-AN Fuel tank fittings Options

[GrayMatter]

I did a quick search and came up empty. Has anyone tried these? I’m wondering if they will fit our fuel tanks.

http://www.dansperformanceparts.com/sand/s...ing-to-6an.html

[Mark Henry]

I'd have to check but I think the VW bug fitting is smaller than the 914 tank outlet.

[McMark]

I did a little looking around. The tank fitting is M18x1.0 and the VW stuff appears to be the same -- although my research was hardly exhaustive on the VW side. There's a lot of year variations, so some could be different thread.

But I think those are the right ones.

Use Loctite 565 to seal the threads, and let it cure for at least 24h before allowing fuel to come in contact. Don't use any type of rubber oring or washer.

[Mark Henry]

The one issue I have, even if it fits, is the stock fitting has a sock screen and a tube riser that this would eliminate.
The riser stops rust, water (from moisture) and crap from entering and plugging the fuel line.

[bdstone914]

You can tap the inside of the fuel tank fitting to 1/4 pipe thread. You do loose the sock but I would rather have an external filter to trap the dirt and stuff outside of the tank.
Use a 1/4 male pipe x -6 AN.
You could probably install a riser if you could get inside of the tank. The opening is too big for my hands but had my 9 year old grandson reach in to fish out a washer I dropped in one.

[theer]

My "Grey Matter" project will have -AN fittings all around. Tangerine Racing makes the fuel lines with -AN fittings as an option.

[cary]

I have a pair of these on my car .............
http://www.cbperformance.com/product-p/3288.htm

[GrayMatter]

I had thought about the screen. Any reason why I couldn’t or shouldn’t just cut off the fuel line side and install it behind the new fitting?

McMark - you mention don’t use a washer? Not sure I understand why not. The original fittings use them from what I remember. Either way, loctite is a good call and I’ll definitely be doing that.

[GrayMatter]

My "Grey Matter" project will have -AN fittings all around. Tangerine Racing makes the fuel lines with -AN fittings as an option.

I have their hard lines with the -AN fittings and they are great. I too have the -AN fittings everywhere except on the tank.

[GrayMatter]

I have a pair of these on my car .............
http://www.cbperformance.com/product-p/3288.htm

(IMG:style_emoticons/default/smile.gif) I like those better than the ones I found.

[GrayMatter]

You can tap the inside of the fuel tank fitting to 1/4 pipe thread. You do loose the sock but I would rather have an external filter to trap the dirt and stuff outside of the tank.
Use a 1/4 male pipe x -6 AN.
You could probably install a riser if you could get inside of the tank. The opening is too big for my hands but had my 9 year old grandson reach in to fish out a washer I dropped in one.

That was gonna be my next question - how much does the sock and riser really matter if you have good external filters? In my current setup, I have a large NASCAR type fuel filter that sits near my tank with about a foot of -AN line that goes to a -AN to barb adapter to the tank. I’m just looking for easy ways to clean up the look and reduce places where it could leak.

[effutuo101]

I had steel AN bungs welded to the fuel tank. I am running AN fittings throughout (except the connections to the tunnel fuel lines). With the 9mm stainless lines (bought from fellow member here in SoCal) l can push upwards of 70 psi through the system. Since 50 psi is max for my motor, I am pretty happy with the solution. If I decide to upgrade my fuel rail, that becomes super easy as it is the smallest part of the system.

[McMark]

The one issue I have, even if it fits, is the stock fitting has a sock screen and a tube riser that this would eliminate.
The riser stops rust, water (from moisture) and crap from entering and plugging the fuel line.

These can be used with the sock and riser (with the 'lower' portion cut off flush with the 'washer'. Just installed one.

McMark - you mention don’t use a washer? Not sure I understand why not. The original fittings use them from what I remember. Either way, loctite is a good call and I’ll definitely be doing that.

The washers in the stock arrangement are there because those are all that's sealing the fuel inside. With these adapter fittings, the threads are the sealing surface, and the Loctite 565 (which is fuel safe) ensures a complete seal. Furthermore, rubber washers can break down in fuel. The car I mentioned above was getting worked on because the fuel pump died. The fuel pump died because the rubber washer deteriorated and a piece lodged in the pump.

[Phoenix-MN]

You can tap the inside of the fuel tank fitting to 1/4 pipe thread. You do loose the sock but I would rather have an external filter to trap the dirt and stuff outside of the tank.
Use a 1/4 male pipe x -6 AN.
You could probably install a riser if you could get inside of the tank. The opening is too big for my hands but had my 9 year old grandson reach in to fish out a washer I dropped in one.

I tapped my tank for a 1/4npt pipe tread / -AN6 fitting and then fabricated a metal mesh sock to it

[jd74914]

McMark - you mention don’t use a washer? Not sure I understand why not. The original fittings use them from what I remember. Either way, loctite is a good call and I’ll definitely be doing that.

The washers in the stock arrangement are there because those are all that's sealing the fuel inside. With these adapter fittings, the threads are the sealing surface, and the Loctite 565 (which is fuel safe) ensures a complete seal. Furthermore, rubber washers can break down in fuel. The car I mentioned above was getting worked on because the fuel pump died. The fuel pump died because the rubber washer deteriorated and a piece lodged in the pump.

I might not be understanding what you're referencing, so ignore if you are taking about something different, but why do you think the threads on the M18-AN adapters are sealing? If it's still attaching to a non-tapered thread you technically need a sealing washer. I get that you can make it all seal up with some pipe dope, etc. but that doesn't make it correct on a straight thread fitting. Finding a fuel-compatible washer should be pretty easy if the supplied ones have compatibility issues.

[jim912928]

here is a link on how I plumbed my six conversion...shows the gas tank to AN fittings I used ( VW/914 adapters from CB Performance to AN6)...

http://www.914world.com/bbs2/index.php?sho...619&hl=fuel

[Mike Bellis]

I have the CB version on mine and they work great.

[McMark]

I might not be understanding what you're referencing, so ignore if you are taking about something different, but why do you think the threads on the M18-AN adapters are sealing? If it's still attaching to a non-tapered thread you technically need a sealing washer. I get that you can make it all seal up with some pipe dope, etc. but that doesn't make it correct on a straight thread fitting. Finding a fuel-compatible washer should be pretty easy if the supplied ones have compatibility issues.

I agree 100%... with the addition that we're installing two technically incompatible fittings. That adapter is not designed to seal the way the original fitting is. So yes, you could find sealing washers. That's not hard, and if you think that's the way to go, I got nothing but respect for that. But that's also not the 'right way', IMHO. If I was gonna design this part to work 'right', I would spec a fiber washer (probably original) and CAD the fitting with the washer included to make sure there's enough threads to ensure correct crush of the washer.

I think it's presumptuous to assume that this fitting would seat correctly against a stock fiber washer in a way that would create a correct seal. Maybe it does, but I've seen enough adapters and 'custom' parts to be skeptical of making an assumption as big as that.

So rather than spending a bunch of time reverse engineering a stupid fitting, I just added a fuel safe sealant that has to stand up to 0 psi and seal a gap of around 0.01". I think Loctite 565 is well up to the task of those conditions.

But as I said, if you disagree or want to go another way, do it. Just report back here so we can all learn together. (IMG:style_emoticons/default/thumb3d.gif) (no sarcasm)

[Mike Bellis]

I use an annealed copper washer with the CB fittings.