fuel hardline quality control

[stuchman1]

Friends,

Another newbie question - we've been working on installing zinc-steel 3/8" hardline for fuel and trying to get clean bends. I'm using the loaner heavy duty bender from Autozone and I can't seem to get the bends as clean as I want, meaning not kinked, despite multiple attempts including doing it all by hand or with one handle in a vice. You may be able to see on the outside of the bend, the center folds in a bit. I tried changing out the tool for another of the same and I get the same result. Also tried the one with just one handle and that's pretty much useless with thicker line like this. Am I being too picky and it's fine, or is this going to restrict fuel flow?

Thinking ahead to possible plan B if this is just insurmountable user error (), what are the group's thoughts on doing flexible steel-PTFE lines for the entire system, other than increased cost? I guess durability, but if those lines are durable enough for the ends of the lines, they should be good enough for the entire line?

Thanks as always!
ST

PXL_20240525_174123286.jpgPXL_20240525_174137987.jpgPXL_20240525_174149526.jpgPXL_20240525_174158727~2.jpgScreenshot 2024-05-25 at 2.05.57 PM.png

[Jeff Kleiner]

Ditch the steel tubing and use NiCopp Nickle/Copper. Bends like butter

Jeff

[stuchman1]

I was going to do that but Earl's 3/8" is discontinued. I have Earl's fittings and I"m trying to follow the advice of sticking with the same brand as much as possible, to ensure compatibility.

Assuming that's not a significant concern, any recs on brands? I see lots sold on Amazon, etc., but not clear which brands are the most reliable go-to's.

Thank you!

[egchewy79]

I ran flex braided SS PTFE lines for the entire length. Fewer junctions to possibly leak and no bending required.

edit: I used Fragola lines, ordered through Mike Forte w/ fittings already installed after I provided him the lengths I needed.
FYI, depending on lines used, the OD is smaller for PTFE SS vs regular rubber braided SS lines. This makes a difference when getting hose separator clamps to attach the lines to the frame. I think Earls has the proper clamps for this.

[edwardb]

I'm personally not a fan of that multi-size style bender. My experience is similar to yours. Plus I've kind of given up to the parts store rental tools. My experience is they're often pretty beat up or worn. Maybe not everyone's experience. But has been mine. I did rigid SS fuel and brake lines on several builds and found these Ridgid benders worked great. Would easily bend steel. They're not cheap. But much more expensive ones out there. The smaller bender is from Inline Tube for small radius bends on brake lines. Can't argue with using NiCopp which I haven't done, or SS flex which I have done.

[JohnK]

I was going to post the same thing as Edwardb. Most of the problem is those multi-size benders. It's a bit of an investment, but if you get a dedicated 3/16" bender for brake lines and a 3/8" bender for fuel lines you'll have far superior results with any type of tubing, including stainless steel.

[Mike.Bray]

I second what Edward said, you need a good quality bender for steel or stainless steel hard lines. This might help. https://thefactoryfiveforum.com/show...AN-Brake-Lines

Ridgid doesn't make their fine line of benders anymore but you can find them on eBay.

Or as Jeff said, use NiCopp hard line, bends like butter and is more than adequate for fuel lines.

For the relatively low pressure of fuel lines you can use AN - compression fittings like these. They are easy to install and work great.

[stuchman1]

Super helpful. Thank you all!

[Lidodrip]

I went the NiCopp route and would recommend it. Easy to bend without buying expensive tools, relatively inexpensive, easy to straighten, and durable (several European manufacturers use NiCopp for their cars). I used tubing from both Amazon and my local auto parts store - no issue with fitting compatibility or quality.



James

[Railroad]

The steel tubing in your pictures looks unusual to me. It looks like EMT, electrical metal tubing. I have never seen 3/8 EMT, but there is a lot I have not seen.
If so, this is not designed for gas lines. It can be bent with an emt tubing bender, but the curves will have a much larger radius.

[CraigS]

Since mine was a carb engine runnng <7# fuel pressure, I used hose clamps and rubber fuel hose at the ends of the NiCopp. Tank pickup, hose w/ clamps to fuel filter, to hose w/ clamps to NiCopp. I ran a mechanical pump so coming from it to the carb I did run SS braided. It was easy to do w/ adapter pipe thread to AN at the pump and AN to AN at the carb.

[stuchman1]

The steel tubing in your pictures looks unusual to me. It looks like EMT, electrical metal tubing. I have never seen 3/8 EMT, but there is a lot I have not seen.
If so, this is not designed for gas lines. It can be bent with an emt tubing bender, but the curves will have a much larger radius.

Just to respond to this, it's not EMT. It's Earl's zinc steel hardline. Thanks, ST

[steno]

Pinching on benders quite often is from the tubing creeping/moving in the bender as you bend it. A good bender will make it much easier

[Dave M]

Try putting some oil on the tubing. The caving in on the outside of the bend is usually caused by the moveable shoe dragging on the tube instead of sliding easily. Did a lot of custom exhaust work back in another life and we’d have the same problem if the bending machine dies got dry.

[toadster]

I like the NiCopp too

[Avalanche325]

You are letting the tube come away from the bender. Yes, there are easier to use tools and easier to bend lines, but you should be able to get clean bends with that tool.

Putting it in a vice is likely not helping you control it.

[Theshandman]

I ran flex braided SS PTFE lines for the entire length. Fewer junctions to possibly leak and no bending required.

Same here. I used Tech AFX 'BlackWrap' lines. Super easy to custom fit and install. No hard bends and not a drop of fuel nor the odor of gas.

[CDXXVII]

I ran stainless steel hard lines for everything and used ptfe stainless braided for final fuel line connections. Pretty much overkill but I love the look. BTW, I had no issues with leaks but you do need to be very careful when you prep the line before flairing.