Zmanco Posted April 28, 2007 Share Posted April 28, 2007 As I get ready for my FI conversion, I'm considering putting in a hard fuel line return on my 73 but am finding that there is nothing available at my local autoshops. The closest is to use some 5/16" brake lines in 60" lengths and join them with unions, and then cobble together some fittings to end with a 5/16" nipple. But this seems a bit more kludgey than I'd like for fuel. I started out thinking I was going to use the vent line on the drivers side for my return, but it means pulling a long length of rubber hose (I'm using the stock fuel rail) to get to it. For a foot or two I don't mind running rubber hose, but for more than that I'd rather run hard line. How have others done this? Quote Link to comment Share on other sites More sharing options...
John Scott Posted April 28, 2007 Share Posted April 28, 2007 As I get ready for my FI conversion, I'm considering putting in a hard fuel line return on my 73 but am finding that there is nothing available at my local autoshops. The closest is to use some 5/16" brake lines in 60" lengths and join them with unions, and then cobble together some fittings to end with a 5/16" nipple. But this seems a bit more kludgey than I'd like for fuel. Daniel, I started out thinking I was going to use the vent line on the drivers side for my return, but it means pulling a long length of rubber hose (I'm using the stock fuel rail) to get to it. For a foot or two I don't mind running rubber hose, but for more than that I'd rather run hard line. How have others done this? I went to US performance in Loveland and bought a roll of -8 aluminum...actually two rolls. Any well equipped speed shop should carry -3,-4,-6,-8,-10. Bought a tubing cutter and bender as well. Check your Jegs or Summit catalog. I found some compression fittings from home depot rather than high dollar Russell, Earls etc. Not as pretty with colored anodized, but do the job. Always passed inspections at track. Hard lines are a PITA, but worth the effort. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted April 29, 2007 Author Share Posted April 29, 2007 John, from the pictures it looks like you're using braided fuel line. For my application that's a bit more than I need, hence I was trying to go with hard lines. Do you think there's any problem with using brake line? I figure the brakes generate much more pressure than the FI fuel pump, and I can't imagine there being any problems with gasoline and the metal in the brake lines. But wondering if I have overlooked anything? Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted April 29, 2007 Share Posted April 29, 2007 All of the on line parts retailers sell coils of 1/2 inch aluminum hard line. Something like $25 for a a 25 foot coil. More than enough to do a Z. I bought the 90-10 copper nickle stuff from a place in England. It can be used as either fuel line or brake lines. So yeah, brake line can be used as fuel line. Just get the right diameter Quote Link to comment Share on other sites More sharing options...
John Scott Posted April 29, 2007 Share Posted April 29, 2007 John, from the pictures it looks like you're using braided fuel line. For my application that's a bit more than I need, hence I was trying to go with hard lines. Do you think there's any problem with using brake line? I figure the brakes generate much more pressure than the FI fuel pump, and I can't imagine there being any problems with gasoline and the metal in the brake lines. But wondering if I have overlooked anything? The only braided line I use is from the regulator to the carb inlets. Makes changing jets easy since they flex. From tank to filter, fuel pump, to regulator and back to fuel tank are all -8 alum. I can't say what using a steel line would be like, but might be more likely to corrode to water contamination in the fuel. Aluminum is really easy to work with and compression fittings do not need flaring. Quote Link to comment Share on other sites More sharing options...
TimZ Posted April 29, 2007 Share Posted April 29, 2007 I ran a pair of -6 lines for the supply and used the stock return line, and this has worked very well for me for several years. -6 is MUCH easier to work with than the larger sizes. Quote Link to comment Share on other sites More sharing options...
Cethern Posted May 5, 2007 Share Posted May 5, 2007 Daniel Stop by Ontrack Performance here in Denver they are off Santa Fe and Dartmouth. I think their address will show South Platte & Dartmouth. All so there is Peterson Fluid Systems here in Denver. Eric Quote Link to comment Share on other sites More sharing options...
Zmanco Posted May 5, 2007 Author Share Posted May 5, 2007 Thanks Eric, that's where I bought my helmet. Quote Link to comment Share on other sites More sharing options...
bjhines Posted May 7, 2007 Share Posted May 7, 2007 Just a heads up. you have to be careful when attaching hardlines to something that can vibrate or move even. You also have to consider that the lines can expand/lengthen with heat. Adding U-shaped radiuses and extra bends, as well as using hoses between components and the hard lines can pay dividends in long-term reliabilty. You should not use a compression fitting near the bend in a piece of hardline. The bending method can distort the tubing and make sealing unreliable. You might check up on some of info on the internet about routing and terminating hardlines. Quote Link to comment Share on other sites More sharing options...
Guest ampb5 Posted July 9, 2007 Share Posted July 9, 2007 Check out New Old Stock Motorsports they make cnc bent stainless lines Quote Link to comment Share on other sites More sharing options...
dapiper Posted August 2, 2007 Share Posted August 2, 2007 Watch out for reaction forces near bend where you attach rubber hose. A slip on with several clamps will not hold EFI pressures. Recommend you flare end of tube to form lip to prevent hose slippage. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 2, 2007 Share Posted August 2, 2007 For initial setup, I have used the vapor line on the left frame rail for the return...it's 8mm I believe, same as the stock fuel feed. It may be minutely smaller. I just make a 'Highpoint Loop' with the old vapor line up by the vapor recovery tank, and then vent it out the rear of the vehicle in the area of the right rear tire, like the factory did on some Non-US models (they had a good old 'dump tube' in the filler neck!) My return goes from surge tank, to the 1/4" fitting at the top, right, rearmost highpoint fitting (vent) on the tank. I picked up -6 .035" wall Stainless Steel tubing at the local Swagelock Distributor. Since I have their bitchen' bender, duplicating a factory hardline while it's out of the car is a snap...well, not really a snap---it's really a pain in the butt, but I can (have) do (done) it! Quote Link to comment Share on other sites More sharing options...
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