Fuel line solutions...

[Bill K.]

Here's how I replaced my fuel line (for those who want details...)

Background:
Wanted to upgrade fuel line size for new motor (2270 T4) and electric fuel pump (Carter rotary). Performing body off restoration. No plans for fuel injection. Have seen other installations on the web and was concerned about the complexity of cutting into the tunnel to secure the fuel line. Wanted to keep fuel line in the tunnel for safety reasons. Did not want to have rattles from a loose line in the tunnel. Decided to place fuel line inside plastic sheath next to original line and use original inlet/outlet holes with modified stock grommets. Used McMaster Carr parts for cost and availability. Used Germain braided rubber fuel hoses for cost and reliability.

Materials from www.mcmaster.com:
* 5176K25 -- Roll-Formed Carbon Steel Coiled Tubing 3/8" OD, .319" ID, .028" Wall, 25' Coil -- $20
* 5182K266 -- 316 SS Yor-Lok Compression Tube Fitting Female Straight Adapter For 3/8" Tube OD, 1/4" NPT -- qty 1 -- "Outlet adapter" -- $10
* 5182K156 -- 316 SS Yor-Lok Compression Tube Fitting 90 Deg Elbow, Tube X Male For 3/8" Tube OD, 1/4" NPT -- "Inlet adapter" -- $15
* 5346K16 -- Brass Hose Fitting Barb X Male Pipe For 5/16" Hose ID, 1/4" Pipe -- 10 pack -- $5
* 5011T141 -- 316 SS Worm-Drive Hose & Tube Clamp 7/32" To 5/8" Clamp ID Range, 5/16" Band Width -- 10 pack -- $5

From Home Depot:
* 1/2" thin wall black PVC tubing for sprinklers -- $?
* 1/4" NPT female coupler -- connects inlet adapter to barb -- $1

From VW parts store:
Fuel line grommets -- qty 2 -- $5
7mm German braided fuel line -- qty 3 meters -- $20

Total parts = $80

Procedure:
1. Body off restoration -- beam on, trans in, pedal cluster out, shifter out, e-brake out
2. Remove the front and rear fuel line grommets and discard if old.
4. Cut original fuel line from rear seat access hole using dykes. Leave the line in for now you will use it to guide the new line through the frame horn. Note how fuel line goes under the torsion housing.
3. Pull the front fuel line up as far as you can outside the tunnel then cut off the curved part. Push remainder of line back down into tunnel through pedal cluster hole.
4. Straighten the new fuel line coil by bending with your hands. Leave about half the coil coiled and use as a handle to push/twist with. Leave about 4-6" of the end bent a little to route under the torsion tube and up to the outlet hole in the frame horn.
5. Push the new fuel line into the PVC tubing for the entire length of the chassis.
6. Push the fuel line with PVC tube loaded into the tunnel from the front access hole. Route it to the passengers side of the original line under the front crossmember. Feed it back, twisting as needed, to the rear access hole.
7. Use the cut peice of original rear fuel line as guide. Thread the new line over the cut end of the old line. Guide it under the torsion tube from the rear access hole. Don't jam the PVC tube past the torsion tube, just advance the fuel line until it is visible in the fuel line outlet hole of the frame horn. Have a helper push the line while you guide the end of the new line through the outlet hole. Crush the end oval with a screw driver if needed to clear the opening. Push the line through as far as possible until it binds, then bend it up a little to releave the binding then push some more. Repeat the bend-push routine until 1-2 feet of line are exposed out the rear.
8. At the front, measure how far the end of the PVC tube is from the pedal cluster hole. This is how much you need to cut off. Pull the PVC tube out (leaving the fuel line in) until the measured amount is exposed. Cut the PVC tube off the fuel line with a circular cut. Now push the PVC tube back into position using the cut piece. The ends of the PVC tube should be at the torsion tube and at the pedal cluster hole in the tunnel.
9. Cut the coil off the fuel line about 6" from the frame head. Then with a tube bender, bend into a 90 degree by 2" radius curve with about 1" of straight on the end. Bend it up so it will go through the inlet hole in the frame head.
10. From the rear, pull the line inside the frame head and align the bent end with the outlet hole. Use as big a phillips screwdriver that will fit inside the line to guide the line through the hole. From the pedal cluster hole, bend the line up using a bar. Push from the rear, bend the line using the screwdriver (being carefull not to kink the line), then push some more, etc. until the line is exposed by an inch or so. From the pedal cluster hole, carefully bend the line using bars so it is not bound on the bottom edge of the front tunnel crossmember.
11. Trim the ends of the line and grind square and debur. Blow out inside of tube to remove debris.
12. Modify stock fuel line grommets by inserting in a socket and enlarging the ID with a rotary file. Install grommets to secure the ends of the line to the frame.
13. Attach the compression fittings, barbs, fuel hoses, and hose clamps.

Installation took me about an hour. I was surprised how easy it was compared to other procedures I've seen which involve cutting the tunnel and welding in tabs to hold down the line. Securing the line along the tunnel seems overkill. Having the body off made installation a lot easier. I like keeping the fuel line in the tunnel and away from potential crushing, leaking, and sparking in the ****pit (boom).

The 3/8 "bundyweld" tubing I used is flexible enough to route through the tunnel, but stiff enough to stay in place without clamping down. It's copper plated, soft anneal carbon steel tubing with an aluminum based paint on the outside. The PVC sheath should prevent rattles and act as a full length grommet. The Yok-lok compression fittings have a compression seals that crush the steel tube to form a tight seal even if the tubing is not round from bending etc. Seems like these fittings would work on aluminum tubes too. Similar sized aluminum would be flexible enough for routing, but stainless may be too stiff for routing and compression fittings. Stainless could be flared nice with the right tools, but tricky compared to the Yok-lok. I don't know FI or your engine, but 1/2" line might be overkill and harder to work with. The 3/8 OD by .319" ID tubing with 5/16 barbs (.25" ID) and 7 mm (.28") ID german fuel hose is a non restrictive flow path for a Carter rotary fuel pump to dual carbs feeding 2270 cc up to 150 hp. To ensure full flow to the pump, I'm tapping the tank outlet bung to 1/4" NPT and connecting a 1/4 NPT to 5/16" barb for the 7 mm line to the filter.

This technique should work for FI. You could keep, replace, or upsize the original line for return and place the new feed line through new inlet/outlet holes.

Pictures show finished job.

Full flow for power,
Bill

[MattKab]

Awesome

Matt

[boygenius]

WOW... Are your fingers sore yet from typing. Thanks for the advice... :agree: :agree:

[boygenius]

So I decided on 3/8" feed line and 1/4" return line. SO that would mean that I need 6-an and 4-an tube nuts so the fuel lines can be attached to the rest of the fuel system. Do I need the tube sleeves also if I'm using stainless steel fuel line.?? Can I use aluminum tube nuts with steel lines since summit was out of stock on the steel tube nuts I needed.??

[boygenius]

Ok so I bought some 3/8" and 1/4" stainless steel fuel line for my car and is it ever a pain in the but to bend. Since I will have 2 fuel lines I don't think they will both fit through the top of the tunnel like the factory line did. I was thinking of bringing them out the right side of the frame head opposite the M/C. Maybe just drilling an extra hole in the frame head next to the original hole. Can somebody post some pics of the the area under the fuel tank on the right side of the car (standard). My body isn't on the chassis right now and I don't wan't to run into any problems when the body goes back on.

[nbturbo]

If you look at what the new cars are coming out with,just try to copy what they use.Here in Australia they use 10mm supply and 8mm return(3/8 and 5/16) and use plain/ordinary steel tubing.As I said,just use the same pipe that used for brake lines because it is steel with a coating of some sort which is the same as OE fuel lines.You will find it a lot easier to bend with simple tools and get it into your pan.I have run the 8mm return alongside of the original 5mm fuel pipe and it goes into and exits the pan just near the 5mm one.The 10mm one was easy to get out the back thru the rear yoke(a couple of inches away from the other 2 and all in line ) but was a bastard to try and get out the front-so drilled a hole in the side of the front frame opposite the brake M/Cyl and put a 90 bend in the pipe and pulled it thru.Have made a small aluminium bracket and used one of those insulated clamps just pictured here. just to clarify-I put the tube thru the pan and had spare hanging out each end.I put the bend in the pipe at the front(coming out the inspection hole for the removal of the shift rod) and flared the end to hold hose then slowly pulled it towards the back until the bend came near the hole in the frame head-I had it bent so that there was some tension against the inside of the pan-when I could see it thru the hole I forced it out the hole by pulling and levering from the inside-it took a couple of goes but ended up OK. Fitted the bracket and clamp.At the back you have to manipulate this a bit at the same time to keep it with a nice flowing bend where it comes out the pan.when all was OK just cable tied them all together thru the gearshift coupling hole as far forward as possible,this will test you hands.Last job just cut the excess pipe off at the rear and put a flare on it.I just use a double flare kit but only do about half of the first part of the process.Gives a lovey shoulder to seal hose.

[boygenius]

Can anybody recommend a good tube flaring kit. I already broke part of the one I bought and all it does is bend the end over instead of flaring it. For refferance I am running 3/8" and 1/4" stainless steel fuel lines. Thanks...