Plastic Tunnel Fuel Lines, I want to replace the 2 tunnel fuel lines in my 76 - 914 Options

[matchpoint]

I have my 76 - 914 engine and fuel tank out of my car during my frame off restoration. I want to replace the 2 plastic/nylon fuel lines in the tunnel with an OE product and not use the stainless or mild steal fuel line. I want to go back original and after 40 years of service I want to replace the plastic lines. Looks like everyone says go stainless but I want to go with the OE plastic.

Does anyone have a part number of a replacement plastic/nylon tubing of the same size as the OE plastic tubing. I think it is 7MM OD size. Auto Atlanta told me to just blow out the OE plastic lines and don't waste your time replacing. Looks like an easy replacement while the car is apart and all I need to know is a P/N of a plastic/nylon fuel tubing I can get @ NAPA.

Thanks

[napasteve]

I'm having a hard time understanding why you wouldn't use SS lines. My OE plastic lines shrank and I had fuel leaking in the engine compartment. Not good. I'm not sure OE plastic lines were designed for today's fuel (Ethanol???).

[JeffBowlsby]

OE fuel lines are NLA. The 1970-74 lines are nylon, but the 75-76 cars use a different material that is the best Porsche made at the time and they are very good quality. Unless yours are damaged they probably do not need replacement.

Nothing wrong with the stainless lines either.

[Gunn1]

Try the search function

There is mucho info on installing and folks that supply them.

[914Sixer]

Bel-Metric has the new version of the fuel line you are talking about called polyamide. Cohline is the manufacturer of the stuff. $9.01 a foot over 5 feet (8mm)

[mepstein]

Makes sense not to use the best product available to carry gasoline into the engine compartment. Right? Especially a high dollar restoration. (IMG:style_emoticons/default/confused24.gif)

[pete000]

This is the one part I would not want "Factory Correct" Those points deducted from the judge aren't worth it. Unless the car is not driven outside of the lawn of the show only...IMHO Go Stainless !

[green914]

Pelican Parts has the how to instructions for replacing the fuel lines with ss lines on their web-site.

[JawjaPorsche]

If I was making an investment like you are, why take a chance on a fire. Go with stainless.

[JeffBowlsby]

"Polyamide" is the larger family name for Nylon. Glad to see its also available in black for the 75-76 cars.

[matchpoint]

"Polyamide" is the larger family name for Nylon. Glad to see its also available in black for the 75-76 cars.

Hi Jeff,
Thanks for your reply to my search for OE replacement plastic tunnel fuel line for my 914. I have the car apart and want to replace the 40 year old plastic fuel pressure and return line. Everyone seems to say use stainless tubing but I want to go back OE. I found Bel Metric on the internet has the hose. Looks like it is $8.25 per meter. I think it is a German MFG called Cohline. They say their hose is 8MM OD & 6MM ID which should work. From what I can tell I would need 32 feet. I want to use the plastic for 3 reasons. The OE has lasted 40 years. I want to go back to the OE black plastic look where the 2 hoses that come through the engine shelf are plastic and are one continuous stick all the way to the front firewall. The important reason is I want to keep hose clamp/rubber line joints to a min. and the 4 section stainless system that Tangerine offers would introduce 4 clamps to seam the sections together.

I will search the internet for another US mfg who offers polyamide. Let me know if you have a P/N for a US mfg or supplier. I think Imperial may make the hose also.
Thanks
Bob

[barefoot]

http://www.parker.com/literature/Parflex/B.../CAT%204660.pdf

Go to page B20 look around
There are Parker stores to buy from
Barefoot

[JeffBowlsby]

It will take some workmanship care and research to get these right using nylon. The nylon tubing can be bent with heat and a thick copper wire inserted into it to minimize ID collapse. OEM lines include a section of metal tubing up near the brake pedal area, you will probably just want to run the nylon full length through the tunnel.

Check the ID/OD...I believe you need a ~10mm OD for the supply.

Last I checked, McMaster carries the white nylon for a true OEM look for the 2 tubes the come through the engine shelf by the battery...its very cool to see new engine bay lines and watch the fuel flow through them. They are whitish translucent...but not opaque.

Give up on the idea of a single tube front to rear, it would be too complex. The fuel pump area disrupts the tubing continuity anyways and rubber hose/clamps are OEM.

[Catorse]

They used asbestos for decades and lead for centuries. Just because it lasted doesn't mean it was the best material to use.

The plastic lines are a safety issue, plain and simple. Yes, I already replaced mine.

[JeffBowlsby]

The plastic lines are a safety issue, plain and simple. Yes, I already replaced mine.

What basis do you have for that opinion other than anecdotal and is it a unilateral or conditional opinion?

Automotive engineers certainly had metal tubing available for fuel lines in the 1970s, they chose nylon intentionally and it met federal safety standards at the time of manufacture. Not saying they are not a maintenance item and may require replacement from time to time as good practice, but your unequivocal statement is not substantiated. I can think of a few disadvantages of metallic tubing over nonmetallic tubing for fuel lines, its not as slam-dunk as some think.

[mepstein]

I would think the chance of it getting nicked by the shift mechanism inside the tunnel and sourounded by the 45 year old wire harness makes the ss lines the right choice. Might never happen but who knows. I know if it did it would be my car.

[Mueller]

Nylon tubing for fuel is approved for aircraft use, not saying that is the end all to the discussion, just something to think about.

http://www.aircraftspruce.com/catalog/appa...lickkey=3011511

[napasteve]

Jeff,

I just replaced my OE metal/plastic lines that run thru the tunnel and the plastic lines that run from the below the engine shelf to above with SS lines from Tangerine. The leak I experienced before the change was above the engine shelf where the clear plastic line was inserted into a rubber line to feed the injectors. Seems like that OE clear plastic line kept shrinking and I had to keep tightening the clamp to prevent leakage. I think I was really lucky that I didn't have a fire. My car is a '73; I'm not sure if lines in a 1976 are the same.

So my question is: do you think I made a mistake going to SS?

I have a chemistry background. There are a ton of different plastics out there, each with different characteristics and interactions with the various components in fuel. Lifespans will vary. SS, on the other hand, can sit in any fuel with any additive(s) for 1000 years and will not degrade one bit.

I can understand the desire for OE AMAP. It's kind of cool to have a timecapsule; I think it's one of the things that binds 914World members. It just seems to me that SS is WAY more durable (and therefore safer) than the OE lines and they are not that expensive or difficult to install.

[Catorse]

Whoaa......are we saying the 914 has AIRCRAFT QUALITY NYLON in their for fuel hose? Yeah, I don't think so. Looks like old ass plastic to me. I am well aware of the advances made in polymers today, but we are talking about the stuff already IN the car.

Jeff,

You need to remember that the "automotive engineers" always did answer to automotive bean counters. The 914 was a budget model. Premium products were not used in its manufacture. I am guessing the 914 has plastic lines because they were cheaper, not better. Certainly cheaper than stainless.

My 911s of the same era have metal lines. What does that tell you about what Porsche thought???

[Amphicar770]

If you want to have original hoses because you think things like original motor oil are important, then that is your choice. Trying to argue that it is "better" because that is what came from the factory is nonsense.

Of course metal lines were available back in the 70's. So was gold wire. They did not choose plastic (or copper) because it was better but much more likely because Otto in accounting figured it would save $3 per car or Hans in manufacturing determined that it could be installed 3 seconds faster. Every cent counts in mass production.

Yes, some aircraft use plastic lines but they are also subject to a level of annual and other inspections that go far beyond what even the most anal car owner is accustomed to. Every part has a lifespan rating and is replaced regardless of condition.

If you do stick with plastic lines that is great. Just make sure to have a non-original fire extinguisher in your car.