SovXietday

Hey guys.

Well I am in the process of putting AL hardlines on my car. I am aware of the issues that come along with that, and I also know that quite a few people have no issues at all with them.

-Car will be running on ethanol (E98) and will get flushed with 93 before prolonged sits (2 weeks+)
-Lines on body will all be supported with cushion clamps every ~12". All connections will be hardline except for the body to motor span. Fuel cell, fuel pump, and filters are all going to be solid mounted to the car, no straps.
-Fuel rail lines are all supported from the motor and are under 12" total.





Is what I have done correctly limiting the chances of cracking due to vibrations? Would you do anything differently? I do not want to run braided lines beyond what I have now.

I do not think the tools I have are capable of bending stainless in these sizes, that's mainly why I am sticking with AL for now. Input is appreciated.

torkh22a

Is the regulator mounted to the body? Personally off at all possible I'd try to mount the reg on the power plant so you wouldn't have to worry as much about the engine vibration vs body vibration

tepid1

You'll be fine. Just pay attention to the fittings coming loose over time. Check them periodically.

Nice work!

SovXietday

Regulator is bolted to the engine. Two feeds feed into it from the rails, and then flex line to a bulk fitting on the front subframe.

Awesome, good to hear. Thank you.

that-guy

so long as everything in relation to the hardlines is moving at once, you should have no problem. since your reg is bolted to the motor, the lines will never be under any strain

jj07

Most of the AL fuel line ive seen is only low pressure stuff. Where are you finding the high pressure stuff for FI?

SovXietday

Honestly, I have no idea where they are getting a 25-35psi rating for aluminum tubing. Stuff, in the same thickness, is rated for 1300psi in aircraft applications. Even if it's a lower annealing it will still hold a hell of a lot of pressure. New cars use plastic fuel lines now, lol. Burst under high pressure is not at all a concern.

Either way, speedwaymotorsports sells the same thing that JEGs/Summit sells, rebranded of course, and it's rated for 250psi.

http://www.speedwaymotors.com/Alumin...-OD,34277.html

Thanks for the help guys, onward with my project lol.

Def

If you used at least 0.035" wall thickness 6061 aluminum, it will be good for at least 100 psi with a significant safety margin.

Fighter jets use 0.028" in most of the lines that size and will run those tubes up to ~130-150 psig with a small safety factor. That's including structural vibrations and material fatigue of 8,000 flight hours. So once you get to 0.035" wall thickness in a ~1/2" size, you're golden on any fluid in a car.

that-guy

truth...plus, in aircraft applications, especially fighter jets, they are pulling 1-8g's in flight, where the pressure would thin out the fluids and cause the lines to potentially colapse. so i say that if they can use something like that, than a car, which won't need nearly as much pressure, will be more than fine

wantboost

iTrader: (2)

how hard are you finding it to bend tight radius pieces without crimping/collapsing? I'm about to start on something like this as well

SovXietday

Let me put it this way, if you don't have a bender, it's going to collapse and kink. Your bender is going to dictate your radius, and the tight radius large diameter tubing benders are $$$.

Soooo my advice is give yourself room to make normal bends lol.