Fuel Line Update
In this article I want to talk about fuel lines again. I touched on this in a previous article and told you that I was experimenting with a new German “Flennor” line. For those of you that missed that article or have a memory like me, I’ll give you a little refresher.
Ok we all have heard from our buddies how they have seen VWs on fire alongside the road. Well this could be from a lot of things but I find the main reason is wrong fuel lines or rotten fuel lines. Let’s touch on the wrong size first. 5mm is not the same as ¼”, 7mm is not 5/16”. So don’t use it. Now let’s look at the construction of the line. The line we want has a woven braid on the outside. American line has a braid on the inside. So what? Look what happens to the line when it swells up from heat. If the braid is on the outside the line can only swell inward. Remember chinese handcuffs? If the braid is on the inside then the line can swell outward (outward and off the fitting) Spraying your engine with gas when its hot is not a good idea. Now the question of, you bought a carb kit and the fittings on the carbs are bigger than the fittings on the fuel pump and they gave you the line I don’t like. What now? Use 7mm line on the carb(s) then with a plastic stepped filter I convert the line down to 5mm (explained better in previous fuel line article).
A lot of us have used the German Continental brand fuel line for years and it has worked well, I personally have used it for years. Here is what I know. When gas was red never ever a problem with them leaking. Now that gas is piss yellow the ethanol will eat rubber when it dries out. If the system stays wet it’s not usually a problem. But if the car sits for any length of time it will become a problem.
So I had been on the hunt for a german line that has the braid on the outside and that the new wonderful gas we have wont eat. Prior to this hunt I was telling customers that if you’re going to let the car sit then use marvel mystery oil in the gas (That still works great FYI). It won’t keep the gas from going bad, but it does keep the ethanol from eating the lines and anything rubber (fuel pump diaphragm, accelerator pumps etc). So I suggest you still use it. It tells you on the instruction how much to use but I just pop the cap and pour some in, about two glugs if that makes sense. Back to my hunt for better line. I found a german brand called Flennor that makes a line that they claim ethanol won’t eat. I wasn’t going to take their word for so I took a length of it and put it in a gas can for about a week. Then I pulled it out and let it sit for six months. I then hooked it to an engine I had on my test stand (pressure side) and looked for leaks as the engine was running. Hey guess what? No leaks. I then started using it on customers' cars, telling them I was using it and to keep an eye on it. To this day we have had no leaks and no problems.
So that is the good news. Bad news is not too many shops know this and getting it is not as easy as getting the Continental brand. I am now carrying both. I special order the Flennor and try to keep it in stock. As the supply gets better I will stop carrying the Continental brand altogether. The other nice thing is that it’s cheaper! We all like that. So there you have it. I suggest if your car sits for a length of time, or if you want to just be extra cautious, switch over to the Flennor German line.