Brass on aluminum in the fuel line question

[dflarsen77]

I have this new 70 C10, and it came with a Edelbrock 1406. I've always thought Edelbrocks were cool, so I was excited about it, just cleaned & rebuilt it. I've read a bunch on it from this site and elsewhere, and I'm already redoing my fuel system for several reasons, but I'm doing a fuel pressure regulator, which I already have, one of the Summit models. The problem I'm asking about is the fittings.

The fuel pump I'm pretty sure is a 3/8 inverted flare female from the pump toward the carb. I checked out a couple threads where people run a 3/8 brake line that you can buy for $5 at parts stores, with fittings installed, bend it how you need, and ... voila?

So at first it makes sense, it's a couple 3/8 fittings in the plan, but when I start actually getting parts, I learn that the brake line, and in general any inverted flare fitting for 3/8 tubing has 5/8-18 threads, straight. 3/8 npt do not match them, as I have learned npt is not a straight fitting, that's how it seals, etc, and inverted flare threads only need to be straight because they just put pressure on the flare, and it's the flare that seals. I've accepted that, no prob.

The problem I have is how people are connecting the flare fitting to the 3/8 npt port on the fuel pressure regulator, which has a 3/8 npt port. There's an adapter that converts it, 3/8 female inverted flare to 3/8 malenpt, makes the setup I am planning work like a charm. The problem is that adapter is only made out of brass that I can find, and all the pics of people using it show brass adapters. Now as far as I know, playing brass with aluminum is bad. And I'm pretty sure the brake line is steel as is the fitting attached, and steel and brass an aluminum is bad. So you guys that have done this, are you have nasty corrosion?

I could just run fuel hose, but that's just as dangerous. And I could do AN stuff, but that's a bit more than I want to spend right now. But if that's the way, cool. Just looking for input and hopefully a solution. I know people talk about doing their own tube, doing the flares, which I could do, but it still doesn't solve the flare to npt issue.

[special-K]

What aluminum?

[dflarsen77]

The fuel pressure regulator is aluminum.

[Big Kev-O]

Galvanic Corrosion happens because of the different in electrical potential. The amount of difference (and the environment) that determines how fast one metal will corrode.

Aluminum has an anodic index -.9
Brass has an anodic index of about -.4
They are fairly close so galvanic corrosion is very slow.

I have seen and used brass fittings on aluminum parts & lines without any issues. Demon and several others big brands sell brass carb inlet fittings that thread right into aluminum carbs.

[davepl]

I've used brass in fuel systems before, as did the factory (take a look at the Holley dual-feed setup, it includes brass adapters, but for steel line, so it's a little different).

What I can't claim for sure is that I've had the brass directly in contact with the aluminum, but I'm pretty sure I did...

[special-K]

Originally Posted by dflarsen77

The fuel pressure regulator is aluminum.

Gotcha. As mentioned, the brass is better than steel against aluminum. Very slow process. Teflon thread tape will help isolate as well. I have mixed the soft metals in many cases, such as copper/brass/bronze/stainless with no ill effects seen. Basically, steel being so prone to oxidation is the issue. It is the homesick bad boy of metals and want to get back to where it came from asap and looking for any excuse to get there.