simplifying things because the new setup isn't going to do ridiculous power, I am moving hard-lines from the rockers back to the tunnel. Since I've run flared fittings beyond 80 psi w/ no problems before, I see no reason to go with a disconnect when it makes sense for me to do otherwise.
I do agree that the stock system, for most, is good enough left alone
I've tried most variations of fuel systems out there and currently run an aftermarket in-tank and external in-line pump to help pressure when extra volume is required. I have hard lines running thru the drivers-side rocker panel, feed is -8 y'd to -6's into Aeromotive rails. Rails. Returns are y'd back to a referenced regulator and flow -6 back to the tank. Aside from simplifying things because the new setup isn't going to do ridiculous power, I am moving hard-lines from the rockers back to the tunnel. Since I've run flared fittings beyond 80 psi w/ no problems before, I see no reason to go with a disconnect when it makes sense for me to do otherwise.
I do agree that the stock system, for most, is good enough left alone
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Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
I'd be very concerned about forming a perfect flare to withstand the higher fuel pressure of today's cars. There must be a reason that none of the manufacturers use flared fittings anymore.
In the "ol' days" when fuel pressure was 4-8#, flared fittings were common...
In the "ol' days" when fuel pressure was 4-8#, flared fittings were common...
What do you think are on your brake lines?
GM went with QD for 2 reason's "COST" it's cheaper to make and it's quicker to assemble!
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
a flare fitting is going to be much more reliable the a QD. only problem is that once the flare joint is disassembled, the flare should not be reused. i remember a fuel seal tester my class designed in college that used a very thin aircraft fuel at around 350psi i beleive it was. nearly all the connections we used were flare fittings.
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
the lines are aluminum and can be flared. I developed a pin hole leak in a line once. Cut the hole out. flared each end and slipped a piece of rubber hose over the line. This was just to get me by until I could fix it properly.
You can buy a fitting that converts the quick disconnect to a -AN fitting. You might check into that. IMO, I think the GM quick disconnect fitting provides a better seal than a AN fitting and braided line.
You can buy a fitting that converts the quick disconnect to a -AN fitting. You might check into that. IMO, I think the GM quick disconnect fitting provides a better seal than a AN fitting and braided line.
I believe you on the GM connector being a better seal... at least when in tight quarters and when being put together in an assembly line.
It is definitely more convenient and may end up being used (kept) if I can re-position/bend the line to get it further away from the exhaust heat, Btw, it'll be used as a return line so it'll be seeing very little pressure and a new steel line is being put in for the feed.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
As long as the line is a size that can accept a flared fitting you should be fine flaring it. I don't even see why you need a double flare. I'm not sure the aluminium lines will take kindly to being double flared and besides it's is only around 60psi or so. Single flare it and crank the fitting on tight and you'll be fine.
Peter
Peter
Race Director
Joined: Oct 2002
Posts: 16,477
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
The double flare is no better at sealing or rated for higher pressure than a single flare. Stainless tubing, for example does not need a double flare.
As for flaring, and pressure, I quite often flare steel tubing for use in hydraulic systems that sees in excess of 3000psi. The 60psi fuel system is not even close to the ballpark of "high pressure".
One last thing for the OP, please note most double flare tools are for a 45° SAE flare angle.
The (higher pressure rated) AN/JIC fittings are 37° taper. You MUST flare it @ 37°, or it WILL leak!
Last edited by Y2Kvert4me; Apr 14, 2010 at 06:13 PM.
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
Thank god the stock lines are aluminum...I hear ya though on getting the right taper
