How difficult is it to change the plastic fuel lines out with the engine in the car and how crucial is the material the line is mad of? Is it critical to use stainless, or just a very good idea?

Why? Is yours broken or leaking? Other than the area between the engine and the firewall, I've never seen one fail. (32 years and counting.) The Cap'n

It can be done with the motor in the car. It just makes it a little tougher and probably require a 2 piece run. I used 3/8th stainless on mine but Summitt has some nice aluminum line if you're into that instead.

QUOTE (Cap'n Krusty @ Aug 26 2005, 06:03 PM)

Why? Is yours broken or leaking? Other than the area between the engine and the firewall, I've never seen one fail. (32 years and counting.) The Cap'n

31 is about right for a 110 pound blonde, but kinda old for a piece of plastic. I am getting an orange '74 2 liter next week and plan to change out the fuel lines under the gas tank, the plastic that runs trough the tunnel and all the rubber hoses under the hood. I know it will be a pain in the ass, and I always carried a fire extinguisher in the bug, and plan to carry one in the Porsche, but I don't want someone waving at me at a stop light yelling about my car dripping something, right before I burn to death, or worse yet, almost to death. Call me paranoid.

Stainless, mild steel, aluminum or OE plastic. Take your pick.

I woulnd't do copper, heard that it can work harden and crack (however, I don't know how much it may do that in this application).

Aluminum will be a little softer so you will have to watch for kinks more than steel.

Stainless will be the toughest to bend.

I used 5/16 brake line (mild steel) and replaced it with the engine in the car. I had to do one section through the tunnel, a short piece of FI hose in between, then hoses into the engine compartment.

best stuff I found to use, and it is plastic is near identical to the OEM fuel line. It is sold mail order by Mc Master Carr 9630 Norwalk Blvd, Santa Fe Springs, CA

for the small diameter tubing (early verses late cars had two sizes of plastic tubing) I ordered 25 feet of part number 5548 K53 This material is made of Nylon 11 which is supposed to be supperior to the Nylon of 30 years ago. this tubing is 5/16 inch od, with .035 inch wall thickness. This is so close to the metric equivelent used in the 914 that you can't tell the difference in fit. It is the "perfect" replacement. Since I only replaced the line in the engine bay (which has the hardest life from heat, and battery acid (sulfuric acid is death to nylon) I only ordered the smaller diameter. If I did the tunnel in my car i would have ordered the the other size also.

cost is 50 cents per foot, with shipping the total for me was $18.07 for the 25 feet. ( I have more than enough, maybe will do my friends car next)

Be sure to place some tape over the ends when you push the line thru the tunnel, to prevent dirt from getting inside the line.

Nylon 11 is heat resistant, and totally fuel resistant. It is the stuff to use, and since it is not 30 years old, it is very flexible, unlike the orignal, and any metal lines.

McMaster Carr has an online catalong, has the line in different colors (I choose natural Nylon color) and avalibale in metric, and english sizes. check them out, you'll be happy with this product.

I just replaced each of my lines from the tank to above the tin in the engine compartment with a single piece of 5/16 stainless from Summit. I did this with the engine in the car. Getting the lines through the tunnel and up under the tank is very easy. Bending them around the engine compartment with the engine in the car was a pain. If I had it to do over again I'd do the lines in two pieces - one from the firewall forward and the other in the engine compartment.

Could you use some of this "multi fluid" hose I'm seeing now? I was at FLAPS the other day, needing some FI hose for some lines in the engine compartment. The counter guy said he could sell me some "FI" hose for lots-o-bucks per foot, or he had this hydrolic multi fluid line for alot less. Lableing on the hose suggested it was fuel safe, and good for something like 300 psi, certainly more that needed for out FI system. It was black, and seemed a little more flexable, easier to work with than the "official" FI labled hose.

Anyone use this before, and would it be a cost effective material for the in tunnel fuel lines?

I replaced mine with OE type material.
I figured that if it lasted 32 years OE then it will last 32 more with new.

I went aluminum... I think it CAN be done with the engine ing the car if you jack it up enough and don't mind being on your back that long... if I were to do it with the engine in the car, I wouldn't run it the "right" way... I would just run it through the tunnel and make 1, 90 degree, turn then put good, flexible line the last 2-3 feet... why? because those bends would be a BITCH with an engine in the way... that metal line would basically last a lifetime in the tunnel, and the flex line can be swapped as often as needed.

I've heard aluminum can crack, but I dunno why it would...

QUOTE (Cap'n Krusty @ Aug 26 2005, 08:03 PM)

Why? Is yours broken or leaking? Other than the area between the engine and the firewall, I've never seen one fail. (32 years and counting.) The Cap'n

the plastic hose in my Daily driver 74 is nice and pliable....

the hose in the 73 paperweight is brittle and snapped in several places when i was trying to take out the facet pump.....

I ran a 3/8" supply and a 5/16" return line through Babydoll's tunnel last weekend. I used mild steel brake lines, and flare fittings to make the 90 degree bend where the lines enter the engine compartment. Now it's all metal from the fuel pump hose back, and it looks pretty sanitary if I do say so myself. But I could never, ever have done it with the engine in the car.

Is it better to revive an old thread or start a new one?

I have a couple of questions for those of you who replaced the tunnel fuel lines with plastic. Did you reuse the steel ends from the original fuel lines? If so, did you do anything special to ensure a tight seal between the old steel and new plastic? If not, did you do anything special to provide reinforcment for the hose clamp over the plastic line? (does that last question make sense?)

Thanks for any answers, as this should be one of my next projects (to prepare for the return of FI)

The steel ends are barbed, and the only thing that will give or wear away was the old plastic line. Factory did not use any clamps on this connection

If you have the correct inside diameter plastic hose to replace, put it on and that should be the only thing you will need. If you are worried you can do a hose clamp, but I would stay away from the stamp slot ones you get from FLAPS, and use a smooth band one for FI connections.