dpuma8 Posted November 9, 2011 Share Posted November 9, 2011 I have the 3/8 hardline under my car right now and I have seen that some people have welded in 6 AN fittings into the gas tank. Is this necessary to do or recommended? I have a surge tank mounted. Is AN fittings and braided fuel line a good upgrade or is it mostly for show? I don't care to have braided fuel lines if rubber lines is good enough. Any thoughts about it? Quote Link to comment Share on other sites More sharing options...
rossman Posted November 9, 2011 Share Posted November 9, 2011 For a street car, AN fittings are not necessary. Quote Link to comment Share on other sites More sharing options...
rossman Posted November 9, 2011 Share Posted November 9, 2011 Oh, and -6 AN is approximately the same ID as 3/8 tube. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted November 9, 2011 Share Posted November 9, 2011 I have earl's 6an push-lok hose on my tank-it slides right on then put a hose clamp on it.There isnt any pressure at this spot. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted November 9, 2011 Share Posted November 9, 2011 Are you experiencing any fuel starvation problems? If not, then no, you don't "need" to change the fuel line size. Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted November 9, 2011 Author Share Posted November 9, 2011 I have my car in pieces right now so I am planning on building for the future. Before I tore it apart, the engine was stock and I did not have fuel starvation issues. The 3/8 hard fuel line is already under the car. I don't want to do AN fittings if it is not necessary or that much of an improvement over regular fuel hose. I want a higher HP car. Do I need to modify the stock gas tank inlets/outlets for the larger fuel line I will be running? Quote Link to comment Share on other sites More sharing options...
rossman Posted November 9, 2011 Share Posted November 9, 2011 I would say that you need to size the tank fittings to the tube size. Tube size should be determined by engine power and pump requirements. I'm my case the pump I chose drove the tube sizing. I'm using an Aeromotive A1000 fuel pump that requires 1/2" ID fuel line so I used 5/8" tube, -10 fittings and 1/2" NPT tank fittings on the feed side. That will be more than enough for my power range. Quote Link to comment Share on other sites More sharing options...
h4nsm0l3m4n Posted November 9, 2011 Share Posted November 9, 2011 How much HP are you planning on? I run 3/8 lines for my LS1 swap (350 hp) with a surge tank and dont experience any fuel related issues. 3/8" line ought to support at least 500 hp, maybe more. It may not look as fancy but regular fuel hoses and fittings work just as well as AN fittings. Your car wont go faster if it has AN fittings on it. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted November 9, 2011 Share Posted November 9, 2011 You should up-size you fuel pick-up line to 3/8" if you are planning to make more power than stock. Keep in mind the fuel pick-up is on the suction side of the pump which makes it more sensitive to restriction issues since you cannot overcome the restriction with more pressure like you can on the engine side of the pump. Any good welding shop should be able to replace the original fuel pick-up with a 3/8" line. Copy the shape and length of the original. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted November 9, 2011 Share Posted November 9, 2011 I still have the stock fuel lines on my 280Z, 5/16". Put a good pump behind it, and you shouldn't have fuel starvation issues, at least to 350hp. Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted November 9, 2011 Author Share Posted November 9, 2011 I am looking for maybe 300 hp. I have a Carter low pressure pump feeding into a surge tank and then the Walbro high pressure pump feeding the injectors. I am not going to go crazy on my build since it will never see a track. I am still not clear on if I would need to have bigger fitting welded on my tank for 300hp. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted November 9, 2011 Share Posted November 9, 2011 I think your answer is no. You already have larger lines than factory 5/16", are you sure they are 3/8"?. You can do 300hp with the Walbro alone, mounted by the tank. Fuel line upgrades on the Z typically are for 240 conversion to fuel injection, and the surge tank is used because the 240 tank was not baffled. If you have a fuel injected 280Z, you don't need anything special unless you are doing some serious racing or making power in excess of 400hp. You'd be surprised how little pressure drop you get with factory line running 60 psi from the tank. I ran some calculators and determined the pressure drop for these flow rates is less than 1 psi. The Walbro can deal with that. Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted November 10, 2011 Author Share Posted November 10, 2011 Right on! Thanks a ton for the replies! I did buy 3/8 line from JEGS with a flaring tool and the line was considerably bigger than stock. If I knew the fixes were mostly were for the 240Z, then I could have saved some money but oh well! Quote Link to comment Share on other sites More sharing options...
voong413 Posted November 10, 2011 Share Posted November 10, 2011 Hey guys, I have a similar question regarding my l28et swap. Is the fitting on the 240z tank big enough to supply fuel to the surge tank? I would drop the tank and have a welder weld bigger fittings, but its hard to find a welder who would actually do that. Quote Link to comment Share on other sites More sharing options...
tyler031734 Posted February 11, 2012 Share Posted February 11, 2012 Hey guys, I have a similar question regarding my l28et swap. Is the fitting on the 240z tank big enough to supply fuel to the surge tank? I would drop the tank and have a welder weld bigger fittings, but its hard to find a welder who would actually do that. I would think any welder would do what I do. Fill the tank with water and weld away. Find a 75-76 gas tank and get the straps with it. Then your good to go. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 11, 2012 Share Posted February 11, 2012 I'll weld on a fuel tanks but I first send it to the local radiator shop to have it flushed. Did the water thing once and got a big WHOOSH out the filler tube when I started welding. Water is not a cleaning agent or a solvent with gasoline. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted February 11, 2012 Share Posted February 11, 2012 (edited) I installed 3/8" fuel line with my EFI/turbo swap, I used the original feed as the return. I upgraded the feed from the tank, but without welding or removing the tank from the car, what I did was replace the drain plug with a 90 degree to flare fitting, 3/8" on both sides. It did require running an NPT tap into the fitting to get a good seal. 3+ years later still great and no starvation issues. Edited February 11, 2012 by Six_Shooter Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 12, 2012 Share Posted February 12, 2012 I'll weld on a fuel tanks but I first send it to the local radiator shop to have it flushed. Did the water thing once and got a big WHOOSH out the filler tube when I started welding. Water is not a cleaning agent or a solvent with gasoline. When I went to fab class back in the 1980's the instructor used an interesting purge method that he'd been using since the 50's to purge gas tanks: He would simply hook a flexible piece of tailpipe tubing to the filler neck, leaving all the other openings open, and the other end went to the nearest car in back lot he could start and idle. After about 30 minutes with gloved hands he would bring the tank in and begin the repair demonstration. I've used it since that time and have never had a backflash in the tank. Have had condensate form in them, but with a quick dump out an orifice the residual heat in the tank's metal would flash off any remaining moisture fairly quickly. And now to think about it, it really is a generally decent inert gas atmosphere I guess...if a TIG or MIG was your goal. But I'd still back-purge properly. The exhaust-purge on tanks was so simple! I'm surprised more don't think about it. Quote Link to comment Share on other sites More sharing options...
Noddle Posted February 13, 2012 Share Posted February 13, 2012 (edited) When I went to fab class back in the 1980's the instructor used an interesting purge method that he'd been using since the 50's to purge gas tanks: He would simply hook a flexible piece of tailpipe tubing to the filler neck, leaving all the other openings open, and the other end went to the nearest car in back lot he could start and idle. After about 30 minutes with gloved hands he would bring the tank in and begin the repair demonstration. I've used it since that time and have never had a backflash in the tank. Have had condensate form in them, but with a quick dump out an orifice the residual heat in the tank's metal would flash off any remaining moisture fairly quickly. And now to think about it, it really is a generally decent inert gas atmosphere I guess...if a TIG or MIG was your goal. But I'd still back-purge properly. The exhaust-purge on tanks was so simple! I'm surprised more don't think about it. You should write a book on all this useful information that is held in your head, I have a text file that I copy this stuff into, with the link to the source, and grouped into topics for easy finding, You do have a wealth of information, but some time it I find it hard to understand when you are been crypted about what you saying, especially when you start referring to 'sheep' lol Nigel Edited February 13, 2012 by Noddle Quote Link to comment Share on other sites More sharing options...
sdm9785 Posted February 15, 2012 Share Posted February 15, 2012 Alright, Question. I've got a 75, I know it has one of the more sought after factory tanks, but how will it do on light track days? L28et with 3 to 400 hp is what it will be supplying. Quote Link to comment Share on other sites More sharing options...
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