need some advice, running 3/8" fuel line, how to run, what to use

[roylerumble]

Im trying to plumb new 3/8" fuel line to my 69 valiant, 408 stroker. upgrading to a 3/8" line, with a high flow mechanical fuel pump. Tried bending a metal line in the factory location, but the 90 degree tight bends at the rear wheel well are tricky and we crushed the tubing. Question(s) is/are.... is there a better place to run the line? Should I bite the bullet and go with an AN soft line? Depending on how it runs, I may add an electric pump in the future if needed, so would it be best to run it close to the tank? I have a front and rear RMS suspension. I plan on installing 1 1/2"x 3" subframe connectors and thought about running the soft line through the frame and the connectors. TTI ceramic coated exhaust. I'm trying to think ahead too. I'm in Canada, so it doesn't get to hot, so most of the guys up hear don't think a return line is necessary at this point, but I'd like to make provision for one, if needed. Any suggestions or areas of concern? Pics would be nice.

 

[72bluNblu]

I run a 3/8" stainless line on my Duster. I just bought it from Inline Tube, it follows the factory routing and was pretty easy to install. I have 1.5"x3" subframe connectors and they don't really interfere much with the original routing.

With 5/16" tubing you can make bends pretty easy with just a cheap bender, but with a lot of the 3/8" lines (especially stainless) making accurate bends gets more difficult unless you spend money on a nice bender. Pick your poison I guess, I just bought the stainless 3/8" line.

 

[roylerumble]

I run a 3/8" stainless line on my Duster. I just bought it from Inline Tube, it follows the factory routing and was pretty easy to install. I have 1.5"x3" subframe connectors and they don't really interfere much with the original routing.

With 5/16" tubing you can make bends pretty easy with just a cheap bender, but with a lot of the 3/8" lines (especially stainless) making accurate bends gets more difficult unless you spend money on a nice bender. Pick your poison I guess, I just bought the stainless 3/8" line.

$99 for a 3/8" line? that's awesome provided it fits. Only problem is shipping. Would prob have to give up a left testie or my first born to get it to the great white north.

 

[65-440]

I ordered the 3/8 pre Bent fuel tubing from summit, was from right stuff detailing. Order Over $100 and it ships for free. Install was a breeze

 

[Hellrats]

There is a type of brake/fuel line that bends easy, doesn't kink and doesn't rust. It is called Cunifer. Google it, you can buy it at most auto parts stores. This stuff works great. Very nice if you are making custom stuff.

 

[Max1196]

You didn't say, what type of line are you working with right now? Steel, stainless or aluminum?

 

[rklein383]

I have done it two ways with success. In my 69 383-s, I bought some aluminum fuel line and bent it by hand and routed it along side the original 5/16 fuel line and used heavy duty zip ties to secure it. That was on the car for 20 years.

My latest project, I tried bending the fuel line myself...big mistake. The curves are many and although I tried to mimic the original 5/16, it just didn't come out. I then bought prebent fuel line, stock material, and it fit perfect. I would highly recommend buying it prebent. Rod

 

[famous bob]

I have done it two ways with success. In my 69 383-s, I bought some aluminum fuel line and bent it by hand and routed it along side the original 5/16 fuel line and used heavy duty zip ties to secure it. That was on the car for 20 years.

My latest project, I tried bending the fuel line myself...big mistake. The curves are many and although I tried to mimic the original 5/16, it just didn't come out. I then bought prebent fuel line, stock material, and it fit perfect. I would highly recommend buying it prebent. Rod

View attachment 1715142229

You guys know there are flexable rubber fuel lines made for fuel inj. hi/pressure and any kind of fuel now, that`s even accepted for the nhra, don`t you? All u need to do is run it away from any heat and away from anything that will explode. Nothing on the firewall either.

 

[67Dart273]

I but the 90 degree tight bends at the rear wheel well are tricky and we crushed the tubing.

What are you using for a bender? If it's not an all metal name brand traditional bender like Imperial, etc, you are wasting your time.

Don't beat yourself up. I would not be adverse to ordering a repop 3/8 tube, and there is stainless braided teflon options as well. I WOULD NOT RUN rubber unless it has a stainless inner braid

These types here.......come in various forms, more or less expensive, more or less "strong" some are single size and some stepped like this one

 

[roylerumble]

I run a 3/8" stainless line on my Duster. I just bought it from Inline Tube, it follows the factory routing and was pretty easy to install. I have 1.5"x3" subframe connectors and they don't really interfere much with the original routing.

With 5/16" tubing you can make bends pretty easy with just a cheap bender, but with a lot of the 3/8" lines (especially stainless) making accurate bends gets more difficult unless you spend money on a nice bender. Pick your poison I guess, I just bought the stainless 3/8" line.

yeah the 38" stainless doesn't bend nice. I have several sets of benders. Yesterday I went and grabbed a 3/8" spring and a big bender with several dies. If I slide the spring on and use the bender, it seems to keep the integrity of the tubing wall. I tested it with a scrap of the line that I had from our first blunder.

That being said, $100 from summit or the other vendors, even with the exchange rate, seems like a better deal than screwing up another line.

 

[roylerumble]

There is a type of brake/fuel line that bends easy, doesn't kink and doesn't rust. It is called Cunifer. Google it, you can buy it at most auto parts stores. This stuff works great. Very nice if you are making custom stuff.

I checked out Cunifer. I think that's what my 5/15 brakes are bent out of. Only $129 for a 25 ft roll on line. I think I found it locally and they want about $5 to $6 a foot.

 

[roylerumble]

What are you using for a bender? If it's not an all metal name brand traditional bender like Imperial, etc, you are wasting your time.

Don't beat yourself up. I would not be adverse to ordering a repop 3/8 tube, and there is stainless braided teflon options as well. I WOULD NOT RUN rubber unless it has a stainless inner braid

These types here.......come in various forms, more or less expensive, more or less "strong" some are single size and some stepped like this one

thats the set I used. I found if i used a spring over the stainless tube, and then used a large die on a new set of benders I picked up, it worked well.

 

[roylerumble]

You didn't say, what type of line are you working with right now? Steel, stainless or aluminum?

Stainless, but Im not hell bent on any material. I know there are pro's and con's to all of the options.

I'm not also set on running the factory location. As I mentioned, I elimitated the springs, tortion bars, and I'm adding home grown subframe connectors.

 

[72bluNblu]

yeah the 38" stainless doesn't bend nice. I have several sets of benders. Yesterday I went and grabbed a 3/8" spring and a big bender with several dies. If I slide the spring on and use the bender, it seems to keep the integrity of the tubing wall. I tested it with a scrap of the line that I had from our first blunder.

That being said, $100 from summit or the other vendors, even with the exchange rate, seems like a better deal than screwing up another line.

That's the conclusion I came to. It's not like there's a couple bends, there's quite a few. And when the line starts taking on a 3 dimension shape with the bends not all occurring in one plane it gets complicated. Then you test fit, adjust bends, add more, by the time you've made the whole line the time spent doing it is probably worth the cost of the pre-bent line. At least it was for me.

I'm not a fan of running soft lines, the fuel additives change enough that you can't always count on a soft line's long term resistance to the fuel. And there's different qualities out there, even with just the 3/8" sections of rubber line at either end of the hard line I've had issues. I just had the 6" section of line between the sender and the hard line split, it was only 5 or 6 years old.

I figure the stainless hard line will last as long as I have the car, it won't rust, the fuel won't ever attack it, and I only have to buy and install it once.

 

[69_340_GTS]

I have used braided stainless steel AN-6 hose on a few cars for the complete fuel system. Get the good stuff (Earl's, Russell, Aeroquip) and it will not rot. The stuff they are making now is compatible with today's fuels.

 

[JoesEdge]

Hey guys...just jumping on this thread since it's related...

When going from 5/16 to 3/8 fuel line, what do you use to hold the fuel line down? Can the original hardware be used?

I looked at the brackets on the rear frame rail of my duster, and I didn't think that they can be reused because of the difference in tubing diameter. The bracket is holding down both the fuel line tubing and the gas tank breather line tubing.

I would imagine that reusing the hold-down brackets will end up with a loose breather line tube.

So I wondered what you guys did. Do it require the right size brackets to be purchased?

 

[roylerumble]

Hey guys...just jumping on this thread since it's related...

When going from 5/16 to 3/8 fuel line, what do you use to hold the fuel line down? Can the original hardware be used?

I looked at the brackets on the rear frame rail of my duster, and I didn't think that they can be reused because of the difference in tubing diameter. The bracket is holding down both the fuel line tubing and the gas tank breather line tubing.

I would imagine that reusing the hold-down brackets will end up with a loose breather line tube.

So I wondered what you guys did. Do it require the right size brackets to be purchased?

classic industries has a set of clips for 3/8" fro $13

 

[65-440]

I went from 5/16 to 3/8 on my 68 coronet, used the factory clips with no problem ...

 

[space duster 383]

I r

I went from 5/16 to 3/8 on my 68 coronet, used the factory clips with no problem ...

an 3/8 SS, not once but twice. The bends didn't get me, the double flares did. I highly recommend not using SS if you have to do your own flares. I went through two flare kits trying to get a double flare I could trust. Finally went with SS braided from Holley up from the mechanical pump to the area in front of the water pump. From there it is all aluminum fittings from Summit and some from Holley. I put a Holley filter in the line from the water pump area to the double pumper dual feed with a fuel pressure gauge. I'm satisfied with my set up, but I nearly had a serious problem with a SS flare leaking over the intake manifold and the pan. My fault, not the material's, but don't take short cuts with the SS line if you use it.

 

[72bluNblu]

I r

an 3/8 SS, not once but twice. The bends didn't get me, the double flares did. I highly recommend not using SS if you have to do your own flares. I went through two flare kits trying to get a double flare I could trust. Finally went with SS braided from Holley up from the mechanical pump to the area in front of the water pump. From there it is all aluminum fittings from Summit and some from Holley. I put a Holley filter in the line from the water pump area to the double pumper dual feed with a fuel pressure gauge. I'm satisfied with my set up, but I nearly had a serious problem with a SS flare leaking over the intake manifold and the pan. My fault, not the material's, but don't take short cuts with the SS line if you use it.

Those cute little flare kits are just about impossible to use for anything stainless and even standard materials for tube larger than 5/16". I gave up on those and bought one of these
Professional Brake Tubing Flaring Tool - Eastwood

Yeah, it's expensive. But it works every single time, does 3/8" stainless no problem. And I've already used mine enough to make it worthwhile. I usually buy the full length prebent fuel lines just because of how long they are and how many bends they have, but I make a lot of my brake lines because bending/routing them is pretty easy.

 

[65-440]

Those cute little flare kits are just about impossible to use for anything stainless and even standard materials for tube larger than 5/16". I gave up on those and bought one of these
Professional Brake Tubing Flaring Tool - Eastwood
View attachment 1715142485

Yeah, it's expensive. But it works every single time, does 3/8" stainless no problem. And I've already used mine enough to make it worthwhile. I usually buy the full length prebent fuel lines just because of how long they are and how many bends they have, but I make a lot of my brake lines because bending/routing them is pretty easy.

Exactly, stainless line requires a tool made for the job ... those small hands held flare tools will not do it, I'm pretty sure they even say that in the instructions !

 

[Max1196]

I gota add this. Not me, my buddy, Don't forget to put the fitting on before making the flare!

 

[JoesEdge]

classic industries has a set of clips for 3/8" fro $13

Are you referring to these, because they are far from $13.00 bucks! Yikes! 32 bucks??

1974 Plymouth Duster Parts | MN2300 | 1970-74 Mopar A-Body Fuel Line Clips 3/8 9 Pieces | Classic Industries

Do you have a link to the ones that you're referring to?

I went from 5/16 to 3/8 on my 68 coronet, used the factory clips with no problem ...

Maybe they are different on a '68 Coronet? I don't know what your clips look like. I believe mine are similar to the ones in the link I posed above from Classic Industries.

 

[roylerumble]

Are you referring to these, because they are far from $13.00 bucks! Yikes! 32 bucks??

1974 Plymouth Duster Parts | MN2300 | 1970-74 Mopar A-Body Fuel Line Clips 3/8 9 Pieces | Classic Industries

Do you have a link to the ones that you're referring to?



Maybe they are different on a '68 Coronet? I don't know what your clips look like. I believe mine are similar to the ones in the link I posed above from Classic Industries.

1969 Dodge Parts | MN2298 | 1963-69 Mopar A-Body Fuel Line Clips 3/8 7 Pieces | Classic Industries

 

[Deucemopar]

I have used braided stainless steel AN-6 hose on a few cars for the complete fuel system. Get the good stuff (Earl's, Russell, Aeroquip) and it will not rot. The stuff they are making now is compatible with today's fuels.

Agree. Even the PTFE stuff isn’t too expensive anymore.

AN Hose - PTFE Lined - Bio-Fuel Fluid Type

The fittings can be a PIA. Just get the right tool.