zeiss150 Posted June 15, 2010 Share Posted June 15, 2010 Hi there! I've been having the worst time trying to find a replacement for the stock gas tank hose. I have a 72 240 and the rear vent hose (thats the big one closest to the bumper) is driving me crazy! I don't want to pay the 80 bucks for a NOS one but I'm starting to think I don't have a choice. I've tried all kids of different ways of running a 5/8ths fuel line and it always kink. The original hose is formed with a 180 degree turn (i think) and if you try that with a straight hose it just kinks on you. I've tried running lots of extra hose to see if I could make a big enough loop and that didn't work. I'm at the end of the line here. Unless someone has found a way to deal with the 240z gas tank hose problems then I guess I'll be buying a NOS hose from motorsport. HELP! Matt- Quote Link to comment Share on other sites More sharing options...
Snailed Posted June 16, 2010 Share Posted June 16, 2010 Hi there! I've been having the worst time trying to find a replacement for the stock gas tank hose. I have a 72 240 and the rear vent hose (thats the big one closest to the bumper) is driving me crazy! I don't want to pay the 80 bucks for a NOS one but I'm starting to think I don't have a choice. I've tried all kids of different ways of running a 5/8ths fuel line and it always kink. The original hose is formed with a 180 degree turn (i think) and if you try that with a straight hose it just kinks on you. I've tried running lots of extra hose to see if I could make a big enough loop and that didn't work. I'm at the end of the line here. Unless someone has found a way to deal with the 240z gas tank hose problems then I guess I'll be buying a NOS hose from motorsport. HELP! Matt- This is just a vent, right? so no real pressure? I'm thinking 1/2" copper pipe is .625"OD so you could just make the part that bends sharply out of a few bucks worth of plumbing stuff and use the 5/8" fule hose you already have to connect it with some clamps. Quote Link to comment Share on other sites More sharing options...
rossman Posted June 16, 2010 Share Posted June 16, 2010 There is a good thread about replacing the vent hoses over at Classic Zcar Club: http://www.classiczcars.com/forums/showthread.php?t=25857 Quote Link to comment Share on other sites More sharing options...
silverarrow27 Posted June 16, 2010 Share Posted June 16, 2010 I didn't want to spend that kind of money on a hose either so I went to the local hose shop and bought the right size. Ran it a little longer with a loop. Worked for me just fine. Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted June 16, 2010 Author Share Posted June 16, 2010 I tried the big loop thing and that didn't work for me. I'll be doing the copper 180 tomorrow. I'll keep this thread updated with the out come. Thanks for the help guys. Matt- Quote Link to comment Share on other sites More sharing options...
two40zjunky Posted June 16, 2010 Share Posted June 16, 2010 Dude go to Kragen Auto and ask the guy behind the counter for the hose coil that keeps hose from kinking. I was going nuts trying to make this weird angle work in the engine compartment of my E36 M3 until I found this little money saver. It cost like $5.00 Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 16, 2010 Share Posted June 16, 2010 Easiest thing to do with those vent hoses is get a 15mm to 10mm Nylon Adapter Fitting, install it at the tank, and then route all the hoses in cheap, readily available and flexible 3/8" fuel line. I have used 1/4" as well. I can pressurize my tank to 5+Psig without a single whiff of leakage. The 510's used nylon joiners and couplers from the OEM, they last forever. This way, you can salvage straight portions (about 2" long) to stick on the tank, and put the adapter right there. Done deal. Sealing the penetrations where the 15mm used to come through the floor was done with some shrink tubine (the kind with glue on it) and some burrer stoppers I had around that were bored to 3/8" hose O.D., razor split, and pushed into the larger holes. Haven't had a problem since. This is VAPOR HOSE. The flows you have are miniscule through it. 10mm will work fine. Some JDM cars only had one vent, and that was a 1/4" dump off the filler neck. We don't need the big fancy braided hoses. Smaller stuff retains 100% functionality. Quote Link to comment Share on other sites More sharing options...
Snailed Posted June 17, 2010 Share Posted June 17, 2010 Easiest thing to do with those vent hoses is get a 15mm to 10mm Nylon Adapter Fitting, install it at the tank, and then route all the hoses in cheap, readily available and flexible 3/8" fuel line. I have used 1/4" as well. I can pressurize my tank to 5+Psig without a single whiff of leakage. The 510's used nylon joiners and couplers from the OEM, they last forever. This way, you can salvage straight portions (about 2" long) to stick on the tank, and put the adapter right there. Done deal. Sealing the penetrations where the 15mm used to come through the floor was done with some shrink tubine (the kind with glue on it) and some burrer stoppers I had around that were bored to 3/8" hose O.D., razor split, and pushed into the larger holes. Haven't had a problem since. This is VAPOR HOSE. The flows you have are miniscule through it. 10mm will work fine. Some JDM cars only had one vent, and that was a 1/4" dump off the filler neck. We don't need the big fancy braided hoses. Smaller stuff retains 100% functionality. Thats a good point. I have always used 5/16" or 1/4" vents with no problems on fuel tanks I have made. It makes me wonder what the idea behind the massive factory vent is. At one point there was a guy, getting paid, that designed the original system. I would like to think he knew what he was doing or that someone that did was checking his work. Maybe there were 10,000 extra hoses that nissan could source for half the price and some poor engineer was told to use them haha! Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted June 17, 2010 Share Posted June 17, 2010 Dude go to Kragen Auto and ask the guy behind the counter for the hose coil that keeps hose from kinking. I was going nuts trying to make this weird angle work in the engine compartment of my E36 M3 until I found this little money saver. It cost like $5.00 Yeah this was going to be my suggestion, but two40zJunky beat me to it. Phar Quote Link to comment Share on other sites More sharing options...
4.6StangRage Posted June 17, 2010 Share Posted June 17, 2010 Yeah this was going to be my suggestion, but two40zJunky beat me to it. Phar check out an RV shop, they got a ridiculous selection of hoses. Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted June 18, 2010 Author Share Posted June 18, 2010 Thanks for all the posts! I went with the copper solution because that was the first one that was posted and it seemed pretty easy. I picked up 2 90 degree elbows and a 1 ft section of 1/2 inch copper tubing. then I just soldered the 90's together and, problem solved. I think I put almost 16 gallons into the tank with no problem. The first time I tried this about 7 years ago I kinked the large vent hose while putting the gas tank up into the car. I could never get more than 9 gallons into the thing. Today was the first time I've ever seen my gas gauge at full! If there is one thing I can count on is that the members here will have an answer for me! Thanks again guys! Matt- Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 18, 2010 Share Posted June 18, 2010 Thats a good point. I have always used 5/16" or 1/4" vents with no problems on fuel tanks I have made. It makes me wonder what the idea behind the massive factory vent is. At one point there was a guy, getting paid, that designed the original system. I would like to think he knew what he was doing or that someone that did was checking his work. Maybe there were 10,000 extra hoses that nissan could source for half the price and some poor engineer was told to use them haha! "Captive Volume based on vapor pressure." I don't even want to get into safety factors, flows, and crap like that, but there is a rationale for the larger sizes when venting volative fluids. But like most stuff Nissan Did, it was 3X overdone. Engine Blocks that routinely last 300K when they can run 100K and at the time be overhauled (and people would accept it as normal, especially the British...) Take a look today at vapor transfer hose and see what the maximum size you have! Quote Link to comment Share on other sites More sharing options...
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