TR4/4A TR$ Fuel line from tank

[eyesie]

Hi
The fuel line from the bottom of my fuel tank on my TR4 got kinked and I would like to replace it, however, it is not available from any of the sources I have checked. It would seem an easy piece to duplicate if I could get the correct fittings. Does anyone know the thread type for this? My nut & olive as it is called in the UK have seen better days,& while I am down there I would like to go all new. Any suggestions?
Thanks
Alan

 

[sail]

Not sure it's what you need but VB has both individual pieces and kits: https://www.victoriabritish.com/icatalog/tc/full.aspx?Page=137

 

[eyesie]

I need the pipe coming out of the tank with the u-bend, that nobody seems to stock. I think I have sourced the fittings, I just need to get the pipe now.

Thanks

 

[charleyf]

That line is 5/16". I was able to go to a local restoration shop and buy some nickel- copper line. Easier to bend than steel line but more durable than copper. They sold it by the foot.
Charley

 

[eyesie]

Thanks, good idea

 

[Tybalt]

If you "bend your own" be careful on bending not to get excessive ovalization of the tube cross section in the bend. As the degree of ovalization goes up, the integrity of the tube segment goes down. Best way not to ovalize the bend is to not do an unsupported "bare hands" bending operation. There are few things you can do to minimize ovalization. The first is is to think in terms of of your bend radius and it's relationship to the tube OD. I would recommend a minimum of a 2D bend radius up to a 3D bend radius. In other words your bend radius for your -5 (5/16) tube should in the 10/16 to 15/16 range. As for tube wall thickness, no need to go over .035 but I would be hesitant to go less than .028", .020" for example would definitely fall into the category of what I think of as "Oh Too Thin" due to the difficulty of getting a good bend.

Next is to support the tube during the bending process. One way is to fill the tube with very fine sand and then hand bend over a dowel of an appropriate diameter to get your desired bend radius. Give it a good and thorough cleaning afterward to make sure all of the sand is removed. Another is to use a tube bending tool. If soft enough, you can use an external spring form to support the tube on the exterior surface and again bend over a dowel to your desired bend radius.

Otherwise I would suggest that you use a proper tube bending tool such as the Imperial Eastman 470-FH (my preference) or the OTC 6515 multiple bend head tools. The -5 tube is kind of an oddball and that is why I gave specific models since they cover -5 tubing. Many of the small multi-headed bend tools only address -3 (3/16), -4 (1/4) and -6 (3/8) skipping over -5. These tools will take care of the majority of your tube bending needs for general purpose automotive use. These tools have a forming die that supports the tube wall during bending and a wiping die as part of the handle assembly that makes the bend as it moves along the tube. The exact bend ratio you will get varies with tube size, manufacturer and tool model but for the most part these produce bends that have bend ratios in the 2.25 to 2.75 range.

 

[glemon]

I got a cheapo tube bender from Harbor Freight when I did my brake lines, it actually works pretty well. https://www.harborfreight.com/1-8-eighth-inch-to-1-4-quarter-inch-tube-bender-94571.html

 

[charleyf]

I use two of them. One smaller with about a 7"handle for brake lines and a larger with a 10" handle for the 5/16" and 1"4" fuel lines. Most of the quality in the work comes from the operator not the tool. Lots of patience is needed along with a sharp eye. The really tough one to bend is the rear brake lines located inboard of the brake backing plate.
Charley

 

[KVH]

My recollection is that I replaced the fittings with ones I just found locally at a hardware store. As for bending, I used a good tool from Harbor Freight, and was sure to add a bend so that the line freely moves and won't be jarred hard by bumps or hits. I could send a pic, but I believe the soft fuel line hose from the tank fitting to the larger line has a slight "S" in it so it naturally bends. There should be no pressure on the short line from the tank.

 

[Tybalt]

I use two of them. One smaller with about a 7"handle for brake lines and a larger with a 10" handle for the 5/16" and 1"4" fuel lines. Most of the quality in the work comes from the operator not the tool. Lots of patience is needed along with a sharp eye. The really tough one to bend is the rear brake lines located inboard of the brake backing plate.
Charley

So true that how the job turns out is primarily a function of the care taken in doing the work. The tricky ones are long tube runs with multiple bends where you have to get the bend in the right place to the correct angle and get the bends properly clocked. The standard one coming off the fuel tank is fairly simple but for those tricky ones, I've been known to get some soft aluminum (3003 in an O condition) tubing and make a mock up then check the mock up against the application. The 3003-O bends way easier and costs very little compared to the 316L or 321 austenitic stainless steel or 6061-T4 or 6061-T6 aluminum that I typically use for the actual tube. Even then using the 3003 mock up has to be treated with some degree of caution when used as a model for steel, stainless stell and titanium. With those materials you run into considerably more springback that with aluminum so you have to over bend it a bit to take care of the bend angle, bend radius and distance between bend differences that springback introduces.

 

[BL50]

So true that how the job turns out is primarily a function of the care taken in doing the work. The tricky ones are long tube runs with multiple bends where you have to get the bend in the right place to the correct angle and get the bends properly clocked. The standard one coming off the fuel tank is fairly simple but for those tricky ones, I've been known to get some soft aluminum (3003 in an O condition) tubing and make a mock up then check the mock up against the application. The 3003-O bends way easier and costs very little compared to the 316L or 321 austenitic stainless steel or 6061-T4 or 6061-T6 aluminum that I typically use for the actual tube. Even then using the 3003 mock up has to be treated with some degree of caution when used as a model for steel, stainless stell and titanium. With those materials you run into considerably more springback that with aluminum so you have to over bend it a bit to take care of the bend angle, bend radius and distance between bend differences that springback introduces.

Wow, lots to consider when running a new fuel line. What material do think is best for a TR4A restoration?

 

[Tybalt]

Wow, lots to consider when running a new fuel line. What material do think is best for a TR4A restoration?

The original material used for the fuel line from the factory was just your basic mild steel. Since these cars don't really see daily driver use for the most part these days, you could use that (corrosion isn't that big a deal for the mild steel fuel lines on occasional drivers) or you could use one of the 3xx series of austenitic stainless steels. While from a "would it work standpoint," you could consider aluminum, I'm not big on that for the fuel line that runs under the car. Call me paranoid, but I'd rather have something for a fuel line under the car that is more damage tolerant.

In any event you want it in an annealed condition, especially if you go with the austenitic stainless stuff. These materials strengthen through work hardening and as you make the bends, you are work hardening the material to some degree in the area of the bend. If you start out with tube stock that has already been work hardened, it's much more difficult to work with and it also means that that your bend radii need to be larger due to the reduced elongation that results from the higher strength. You can somewhat account for the shorter elongation or using a smaller bend radii by going to thicker tube walls, but again, that will make it even harder to work with as you are moving more metal around. Remember that if you think in terms of the hoop stress and other mechanical loads on the tube, the calculations will almost always show that you can go with some rather thin walls. The other side of the coin is that you generally need that extra wall thickness so that you can actually form the tube and not because of strength requirements.

 

[MichaelG]

Did you Check TRF? I thought they will supply most any brake/fuel pipe for the TR4 pre-bent.

 

[BL50]

Did you Check TRF? I thought they will supply most any brake/fuel pipe for the TR4 pre-bent.

Very hit & miss ... Moss carries some, TRF carries none.