EFI Fuel lines

[toddz69]

The problem I keep coming up against with hard lines is making that transition from hard to whatever, in my case AN hoses (I use PTFE braided and cut it with a simple cutter-no problem there). But getting an N fitting on a hard line is the issue. With aluminum tube, there are compression fits. But the problem is those are not rated for EFI pressures, So you need to use steel. But there are no compression fittings for steel with EFI pressure rating that I know of, just weld on stuff. Please tell me I am wrong and make my day!

I believe these Fragola fittings would work for the EFI pressures?

https://www.summitracing.com/parts/...EIgL0Lh67qYW83kZteh3sO6kn05l1IwRoCAxEQAvD_BwE

Todd Z.

 

[ntsqd]

This is the flaring tool that I now have: https://www.aircraft-tool.com/detail?id=212FB It isn't inexpensive (SWMBO spoils me at Xmas!), but it makes a perfect flare every time in every metal that I've tried it on (AL, SS, Carbon Steel, & CuNi)

The problem of the tube sleeve not fitting over the AL tubing is due to the tubing not being made to a tight tolerance and it is slightly too large. I use one of the old school 45° flaring tool clamping bars and clamp the aluminum tubing several times from the end down to as far as I need the tube sleeve to go for clearance in the above flaring tool. That shrinks the AL tube's OD down to a diameter that works. AL is the only tubing that I've had to do this with.

 

[bmc69]

I never liked the idea of hose running the entire length of the frame. I use Summit's coil of aluminum hardline to run from front to back and flare it to AN. Then a short section of hose to the pump and rail. The aluminum hardline is very easy to work with.

I use the CuNi tubing for that..and brake lines too. The environment here rots out the aluminum lines about as fast as steel ones.

 

[ntsqd]

That's a topic that I've been curious about, how does the CuNi tubing hold up in a marine environment. Sounds like fairly well. Brit Sports Cars have been using it for decades and once the initial verdigris occurs, it doesn't seem to corrode further.

 

[bmc69]

That's a topic that I've been curious about, how does the CuNi tubing hold up in a marine environment. Sounds like fairly well. Brit Sports Cars have been using it for decades and once the initial verdigris occurs, it doesn't seem to corrode further.

It's very widely used in marine environment. We use the heck out of it for carrying saltwater around the ship...for everything from HVAC and refrigeration chiller coolers to the oil coolers on hydraulics, main engines, transmissions, fire mains, etc

 

[ntsqd]

Thank you!

 

[bmc69]

Thank you!

And...CuNi is a very generic term. The actual alloy ratio matters... https://www.sunflexmetal.net/cu-ni-70-30-vs-cu-ni-90-10-material-guide/

 

[EFI Guy]

I use the CuNi tubing for that..and brake lines too. The environment here rots out the aluminum lines about as fast as steel ones.

I've been curious about the CuNi myself, I have never tried to work with it personally. I may have to give it a shot on an upcoming project.
I've done a bunch of work with stainless and I don't mind bending it, but it's difficult to flare properly for any sort of push-lock fitting, even with a hydraulic flaring tool.

 

[bmc69]

I've been curious about the CuNi myself, I have never tried to work with it personally. I may have to give it a shot on an upcoming project.
I've done a bunch of work with stainless and I don't mind bending it, but it's difficult to flare properly for any sort of push-lock fitting, even with a hydraulic flaring tool.

That's the beauty of CuNi tubing. It's almost as easy to flare as copper (especially the 90-10 CuNi) but very corrosion resistant...as good as Chinese stainless and almost as good as certified 316-series stainless tubing.

I use an Eastwood multi-flare tool setup. A bit expensive...but perfect flares every time.

 

[EFI Guy]

I use an Eastwood multi-flare tool setup. A bit expensive...but perfect flares every time.

Are you using their turret style tool? I'm using the hydraulic version and it works great...But with stainless it likes to slip in the die blocks when trying something like a push-lock.

 

[ntsqd]

I'm using the Parker 37° flaring tool. I've only flared -3 so far, but it works so easy that it's been on my mind to use this type of tubing for the Wagon's fuel system. A simple search found for me The Stop Shop who offers the tubing in 3/8", can buy it from them off amazon. They also offer the armor coil in SS for the 3/8" tubing, which is tempting. I reused the plated steel guard coil on Snowball's brake plumbing because I didn't know that it was available.

 

[Broncobowsher]

That's the beauty of CuNi tubing. It's almost as easy to flare as copper (especially the 90-10 CuNi) but very corrosion resistant...as good as Chinese stainless and almost as good as certified 316-series stainless tubing.

I use an Eastwood multi-flare tool setup. A bit expensive...but perfect flares every time.

How is that high copper allow at holding pressure. I have heard several stories about someone having poor brakes because they plumbed copper in for brake lines (yea, I know this is an EFI thread, but we are diverging into a hard line allow side note) and the copper flexed under brake pressure. I could see how adding nickle to the copper will stiffen it up. This is also the first time I heard there were different alloys of copper nickle line available. Always just heard it referenced to as copper nickle, much like calling something stainless steel. But there are a ton of stainless steel alloys. So I guess there would be multiple alloys.

 

[ntsqd]

I don't have much length of the CuNi tubing in Snowball's rear brake system (just the width of a full size D60), but pedal feel is outstanding!

I have to wonder if whomever used the right tubing, maybe they grabbed pure copper?

 

[Jdgephar]

The problem I keep coming up against with hard lines is making that transition from hard to whatever, in my case AN hoses (I use PTFE braided and cut it with a simple cutter-no problem there). But getting an N fitting on a hard line is the issue. With aluminum tube, there are compression fits. But the problem is those are not rated for EFI pressures, So you need to use steel. But there are no compression fittings for steel with EFI pressure rating that I know of, just weld on stuff. Please tell me I am wrong and make my day!

I used these.

https://www.amazon.com/dp/B0BN5SVK35/?tag=classicbroncos-20

Rated to 1500 psi (claimed)

Sent from my SM-S916U using Tapatalk

 

[bmc69]

Are you using their turret style tool? I'm using the hydraulic version and it works great...But with stainless it likes to slip in the die blocks when trying something like a push-lock.

yes.

 

[bmc69]

How is that high copper allow at holding pressure. I have heard several stories about someone having poor brakes because they plumbed copper in for brake lines (yea, I know this is an EFI thread, but we are diverging into a hard line allow side note) and the copper flexed under brake pressure. I could see how adding nickle to the copper will stiffen it up. This is also the first time I heard there were different alloys of copper nickle line available. Always just heard it referenced to as copper nickle, much like calling something stainless steel. But there are a ton of stainless steel alloys. So I guess there would be multiple alloys.

I've been using the eBay cheap CuNi tubing for years, mostly on brake lines.

 

[ntsqd]

I used these.

https://www.amazon.com/dp/B0BN5SVK35/?tag=classicbroncos-20

Rated to 1500 psi (claimed)

Sent from my SM-S916U using Tapatalk

What I don't like about that solution is that it is hard to secure the end of the tubing. The way that I see it is that the fitting and the hose end screwed to it are a weight on the end of the tubing, and any tubing between it and a clamp is the length of the pendulum, with any vibration making it wobble aback and forth - which hastens the eventual fatigue failure of the tubing.

The flip side to my solution of using a bulkhead union thru a tab or something structural on both ends is that thermal expansion/contraction of the tubing has nowhere to go. I make a point of any tubing in a plumbing system like this having at least one bend in it so that the expansion does have somewhere to go.

 

[Shimmy]

my entire brakeline system (minus the SS lines from the frame down to the axles) is copper nickel. easy to flare, bend, no issues with pressure. I'm running hydroboost.

 

[MarsChariot]

Thank you Jdgephar, that is all I wanted. I don't know what all this talk about CuNi tubing and such is, but I understand that description. I just want to but an AN fitting on steel hard lines and have it be sufficient for EFI pressures.

​

 

[ntsqd]

That's easy, buy a quality 37° flare tool (I recommend the Parker, but others will work too), and buy the correct size of AN tube nuts and tube sleeves. Slide on the nut and then the sleeve, then flare the end. These are single flares, so they're fairly easy to form. That gives you AN female threads and sealing surface. If you need male threads and sealing surface then either a union or a bulkhead union tightened into the tube nut will yield that.