Sparky Posted November 23, 2001 Share Posted November 23, 2001 hey guys! first time posting and hope yall can help me out. ive asked this question on Zcar.com as well as bimmer.org...and got a response of 50/50, so hopefully someone here can clear it up with real information. I stopped by the local FI shop (fuel injection specialties in San Antonio) and told them what i was doing. also showed them some aluminum line i had lying around. i felt the the alum line wasnt going to fit the bill...and they agreed on that...they told me to go with steel brake lines and use rubber hose for the flexy bits and curves. although i know that the steel would work, i have a problem with running a lot of rubber sections in a long bendy leanght of high pressure fuel line. (the less joints and fittings you have, the less chances of a leak are). so i asked about copper line, the type you buy at home depot for high pressure natural gas lines and refrig. lines. the main guy there thought about it for a bit and from his knowledge he could not think of a reason that copper would be a poor choice (now if it was thinner water line type tubing he said that it could annurism at high pressure). ao anywho! all opinions welcome...please help me solve this problem...!! laterZ Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted November 23, 2001 Share Posted November 23, 2001 Copper works. It was used for years in the early days of cars. Steel is used now because it is cheeper. I used aluminum, no problem there either and I'm running a tpi motor. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 23, 2001 Share Posted November 23, 2001 Hrm, I dunno'. Copper can work harden can't it? Vibration on a stiffly mounted piece of copper like that could be trouble. Heavier piping like gas pipe might be okay but water pipe for sure would be bad - glad you've ruled that out. Even the aluminum stuff would make me nervous for EFI use to be honest. I've always used braided line and adel clamps with AN fittings but it's a bit expensive for all those fittings... Quote Link to comment Share on other sites More sharing options...
Sparky Posted November 23, 2001 Author Share Posted November 23, 2001 can someone explain "work harden" to me? also the tubing will have the stock rubber isolators in use ....i know it will still get vibration and what not...but its not like im mounting it to the body itself. i dont know. whatdaya think? laterZ Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 23, 2001 Share Posted November 23, 2001 Some metals will harden as you bend and manipulate it. Aluminum sheetmetal usually has to be annealed to get it soft for working and often re-heated to soften it again, as working it by stretching and shrinking makes it hard again. Copper I believe is one that does harden, I'd be concerned using it on a modern car with the fuel pressure they run now. In a old model T, yeah probably work fine. But then again I'm not even crazy about aluminum, even though it works fine. Paranoia Will Distroy Ya... Regards, Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 23, 2001 Share Posted November 23, 2001 Yes it will work, the effects of work hardening should be negligable as long as its secured properly along the full length of the body so it doesnt move and flex, the same would happen to aluminium and steel anyway. Take the usual precautions ie dont pass the line through the bodywork without using gromets try not to pass it under cross members try to maintain a barrier between the line and the road, ie. the side rails and dont have it to close to the exaust for the obvious reason and because i have seen it cause vapour lock (if this is EFI then the high pressure should stop this anyway). But if you have to buy new line anyhow why wouldnt you just use steel its proven to be suitable and its probably cheaper. Quote Link to comment Share on other sites More sharing options...
Guest scca Posted November 23, 2001 Share Posted November 23, 2001 why dont you just get the steel in a coil length? its available in 25'length packages so you just install it as one piece. you'll have a bit left over but its not that much for a roll anyway. Quote Link to comment Share on other sites More sharing options...
Supra510 Posted November 23, 2001 Share Posted November 23, 2001 I have used the steel brake line with no problems on my efi 510. You can buy it in various lengths and you can buy couplers if the lengths are still too short. The rubber hose used to connect the steel line to the fuel rail and out of the fuel pressure regulator are very short. I have had no problems with this set up. Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted November 24, 2001 Share Posted November 24, 2001 I ran 3/8" aluminum through the original rubber mounts. I did this after the motor, tranny and drive shaft were installed. It was very difficult. It would have been imposible with steel. If you have everything out than you can probably do it in steel without a problem. Copper doesn't work harden. I'm an A/C mechanic and work with copper tube every day. A/C systems vibrate like crazy. Very, very rarely do you find leaks from fatigue. What you find is abration leaks. If you have it mounted in rubber, no problem. Also, FI pressures are no way near the limits of copper tube. A/C systems normally operate at 250 to 300psi. I've seen pressures as high as 500psi. Any of the three materials will be more than adequate. More important will be the quality of the instalation. Quote Link to comment Share on other sites More sharing options...
Sparky Posted November 24, 2001 Author Share Posted November 24, 2001 thanks for all the info guys, What i need to do is find a place in SA where i can buy some steel tubing in a coil, and compare to the copper price...i know that 1/2 inch copper tubin in a 25 foot roll is 19$. thats the main reason why i was looking at copper....its cheap...its easy to bend...and i can get it les than a mile from my house. budget budget budget. i still have 7 months to finish my car and im at 50% right now. ive been at it for 6. laterZ Quote Link to comment Share on other sites More sharing options...
Mike C Posted November 25, 2001 Share Posted November 25, 2001 Aluminum is far worse about work hardening than copper. Copper is not allowable for fuel by any sanctioning bodies. I don't know if it is an electro-mechanical relationship or a chemical problem with fuel. Either way, DON"T RUN COPPER FOR FUEL. Check with somebodies tech line (Holley/Autometer) For exact reason. Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 26, 2001 Share Posted November 26, 2001 I've also heard that copper reacts with something in the gasoline to cause problems. I'd stay away. I'd go with brake tubing, either steel or stainless steel. http://classictube.com can sell it, and put fittings on it if you like, for example. Quote Link to comment Share on other sites More sharing options...
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