AN Flares For Fuel Lines Questions

[Daddy O]

Hello All,

I have the Eastwood turret flaring tool with the 45 as well as the optional 37 degree dies. Any reason not to flare for AN -6 on the 3/8" nicopp feed and return hard lines? Only flaring experience I have up to this point was the 45 degree 3/16 brake lines which worked out great. Line pressure will be EFI levels. Are aluminum AN nuts and sleeves sufficient?

Thanks for any insight!

[NAZ]

I've never used nicopp tubing; my AN tubing experience is with alum, steel, & S.S. If you want to try making AN hard fuel lines then make sure you get the correct adapters and have at it. The fittings are rated for much higher than common spark ignition EFI pressures. So if not plumbing high pressure direct injection systems you should be OK.

https://www.summitracing.com/parts/sum-2200075

[frankeeski]

I'd stay away from the compression connectors if you can. I prefer the stainless fittings I get at my local hose shop but the aluminum ones from the speed shops work just fine. And just like when flaring brake lines, make sure to slide your tube nut and tube sleeve on before you flare the end. To be clear, you'll be using a male union, tube nut and tube sleeve to attach to the fuel hardline. Most important, make sure to lube the fittings when assembling. You'll get the fitting tighter and leak free the first time.

[Rockman]

The Eastwood flaring tool is great, it makes perfect flares. When I do my 37 degree flares for AN-6, I do it as a single flare. I do OP 0, then for OP 1, I loosen the clamp and gently let the tube be pushed into the die, clamp tight and then do OP 2 to finish it off. I used Ni Copp for AN-6 fuel feed and return lines, very easy to bend. I used aluminum sleeves, nuts and unions with no issues. At the terminus of the hard lines I had custom length hoses made by Aircraft Specialty http://www.aircraftspecialty.com/ They are very helpful and make very nice flexible hoses that will fit perfectly. To make sure the AN fittings are properly tightened, I used the "counting flats" method. See https://www.pegasusautoracing.com/document.asp?DocID=TECH00157

[Scneal]

I used Nicopp and Earl's AN tube nuts and tube sleaves against a 37 degree flare. Both Stainless and Aluminium nuts will work great for you. Mine is done in Black aluminum. You should have no issues flaring the nicopp as it's easier to work with than steel. Plus I used the Eastwood straightener to create a really straight line down the frame rails. #30539 $84.79 - back in stock later this week. I did two single pieces out of a 25' roll for feed and return lines. Once in the engine compartment, I went to Earls braided hose and fitting to complete the connection. The back end used Earls vapor guard. Not the cheapest but it sure looks beautiful under the hood.

[Daddy O]

Thanks for all the responses. What is the preferred lube? Assuming this goes on threads and mating surfaces.

[cv2065]

Breeze can get you hooked up with all of the fittings that you need. Just give Mark a call and he'll set you up.

[Hoooper]

Thanks for all the responses. What is the preferred lube? Assuming this goes on threads and mating surfaces.

On fuel line pretty much anything is fine as long as its not incompatible with the fitting material. Very little is actually in the fluid stream since it goes on the mating surface and the threads. You will see people basically just use whatever they have around, WD-40, anti-seize, engine assembly lube, oil, moly grease, etc. I just used leftover ARP fastener lube on all my oil and fuel fittings. Using lube on AN fittings makes a big difference in how nicely the fittings thread together and at least in my experience more consistent sealing up on first assembly.

[mikeinatlanta]

Question about the Eastwood tool. Does it make the flare purely by pushing the tube over the die or does the die make a circular motion that also finishes the sealing face? Makes a huge difference on AN flares. If it just pushes the tube over the die then you should really perform a follow-up action to provide a proper finish on the sealing surface. This is especially important when using the fake seamless places like Summit sells.

EDIT: Photos attached. One shows a close up of the flare sealing area with a flaring tool the pushes the tube over the die and one that shows the sealing area on a flaring tool that rolls the flare. The one with the rough surface needs a post flaring refinish of the sealing surface or it may leak.
154782154783

[PNWTim]

I have used this tool for both and it works great. I also have the Rigid flaring tool for the 37 degree and no problems there either. You can buy any aluminum AN fitting in the world from Summit in almost every color. This is more than adequate for the 50 to 60 psi most EFI setups are running at these days.

[frankeeski]

What is the preferred lube? Assuming this goes on threads and mating surfaces.

The rule is generally what ever fluid is going to be transferred through the line is what you use for lubrication. So:

Transmission lines-use transmission fluid
Brake lines-use brake fluid
Oil lines-use motor oil
and so on

There are some exceptions. For most fuel lines use a light motor oil since gasoline, E85 and Alcohol act as a solvent and have little to no lubricity. Diesel fuel is a bit different. Engine coolant is tricky. The glycol in coolant will work, but if you're running straight water for racing you may want to, again, use a light motor oil.

I have 5W-30 in an old Lucas bottle that has a spout on the end. A few drops on the tip of your finger is enough to smear on the end of the fitting and the threads.

Mike brings up a good point above about the type of flaring tool. I haven't used the NiCop tubing so I don't know just how soft it is. But for sure if you were using, say steel or stainless steel, the twisting action of a screw type flare tool helps to anneal the surface and make the inside of the flare more pliable so it seals up better. My shop is just North of you and I have an awesome Ridgid Tools flare tool I use for AN fittings. I don't like loaning out tools but it might be worth a trip up here to see how it works and who knows?

[mikeinatlanta]

The Rigid flaring tool is the best there is until you get to seriously high dollar tools, and it's better than most of them too. It leaves a high gloss polished finish on the sealing surface of NiCop tubing.