Ok I'm putting the TPI in this week and need to run fuel lines, i figured the easiest and probably safest (fewer connections) is to run one flexible line from the tank all the way to the rail, and same with the inlet just one line, no rubber to har line connectors yadda yadda yadda, so i've heard that braided stainless robs power and retains heat, it's also expensive will some high pressure (250 psi) rubber line suffice, is it tough enough to run down the frame rail of a truck ?? What size should i run, i know the inlet is 16 mm and the return is 14 mm should i swap to AN then its what -8 and -6 correct, which fittings are easier to find for the fuel hoses, they are rather expensive right, they aren't just a slip over and hose clamp right hahaha, good ol carburetor 6 psi !!

 

You should never run rubber fuel line under a car front to back. Bad idea. Especially at TPI fuel pressures. Were you planning on using hose clamps too?

Braided stainless would be very expensive to do front to back. Your best bet would be factory hard lines. Cheap from a junk yard. I think I paid $15 for mine.

 

I am running a braided and hard line setup on my engine.
I have these AN compression fittings that clamp onto the hard lines on the bottom of the car with braided lines going from there to the fuel rail. on the back of the car, I have braided to a filter to another braided line to the pump and then to the tank.
The return is braided from the body straight to the tank.

Here you can see the braided lines on the rail,


I bought 8 of these compression fittings, they hold really tight onto a straight hard tube, no need to flare the tube either.


We used 4 of these on my friends 82 Trans Am with an LT1 in it, 2 on the rail and 2 on the tank and he ran braided lines all the way to the back.

 

I thought there was hard rubber fuel line that was run front to back on a Horsepower TV car, maybe it was dragstrip only, if these comppression fittings are readily available from a speed shop and are completely safe then i'll just run the high pressure fuel line from the rail down to my hard lines, then use the fitting to tap into that back to the filter and inline pump, then i'll need a rubber line to go to the tank and onto the sending unit, which i will have to have the flare cut off to put the compression fitting on. What about the return line, it doesn't have high pressure correct, so i can just slip the hose over the return fitting on the tank and use a clamp. This is all going into a truck so factory camaro lines won't help. I do have hard lines from the mechanical pump all the way back to the tank, only 6 inches of rubber line on my existing set up, so it shouldn't be too bad to put in the hard rubber.

 

'Compression' fittings that you can get in a hardware store will not hold enough pressure for the high pressure side of fuel injection. I found the hard tube adapters as Jeg's calls them and they look just like the hardware store variety. I just used a flaring tool and tube nuts/sleeves that you're supposed to. Flaring really isn't that hard to do at all.

The problem with the compressioin fittings is that there is not much deformation in the hard line and it can come loose after some use. The little brass piece that goes inside the 2 parts just can't grip the tube enough.

As for the rubber line under the whole car... I can just see it getting punctured by some road hazzard. That's why you wont find any rubber fuel lines under a car. The rubber stuff from the tank to the hardlines happens only after the hard lines are bent upwards away from the ground. Also, don't most rule books say that there must be less than 12" of rubber fuel line on a car? If you really want to do it then by all means... stay away from me!

 

rubber line also puts drag on the fuel and if theres enough of it, it'll lower the fuel PSI. not sure how much is needed to notice a differance though.

 

We used the hard tube adaptors with compression fittings on the 82 for 18 months now and no problems at all. Those things won't come off. We tried to twist it and yank them off and they are on there good. We are running 50psi on the system too.

 

I still think you are pushing your luck with the compression fittings. Don't get me wrong the return side will be fine, it is the high pressure lines that worry me.


Also I found this thread earlier today. It says that the braided stainless hoses are known for breaking down with the oxygenated fuel.

http://www.corner-carvers.com/forums...threadid=10653

 

For the Feed and Return on the Rail, I may just get some new steel fittings and weld them onto the steel lines where the compression fittings are.

That info about the braided lines is disturbing. I am not sure if VA uses the MTBE in the gas..