LS1 Fuel Line Install

I just wanted to show what I did on Vorsche's car for the fuel lines. I used nylon hose end splices for the connections to the filter for easy change outs. I put it right where the old coil used to be. The lines are ran between the finder liner and metal inner fender. They are secured and protected here.

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Hey Eric, where did you procure those push on inlet fittings from?
The stock fuel line fitting is a female inverted flare M16 x 1.5 and I want to just connect to that and install my C5 filter/regulator where I ripped out the Cruise Control Crap.

Those lines are at Napa and autozone and such. Called nylon fuel line repair kit. About 15 bucks.

Yes, what he said!

Specifically the push on connectors. Do they come with the Nylon lines?

It came with everything you see in the picture for each tube. The connectors and barbed ends. the connectors were install on the lines, but the barbed connectors had to be install by me. Th lines were straight also. I bent them by heating them with a heat gun.

Interesting, variation on our cars. I have not one line of any kind that heads off to the left, fuel or otherwise. They all head straight down.

Which fuel line is pressure vs. return? Both of mine go directly to the porsche fuel rail.

with enough cussing and screaming yours to can point to the left . I don't remember which is which at the moment. On the Porsche fuel rail , the hose that has just hose clamps on it is your return line. the line with the screw on and crimped on fitting is your pressure line.

I forgot which of the lines on the filter do what. Is the middle pressure or return on the end that has the two lines on it.

As a general rule of thumb, a pressure line is always going to be smaller than the return line. This is true for fuel lines, hydraulic lines, A/C lines, etc. I believe the Filter body also has flow directional arrows embossed on it as well.

For my fuel lines I just cut off the bulb flares on the Porsche lines and installed a compression fitting from Dorman Products. It is similar to the compression fittings you use on copper water lines in your house. The other end of the Dorman fitting adapted to the standard flexible Nylon hose that was used on the Corvette's and then a standard GM fitting on the end of that adapted it to the push fitting on the Corvette style fuel filter. I couldn't find the Dorman fitting at my local store but I called their Tech Center directly and their guy was very helpful. He was an ex- LS1 test Technician from GM and sent me, free of charge, a sample of many different fittings and tools with which to try. Can't ask for better service than that!
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it is the reverse of what you said about the lines, on the stock porsche the bigger 10mm line had the screw on to the fuel rail and the 8mm line just had a corkscrew clamp on it. Wouldnt that make the bigger line the pressure and the smaller the return?

That is atleast how my 86 turbo is setup.

Nice work, i definitely should have done something like that!

"it is the reverse of what you said about the lines, on the stock porsche the bigger 10mm line had the screw on to the fuel rail and the 8mm line just had a corkscrew clamp on it. Wouldnt that make the bigger line the pressure and the smaller the return?"

Maybe I am mixed up. My rules of thumb perhaps only apply to closed systems. Fuel would be consumed, so the volume would decrease allowing for a smaller tube size. That might make some sense. Anyway, on my car both lines were screw on, but mine had the Bosch J-Jetronic system whereas yours had the Bosch I-Jetronic, so there would be differences.

I guess the best way to tell might be to disconnect the pressure line from the original fuel filter beside the fuel tank and run some compressed air through it and then see which open tube has the air coming out. Or, if you are daring, hot wire the fuel pump for just a second (into a catch can of course).

thats how I figured mine out in the end. I used a wattle bottle on each line and turned on the key. it works.