[travis]

Well, I may have found a way out of trying to build a new fuel line (the one on my car is smashed nearly flat right at the s-curve around the front of the leaf spring eye). I am kicking myself for not checking this a long time ago. My 6 banger nova parts car, which I assumed had a 5/16" fuel line from the tank forward, has a 3/8" line, identical to the V-8 setup. Only problem is that to replace the fuel line as 1 piece, I have to remove the sub frame connector AGAIN and drop the front of the pass. side leaf spring AGAIN. This is really a PITA to do, by the way. And it still may not work because of the exhaust system and everything else in the way. On the parts car there was no exhaust, tranny, etc so I had all kinds of room to wiggle to whole fuel line out from under the car. Anyway, as I was thumbing thru a older car mag the other day, I found a little article that showed some Aeroquip parts called Versi-flare. Basically, it uses a tube nut and a 37 degree ferrel and tightens down on something like a bulkhead connector (also 37*) to form a patch that requires no tube flaring. I would really like to use a setup like this...problem is I can't find this stuff anywhere. Maybe it's under a different name now? Does any other company make a similar product? Has anybody ever tried this?

[SY1]

Travis,

I have spliced together and also built fuel lines using a double flare tool and inverted flare unions. I know most auto parts stores carry a good selection of brass fittings, including the inverted flare fittings. They are just a square brass block drilled and tapped to accept the tube nuts and at the bottom of the bore has a 37 degree inverted flare to mate to the 37 degree flare on the tube. This is the safest connection in my opinion because the threads are not doing the sealing, the flare on the tube and inverted flare in the fitting are. You still see some guys putting teflon tape on the tube nuts but it isn't necessary because it has no effect on the seal if they've mated the flare properly. I know I bought some inverted flare unions as well as tee fittings to use on dual inlet holleys when I've made fuel lines for those set ups.

Dave

[Eric68]

Sorry I can't help with the Aeroquip parts question, but why not just bend a brand new line from straight line? Your local parts store carries various length tubing and brass couplings, you could probably use 2 or 3 pieces and not even have to cut and flare any of them.

I've only bought 1 pre-bent line for my Camaro (the fuel line ironically) and even though it came bent correctly it was a real PITA to install because it was so long and had to go through so many tight spots. Since then I have made all my own lines and have replaced all the brake and trans cooling lines using shorter pieces and flare couplings.

I suggest this because removing and reinstalling a used fuel line sounds like a "gasoline bath" waiting to happen.

ps. You know a short piece of braided line and a couple clamps might make a good patch if you want to salvage your existing fuel line.

[BPOS]

Is there any reason why a brass compression union wouldn't be advisable for fuel line? I used them when I made my trans cooler lines, and they worked great -

[SY1]

I think the compression fitting would work good on an aluminum line like Moroso sells. I'm not sure how well the sleeve would draw up into a steel line. The only other thing would be the compression sleeve will restrict the line slightly due to the design as it draws into the tube. It's certainly a simplier solution than double flaring lines.

[davidpozzi]

All second gen's use a short piece of hose just forward of there to allow for flex of the subframe to body. The 37 deg flare with a backup piece in the flare nut works best and avoids the dreaded double flare.
You could order a short piece pre-bent from Classic tube and just get the section you need with flares on each end allready done.
David

[Mark C]

i don't believe you need a double flare on a "STOCK" fuel system line. With the normal mechanically operated pump the line between the tank and the fuel pump sees a negative pressure (vacuum) as the fuel is sucked from the tank by the pump. You can get a peice of 36 or 48" long 3/8" fuel line at you local Pep Boys, NAPA, or Auto Zone. Bend it up to fit your car using a tubing bender, cut one end of it off to get the union fitting off one end and attach it to the sending unit pipe with a short peice of fuel line just like the original system did. The opposite end could either be coupled to the existing fuel line with a compression fitting, or you could use another short piece of tubing and a couple of hose clamps. Or you could slide a 3/8" flare coupling on the original line where you cut it and then flare it so you could use the fitting supplied on the new tube.

It only needs to be tight enough to keep fuel from dripping when the engine isn't running and fuel is just sitting in the line. All the original lines are attached using rubber tubes and hose clamps between the fuel tank and the pump.

Of course if you have an electric pump installed at the tank you need to hard pipe the entire system with flared connections as the line does see a lot of pressure.

The only lines in a car that use a bouble flare is the brake lines.

[SY1]

Hoses and hose clamps are used at both the tank and the fuel pump inlet for reason that both David and Marc have stated. The end of the hard lines are beaded or bulbed to help retain the hose without over tightening the clamps. Most people don't have the tools for bulbing the hard lines so often you'll see the clamps overtightened in an effort to help keep them from sliding or being pulled off the hard line. This is what damages the hoses and leads to leaks over time.

I'm also pretty certain the factory fuel lines I've worked with are double flared as well as the brake lines. In fact almost everytime I've seen a tube nut untilized the line has a double flare on it. I've been making all my own for quite some time and I just double flare them because I've got the tools and it's become pretty easy to do with some practice. I'm not saying it's necessary, but I have seen many single flared lines split at the flare, so I just automatically double flare everything. It may not be necessary, but it doesn't hurt. I know of a large mod center for jet aircraft in San Antonio that still tries to use single flared stainless lines on 3000 psi hydraulic and thrust reverser systems. I can't believe the FAA allowed it, I've changed many of their lines due leaks from cracks in the flares. There are so many better fitting like MS fittings that should be used in that kind of high pressure system. But this does show that a single flared line if not cracked will hold up to some pretty high pressure.

But I've got to agree with Marc, get some tubing and make you own lines, it's easy and you can bend them to fit just the way you like. Buy a little extra, if you're like me you'll screw up once or twice before you get the bends just the way you want them. I tend to do things that are overkill, but it's my nature after 20+ years in aviation maintenance. So no you don't need to double flare, there are easier ways to build a fuel system like the guys and my last post are saying.

[BPOS]

As long as we have some experts on this one, I'd like to get your opinion(s) on the use of aluminum tubing for the fuel line. It sure is easier to bend, but I wonder about durability and fatigue. I seems to me that if it securely clamped along its length, fatigue wouldn't be an issue. And as long as we're talking about it, how about copper tubing?

Thanks, guys.

[Eric68]

I wouldn't be as worried about fatigue resistance as I would impact resistance. I think steel lines would hold up better during a crash than copper or aluminum.

Just my opinion.

[SY1]

I agree with Eric. Aluminum is certainly easy to work with, but be careful what you clamp it with also. I wouldn't use steel clamps due to the aluminum line is going to lose when they chaf and dissimilar metal corrosion will be another problem. If you use rubber cushion clamps you wouldn't have any problems. I think you'd want a lot of the gravel guard coil that the factory put over the steel lines at certain location because the problem of road damage will be worse with the softer aluminum. A lot of guys use the Moroso aluminum line on race cars, but you still have to consider crash worthiness.