copper+gas

[jusbo]

I got a new sending unit for my gas tank (stock) and was going to use copper tubing in place of the intank pump (got an external holley blue). Will the copper get corroded by the gas or leak impurities?

[Scotty_S-15]

Watcha mean, "leak impurities" http://www.s10v8.com/images/smilies/icon_confused.gif



But yes, good question. Copper was used for gas lines forever without problems. BUT, with today's new gas blends, who knows. If it were me, I'd use steel brakeline stuff available at most Auto Parts stores.

............. Part of the problem with the gas today, is that with the ethanol additives, water is readily absorbed in the gas, and can interact with whatever it comes in contact with. http://www.s10v8.com/images/smilies/icon_frown.gif

[355V8S10Tahoe]

I have used 3/8" copper tube and a copper housed 100 mesh liquid line screen like the ones used in a central air unit three times now and never had a problem with it... The copper filter screen housing when cut off at one end has a perfect diameter to install the stock fuel pickup screen, in the event that the stock pickup screen deteriorates or falls off, the stainless 100 mesh screen will remain as a safety backup... Here is a couple pictures of the one in my 87 long bed...





<hr width='200'><img src='images/jpg.gif'>: <a href="http://s10v8.com/members/355V8S10Tahoe/FuelPickup2.JPG" BORDER="0" target=_blank><font size="-2">image will open in new window</font></a><hr width='200'>




A little closer...



<hr width='200'><img src='images/jpg.gif'>: <a href="http://s10v8.com/members/355V8S10Tahoe/FuelPickup1.JPG" BORDER="0" target=_blank><font size="-2">image will open in new window</font></a><hr width='200'>




On the subject of corrosion, on my 88 short bed (the one that got flipped) I used copper line to run a fuel line from the drivers side fuel hose connection at the frame all the way around the front under the radiator support to the mechanical pump on the engine (passenger side)... When I salvaged the truck I found that the copper line had started corroding on the outside but it looked almost shinny new on the inside, looking at the pump delete pipe I had in that tank, it looked just like it did when I put it in there... I think the Florida salt air is what really attacks copper, battery acid and antifreeze is not good either but gas has a very slow effect on it if any, I don't know about ethanol though, Iv,e never run that...

[Scotty_S-15]

Great pix, Tahoe. Gotta love a guy who documents everything, a great help to all.



And, waiting for some experts to check in on the consequences of new gas blends on different metals.



Just because I mentioned that the use of copper fuel lines is "questionable" with the new gas blends, doesn't necessarily mean that aluminum lines are any better. We've all probably had experiences with what the newer gas blends does to the carbs on our lawn mowers, snow blowers, etc. Seems to make a mess in some alum. alloys.



The steel lines with whatever plating they use seems to hold up, as long as the plating was done properly.



Neoprene? How does that hold up with high alcohol concentrations?



Teflon lined hoses has to be AOK, right?

[jusbo]

On 2008-02-23 10:34, Scotty_S-15 wrote:



And, waiting for some experts to check in on the consequences of new gas blends on different metals.





LOL!!! Humor! Ok, that is some EXCELLENT work there Tahoe! I didn't even think about doing it like that. I could cut a piece of the aluminum fuel line that came in my kit...its 3/8" then find some way to attach the screen.



On the same topic here, how would one plug the return line?

[355V8S10Tahoe]

Thanks for the nice comment jusbo, as for plugging that return line, on two of my S10's I just took a short piece of 5/16 fuel line plug it on one end with a steel dowel or unthreaded bolt shank and a couple hose clamps but on my most resent 87 S-truck I went one better and also shoved a ball bearing inside the return hose that attaches to the gas tank, so I have two plugs... I did this because I had a scary trip one night to the inlet to fish, I had just went and filled up the gas tank then went fishing, when I got there I was smelling gas and was wondering if it was me, well I got out and noticed a gas puddle forming by my left front wheel, I popped the hood and discovered that the cap I had on the return line hose bib at the frame was cracked and was leaking, at that time I didn't have a plugged piece of fuel line hose, it was a Chinese rubber vacuum cap, that was a big mistake... Anyway I actually drove it right back home about 3 miles thinking it was going to go up in flames any minute, but I made it and stuck a pan under it to catch the gas, I never want to do that again... http://www.s10v8.com/images/smilies/icon_eek.gif

I guess the best way would be to crimp the return hose bib shut at the sending unit and braze or solder it permanently shut, but I didn't want to make it non reversible if I ever wanted fuel injection again...NOT! http://www.s10v8.com/images/smilies/icon_cool.gif I hate in-tank electric fuel pumps...

[355V8S10Tahoe]

No I didn't forget you Scotty, Thanks, and yeah I think steel line is the best to use and Teflon? I would think would be great also but what would that be, a Teflon coating, I made a new setup for my cross over fuel feed tube that runs from the drivers side to my mechanical fuel pump on the passenger side of the engine, it was a specially coated steel line for corrosion resistance (from Autozone), I wonder if that was Teflon? It was gray in color and tough as hell... The tube I made bolts to the engine and runs in the gap between the back side of my harmonic balancer and the front nose of the oil pan, the mounting tabs I made for it are welded to the tube so it can't slip or move, that could be a dangerous situation if it did... Here is a picture of it...



<hr width='200'><img src='images/jpg.gif'>: <a href="http://s10v8.com/members/355V8S10Tahoe/F-PumpFeedLine.JPG" BORDER="0" target=_blank><font size="-2">image will open in new window</font></a><hr width='200'>




I don't have a great picture of it on the engine but in this next one, on the upper left side you can see it running behind the 8" balancer...

<hr width='200'><img src='images/jpg.gif'>: <a href="http://s10v8.com/members/355V8S10Tahoe/FuelFeedLine2.JPG" BORDER="0" target=_blank><font size="-2">image will open in new window</font></a><hr width='200'>




I think it turned out nicely and I haven't had any vaper lock problems with it either, it seems to be cooled by the spinning harmonic balancer... http://www.s10v8.com/images/smilies/icon_wink.gif

[jusbo]

quick question about the placement of the external pump....I know it should be close to the tank, but should it be:



High above

Equal to the tank

Lower than ?



Edit that, I found an answer