fuel line replacement material choice, that factory hard plastic line Options

[dmenche914]

From the fire wall to engine, I'd like to select a good replacement for the brittle plastic line that was factory. what material is it? Nylon? It's got to be chemical, and heat resistant. i'd like something that looks original. Mine is all yellowed, I assume it was originally a white translucent color.

Any ideas on a good tube, and source thereof?

thanks

Dave

[SpecialK]

I believe that most people replace them with 3/8" steel brake line tubing, but I've also heard of soft copper tubing used in HVAC (most dislike this choice (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) ). A pretty good selection of fuel line tubing can be found at:

http://www.aircraftspruce.com/menus/ap/tubing.html

I personally went with the steel brake line tubing....relatively cheap, and easy to bend with the proper tool.

[SirAndy]

QUOTE (dmenche914 @ Jan 25 2005, 10:22 AM)

I assume it was originally a white translucent color.

they all have the slight yellow tint to them. if it's brittle, you should consider replacing the whole line, not just cut it off at the firewall.

the 2 easiest choices are:

- get a set of good original plastic fuel lines from a donor car.

- convert to aftermarket metal fuel lines (don't use copper lines!).
you can buy them ready to go (already bend correctly and everything)

the only problem with replacing the whole crap-o-la is that it requires to drop the engine and remove the tank.

you *might* be able to do it with the engine in the car, but it'll make the job a nightmare ...

(IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) Andy

[BigD9146gt]

I'm a few weeks away from completing this kit, and 95% sure you don't have to drop the engine either. Only take off the right rear wheel. Next week i will install a kit on a 9146gt replica with the quick 6 engine mount to get an actual feel for install time and tricks. The kit will run about $200.

http://www.914world.com/bbs2/index.php?act...=ST&f=4&t=24154

[Dr Evil]

I believe that the original material is polycarbonate. You could probably source it at McMaster-Carr (SP). I used full steel from tank to fuel rail. It looks nice when done right.

Why not use copper?

[drgchapman]

Who makes said ss fuel line from front to rear? Someone said it is formed as well?

Gary

[SpecialK]

QUOTE (Dr Evil @ Jan 25 2005, 03:28 PM)

I believe that the original material is polycarbonate. You could probably source it at McMaster-Carr (SP). I used full steel from tank to fuel rail. It looks nice when done right. Why not use copper?

Some people were led to believe that copper will "work harden" and crack because of vibration.....22 years in the HVAC biz tells me that they're over reacting. Residential air conditioning systems vibrate constantly, with pressures in excess of 300psi at times (hot day), and withstand yearly removal and installation of the "A" coil (which requires bending the lines) for cleaning for 20 years or more with out any leakage of any kind in the lines themselves. Not to mention that there would be rubber lines connected at each end, isolating the copper lines running through the tunnel from most, if not all vibration they would encounter.

The sky is falling!....the sky is falling! (IMG:http://www.914world.com/bbs2/html/emoticons/hide.gif)

[Dr Evil]

I'm with you Kevin. Even hard copper tube used for plumbing water will become permenently softened and maliable when heated red hot. the soft stuff should be just fine. IMHO.

Gary,
you just need to use SS break lines from your FLAPS. There is/was(?) an article on such on the bird board. It si the one that I followed. The hardest part was combining the fittings to make a 90 degree turn when the pipes exit the fire wall. Not exactly necessary, but I wanted the lines to be hard all the way untill they exited the engine shelf. I spent $40 approximately on the whole set up including the bender that is pictured in Biggie's link. I can take pictures if you all want as both ends are currently exposed (no engine, no tank).

[lapuwali]

There's a tech article on our very own board about installing SS fuel lines into the tunnel.

[ClayPerrine]

QUOTE (Special_K @ Jan 25 2005, 06:23 PM)

QUOTE (Dr Evil @ Jan 25 2005, 03:28 PM) I believe that the original material is polycarbonate. You could probably source it at McMaster-Carr (SP). I used full steel from tank to fuel rail. It looks nice when done right. Why not use copper? Some people were led to believe that copper will "work harden" and crack because of vibration.....22 years in the HVAC biz tells me that they're over reacting. Residential air conditioning systems vibrate constantly, with pressures in excess of 300psi at times (hot day), and withstand yearly removal and installation of the "A" coil (which requires bending the lines) for cleaning for 20 years or more with out any leakage of any kind in the lines themselves. Not to mention that there would be rubber lines connected at each end, isolating the copper lines running through the tunnel from most, if not all vibration they would encounter. The sky is falling!....the sky is falling! (IMG:http://www.914world.com/bbs2/html/emoticons/hide.gif)

The wrong kind of copper will work harden. All copper lines will flake internally when exposed to the additives in gasoline. BTDT. Not fiction. I saw this in person and had to replace the lines.

[scruz914]

QUOTE (Special_K @ Jan 25 2005, 05:23 PM)

Some people were led to believe that copper will "work harden" and crack because of vibration.....22 years in the HVAC biz tells me that they're over reacting.

I think the point was concerning copper's reaction to gasoline.

QUOTE (ClayPerrine @ Jan 24 2005, 06:09 AM)

.....the soft copper lines sold in hardware stores for water lines will start flaking internally when exposed to gasoline.  BTDT.

[SpecialK]

"Fuel lines, which connect all the units of the fuel system, are usually made of rolled steel or, sometimes, of drawn copper. Steel tubing, when used for fuel lines, is generally rust proofed by being copper or zinc plated."



http://www.partsamerica.com/Auto101fuel.asp#FuelLines

I guess we agree to disagree then (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[Dr Evil]

QUOTE

I guess we agree to disagree then

No we don't (IMG:http://www.914world.com/bbs2/html/emoticons/tongue.gif)

[anthony]

The question should be whether the original fuel line really is brittle or damaged. I think lots of people replace this line "just because". They think it's a good idea and that because the line is 30 years old failure is imminent.

If the line isn't damaged just leave well enough alone and work on a different project.

[Dr Evil]

QUOTE

The question should be whether the original fuel line really is brittle or damaged. I think lots of people replace this line "just because". They think it's a good idea and that because the line is 30 years old failure is imminent. If the line isn't damaged just leave well enough alone and work on a different project.

I gotta agree with Anthony on this one. My lines wer 30 years old, but they were hard as hell to cut and were not brittle at all so they didn't need replacement. However, I wanted to have stainless anyway because they are cooler. Well that and I suffer from autohypochondriasis. (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[anthony]

I actually asked Brad a while ago if I should replace mine and he said that it wasn't a common failure and that he usually replaces damaged lines with good used 30 year old lines from parted out cars.

[JFJ914]

QUOTE (Dr Evil @ Jan 25 2005, 07:28 PM)

I believe that the original material is polycarbonate. You could probably source it at McMaster-Carr

Actually, the original fuel lines are made of Nylon 11. McMaster has it in the correct metric sizes, 8 and 10 mm OD IIRC.

[Rhodes71/914]

I considered replacing my plastic lines as well since I had the engine out and doing some rust repair. While I was moving the lines out of the way to do some cutting and grinding I checked them out pretty good and came to the conclusion that they will stay.

What's been said here gives me faith it was a good decision.

Sean

[Trekkor]

My boat has a copper fuel line from the pump to the carb, a copper heat exchanger and a copper fresh water oil cooler. No leaks. Since 1977.

I like copper. (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif)

KT

[BigD9146gt]

QUOTE (Special_K @ Jan 25 2005, 04:56 PM)

"Fuel lines... is generally rust proofed by being copper or zinc plated." http://www.partsamerica.com/Auto101fuel.asp#FuelLines

If i may add something,

The part thats being assumed is the plated part. These are externally plated, not internally. Even the Cohline (Porsche OEM) tubes that i'm using in my kits arn't internally coated. They're refurring to exterior rust, not internal. Even a gas tank thats been sitting for 30 years with gas will have very little rust below the gas line, but above its really bad. Most of the rust below the fuel is due to rust flakes above the fuel line dropping in, and with sloshing of the gas, oxiginated gas supplies the rust.


In my kit, the flex line connectors, crimps, and cap nuts are fully cad 2 (zinc) plated because they are smaller and are easier to dip into complete solutions, whereas tubing is manufactured is long lengths and externally washed through the solutions.

Also keep in mind the hundreds of alloys that are on the market. Just because one application has used copper, doesn't mean that any copper will work. With a little bit of research, you can figure out why you will find it in some parts and not in others.