Fuel Line Springs

Not for fuel lines, instead for flexible hose that tended to fold or collapse inside a mold for a concrete part. Wire cable of the right diameter worked better than springs for that application. I can imagine cable getting stuck inside a bending fuel line ~ jiw

How about using steel-braided fuel line? It's abrasive if it vibrates and rubs on anything but it shouldn't collapse on you.

Found a stainless barb elbow that will just do the trick. If I hadn't guess I could make one. No more bad bend in the hose.

In messing with this marine engine I've noted the fuel line from the pump to the first carburetor (feeding all three from there) is nearly impossible to route without kinking or flattening the line and restricting fuel flow. It may not be an issue, but I'd like to eliminate it as a possible cause of problems. I think the original was likely a preformed hose with an expensive OEM part number.

I debated maybe digging out my double flaring tool, and bending a steel fuel line to go in its place with just a short run of rubber line at each end, but I don't think there is enough room to bend a steel fuel line to fit without kinking. My bending die that size has a radius to large for the job, so I would need to make one just to try. I've used v-belt sheaves in the past as a make shift bending die, but I don't have anything small enough for this. No matter what you use if you go for to small of a radius it will either kink or split.

Then I ran across fuel line springs. Have any of you guys ever used a fuel line spring for an application like this to keep the line round and open? Either internal or external?

Bob La Londe CNC Molds N Stuff

------- I looked at the springs but brake line bending pliers similar to the OEMTOOLS 25440 could copy the numerous bends in the front-to-rear brake line I was replacing, are more controllable and don't jam.

You might try NiCopp tubing. It's also nicer than steel for making double lap flares. You can make custom diameter bending dies on a milling machine by rotating the blank against an end mill.

I've used it a couple times. Was amazed by how easy it bent by hand (strong fingers help) and not kink. Even had to redo a couple spots several times...

It's not that expensive and can be found at most auto part stores around here.

How soft is it? Can I slide a rubber hose over a double flare (not finished) and seal with a hose clamp or will the tube distort and leak?

I can't really change the fittings on the carbs as near as I can tell. They appear to have been cast in place.

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I think it would hold up to a hose clamp. Just stop at an auto parts store like NAPA... That's where I've picked it up locally. You can look it over then and make up your own mind if it might work or not...

How soft is it? Can I slide a rubber hose over a double flare (not finished) and seal with a hose clamp or will the tube distort and leak?

I can't really change the fittings on the carbs as near as I can tell. They appear to have been cast in place.

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NiCopp is noticeably but not greatly easier to bend than the same size steel brake line. It's considerably stiffer than copper, and suited to brake line pressure which copper isn't. As Leon mentioned bending it (3/16") does stress the fingers, I used the pliers-like tool for better control.

What is break line pressure?

I did some research a while back on pressure rating for soft copper tube in regards to R410A refrigeration tubing and found that the appropriate size tube for liquid supply and return gas were adequate. Even in full size (5 ton) systems. In mini splits its common and often is terminated with single flair fittings. (different angle than automotive)

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Most of the docs for the specs are behind paywalls...

Found this at O'Reilly Auto:

== Tube Outside Diameter (in): 1/4 Maximum Working Pressure (psi): 2900 psi ==

What is break line pressure?

I did some research a while back on pressure rating for soft copper tube in regards to R410A refrigeration tubing and found that the appropriate size tube for liquid supply and return gas were adequate. Even in full size (5 ton) systems. In mini splits its common and often is terminated with single flair fittings. (different angle than automotive)

---------------- I was asked to make sample brazed joints at work to see if I could handle refrigeration. They didn't complain about my work but never asked me to do it again.

"Typical brake line pressures during a stop range from less than 800psi under "normal" conditions, to as much as 2000psi in a maximum effort."

"Here are the burst pressures based on the line size:

3/16" is 11,909 PSI 1/4" is 8,932 PSI 5/16" is 7,146 PSI 3/8" is 5,955 PSI

The materials are 90% copper and 10% nickel."

I burst an OEM brake line at a hidden rust spot while panic-stopping the car at the top of ramps. If something's gonna fail there's no better place than on ramps in my driveway. The exposed lines had been sprayed with LPS-3 and still had all the green paint on them.

Second best was the truck losing a brake line at a gas station an easy 1/2 mile from home, after driving back from Maine. It was also in a nook that sprayed LPS-3 or washing underneath didn't reach. I've also come home via AAA.

Since then I position the ramps against the tires, chocks against the other tires, measure how far the wheel centers should move and shift the chocks out that far, to positively stop the car atop the ramps.

Tube Outside Diameter (in): 1/4 Maximum Working Pressure (psi): 2900 psi Leon Fisk Grand Rapids MI

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A 3:1 safety factor sounds reasonable, it's the same as for Grade G43 chain. Transport chain is 4:1.

I have copper brake lines on my frogeye (US bugeye) Sprite here in the UK and all quite legal as the wall thickness is suited to the pressure, I didn't make them they were a commercially made kit to suit my car by Automec IIRC and they also do Kunifer (copper nickel) sets also. The issue I've seen mentioned with the US is that HVAC tubing is available in the same size but with a thinner wall and not suitable for brake system usage due to the lower maximum pressure they can take.