Fuel lines in a racecar

[madjurgen]

I debated whether to run my hard fuel lines through the passenger compartment or under the car. Due to lack of a fire suppression system in my car for the next year or two, I elected to go with underneath the car.

That being said, I am worried about puncturing a line during an offroad excursion. I'd like to run the lines tucked up in the tranny/driveshaft tunnel. Should I be concerned about heat from the exhaust and tranny in this location?

[Lee]

Hi Jurgen

In the car is safer. Spend the mullah for some expen$$$ive braided lines with teflon core and all the fittings. Even if the car is left outside in a nuclear war, the hoses will keep the car together. I did mine more than 10 years ago. BTW If I had to do them all over again, the only thing I wuld change is to route the lines directly to the trunk, not to the rear wheel well (hi-po fuel pum used to be located at the stock Tii location)...

[madjurgen]

Hey Lee,

The setup you have pictured is exactly how I will do it once I have a fire suppression system installed. But since that wont be for a few years, I'm really against running the lines through the cabin. That and Ive already rashly purchased the hard lines.

I wanted to protect the hard lines under the car, hence trying to shove them as high up off the ground as possible. I just wonder if I need to be concerned about it being hot enough to ignite the fuel.

[BLUNT]

i cant add any advice here but lee thats a beautiful job youve done on that car. did you fab up all the goodies i see???

[bmw1602.com]

I wouldn't run anything but steel braided lines for my fuel....

wait a month save up and get them.

[uxoman]

Are you running a mechanical or an electric fuel pump? I am running an electric fuel pump with my s14 swap and added inertia cut off switch. It's hooked it into the ground of the fuel pump so it would interrupt the fuel in case of an accident or roll over. I was concerned with electric pump continuing to pump fuel even when the engine was stalled during an accident or roll over. It's just an added safety feature.

[neanderthal]

lee

thats a great set of pics i see in this thread. do you have any more of pics of the car. or a link to a blog somewhere?\

id appreciate it.

cheers.

[ToddK]

I have always run a hard line inside the car cliped to the tranny tunnel. It is the safest place in the car. If you run one continuous length, how exactly are you going to have a leak? Braided hoses are nice, but they can puncture and leak. They are designed not to burst, not to not ever leak. I'm a Plumber, so trust me on that one. Most of my cars have had the pump, filter and a gauge in the trunk, before changing over to hard lines. Once in the engine bay, I will have a regulator, another gauge, and a braided hose running back to the dash for a gauge. I run higher than needed pressure at the pump, then step it down at the carbs. The gauge on the dash reeds the pump pressure. If it drops below 10 PSI and starts to fluctuate, I know I'm low on fuel. I also run my hard brake lines and proportioning valve inside as well. I have never had a problem, and I have totaled three race cars from accident damage.

[peteinjp]

Todd- as a plumber what kind material (alum/stainless) and why. Also how do you make the connection to the soft lines?

[TimMN]

I'd reccomend plain steel over either of those alternatives. Aluminum is too soft and stainless can be brittle. Use double-flare (brake line style) connections to the rest of the system.

Tim

[ToddK]

For automotive hard lines, I always use steel with flare connections at the ends. Flare connections and steel lines can withstand over 2000 PSI. That is why they are used for brake lines. For plumbing purposes, copper tubing is best. That's good to over 600 PSI and it's easier to work with. I'm not sure what aluminum is rated at. On some of the old British cars, copper tubing was used as oil lines, water lines and gauge feeds.

[TimMN]

but not fuel lines. Copper is subject to hydrogen embrittlement when exposed to gasoline. Pressurize that gas and you can have a real problem.

Tim

[TobyB]

Yeah, steel on the passenger's side of the tunnel, in the car.

Braided stainless hose is really rubber hose with steel in and around it.

It's well- protected, and can handle real pressure-

but the sealing element is rubber hose.

t

[Lee]

i cant add any advice here but lee thats a beautiful job youve done on that car. did you fab up all the goodies i see???

Yup. That's a lot of drilling. Easier to do now with laser cutting.

[Lee]

Braided stainless hose is really rubber hose with steel in and around it.t

Such lines do exist and are bulky. I much prefer to use the ones with a teflon core and braiding around it. They are much smaller in overall diameter, and Teflon stays unaltered by fuel. It will never desintegrate as rubber does over time. Teflon will last a lifetime and won't dry up during the winter storage.