Making steel fuel lines. Have questions.

[jtinpdx]

Hi All,
I think I'm ready to tackle getting rid of my rubber fuel line from the pump to the carb and adding a fuel pressure regulator for the Edelbrock carb. I have the flare nut tools and have learned how to make the flares and bend the tubing. But I'd like to ask some questions before tearing things apart.

The stainless steel section coming from the fuel pump that there already, is that stock? It looks like 3/8ths. Should I expect that it's externally threaded and would mate to a female flare nut? Is it NPT? Are flare nuts generally NPT if they're not AN?

At the carb, what is that fitting? Does it need to be replaced? If so, with what? If not, what flare nut goes on that end?

Lastly, I was going to use this regulator. http://www.summitracing.com/parts/edl-8190/overview/
It calls for NPT fittings. I have flare nut fittings from Napa. Are those NPT or should I go back and confirm I have the right ones?

Thanks,
Jeff

[ray_mcavoy]

Originally Posted by jtinpdx

The stainless steel section coming from the fuel pump that there already, is that stock? It looks like 3/8ths.

Yes, that is probably what's left of the stock pump-to-carb fuel line. They were originally steel (not stainless though). Both 5/16" and 3/8" were used depending on the application. If in doubt, you can use an open end wrench slipped over the line to check the size.

Originally Posted by jtinpdx

Should I expect that it's externally threaded and would mate to a female flare nut? Is it NPT? Are flare nuts generally NPT if they're not AN?

The stock fuel line fittings were typically SAE inverted flare. Same as used on stock brake lines only with larger tubing sizes.

The SAE flares are double flares at a 45 degree angle and are not compatible with the 37 degree AN flare. And the threads are typically standard sizes (like fine thread bolts). If I remember correctly, the 3/8" lines use a flare nut with 5/8"-18 threads.

The fuel pump outlet might have a built-in inverted flare seat. Or it might have NPT threads with an NPT-to-inverted flare connector fitting between the pump & line.

Originally Posted by jtinpdx

At the carb, what is that fitting? Does it need to be replaced? If so, with what? If not, what flare nut goes on that end?

It's hard to tell, but I think the fitting currently installed in your carb just has a hose barb. Probably something like this:


So yes, you will have to replace it in order to connect up a hard line. Something like this (Edelbrock # 350-8090) should work if you'll be using 3/8" line with an SAE inverted flare:

Originally Posted by jtinpdx

Lastly, I was going to use this regulator. http://www.summitracing.com/parts/edl-8190/overview/
It calls for NPT fittings. I have flare nut fittings from Napa. Are those NPT or should I go back and confirm I have the right ones?

You'll need some adapter fittings to go from NPT to the flare nuts.

[70STOVEBOLT]

AN fittings should be 45 degree. JIC is 37 degree and they only come in steel, most AN fittings are aluminum. All brass flare fittings are 45 degree. NPT is pipe thread.

[jlsanborn]

AN fittings are 37 degrees, like the JIC. SAE is 45 degree. That is in regard to the tube end of the fitting. The carb is likely a parallel straight thread (like standard fasteners) and uses a gasket like the previous poster illustrated. Fuel pump could be a variety of things but again like the previous poster mentioned you can get a fuel pump with "built in" SAE 45 degree flare.

[jtinpdx]

Thanks for the help, guys. I'll give it a go and take some pics if I succeed.

-Jeff

[geezer#99]

You don't want that regulator. Rated too high. Hard to set it at the lower range.
You need one that max's out at the max pressure an eddy carb likes.
Like this one that max's at 5.5 psi.
http://www.summitracing.com/int/part...2518/overview/

And here an easier way to hook up your line. Has a fitting on it for a gauge too.
http://www.summitracing.com/int/parts/edl-8126

[basketcase]

I've never messed with AN fittings but here is my engine. I used 3/8 line off the Edelbrock pump. It was NPT on the outlet. I used standard flare fittings at the fuel filter, regulator and the Holley carb. Holley low pressure regulator and Summit oil filled pressure gauge.

Tom

[El Dorado Jim]

Originally Posted by geezer#99

You don't want that regulator. Rated too high. Hard to set it at the lower range.
You need one that max's out at the max pressure an eddy carb likes.
Like this one that max's at 5.5 psi.
http://www.summitracing.com/int/part...2518/overview/

And here an easier way to hook up your line. Has a fitting on it for a gauge too.
http://www.summitracing.com/int/parts/edl-8126

you don't want to buy a regulator that's max output is the pressure you want to be, you want one where the mid range is where you want the regulated pressure to be...http://www.summitracing.com/parts/edl-8190/overview/ at least with this one you aren't at the minimum or maximum, would be better than the one that maxes out at 5.5 #

[70STOVEBOLT]

Originally Posted by geezer#99

And here an easier way to hook up your line. Has a fitting on it for a gauge too.
http://www.summitracing.com/int/parts/edl-8126

I think he wants to get away from rubber fuel hose. That fuel line is set up for rubber hose.

[jtinpdx]

Originally Posted by 70STOVEBOLT

I think he wants to get away from rubber fuel hose. That fuel line is set up for rubber hose.

That's true. But I also wanted to install a regulator and gauge. So I compromised. I used the Edelbrock carb fitting with the hose barb and gauge. I used rubber lines to a filter and then to the regulator via NPT to hose barb adapter. I plugged one of the outlets from the regulator. And I used a double flare to NPT adapter for the inlet on the regulator. I made a simple metal bracket to provide support to the steel fuel line coming from the pump to the regulator. Not as pretty of a set up as some I've seen, but I think it accomplished what I was looking to do.

Out of the box, the pressure is 5 psi. The truck idles so much lower and is running so much smoother!!! So I put that up to 5.5 psi? What's ideal for the Edelbrock 1406?

Thanks for all of the help, guys. This site is awesome.

-Jeff

[jlsanborn]

Edelbrock says don't exceed 6.5 psi. Have you checked your float height?

[racerop]

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[jtinpdx]

Originally Posted by jlsanborn

Edelbrock says don't exceed 6.5 psi. Have you checked your float height?

I haven't checked the float height. I'm not familiar with how to do that. What should I look for?

[jlsanborn]

It works just like the float in your toilet tank and is adjustable to set the liquid level. It requires partial disassembly of your carburetor. The service manual is available online. It's not terribly difficult. The fuel level has an effect on metering and should be set correctly first thing.

[bollybib]

Check my Project thread Posts 262 thru 267. It's been 3 1/2 years since I piped it and I haven't had a problem since. If you haven't done so already, invest in a high quality flaring tool and tubing bender, it makes a big difference.