I'm thinking of pulling my factory hard line and duplicating it in double wall stainless, I think I can go just a bit bigger and have it still fit the factory clips, the stock fuel line is probably adequate, but after 25 years it's probably due to be replaced, plus is most likely restricted by varnish deposits by now. I have the bending tools and AN flaring tools to change the line to AN flared on both ends

 

bump, dont mean to bring back something from years ago but im having a similar issue with my ef, i dont know if should run the an lines inside like the old stock lines, use the stock lines and just connect an fittings to them or run the lines outside, and if i do run it outside whats the best place to place them at? im using a bosh external 044 pump

 

I've run earls an lines in numerous cars, including our c6 z06 track car, my s13, my civics, and countless other cars at the shop.

never once have I had them leak fumes, ever. it's normal when the lines are first installed and pressurized for a small amount of fuel to leak past the pins in the fittings but after a few pressure cycles it stops.

this makes me think that either your lines aren't properly seated to the fittings all the way or you are running the wrong material braided line for fuel use. most lines for fuel should have a Teflon liner which prevents any vapors from leaving the lines.

the race cars we've built run the lines inside the car with a manual fuel shut off valve as required by sanctioning bodies. the reasons for running them inside the car are numerous but the main reason is to eliminate the chances of a line being punctured by track debris or an off course event or having a line rub through due to ride height or going off course.

we've never had a smell problem.

if your vent is inside the cockpit then that's just dumb and unsafe. it should be ran outside the car with a check valve to prevent fuel leakage in case of an accident or rollover. depending on where the vent exits the chassis it isn't uncommon for the vapors to enter the cockpit through the air flow flaps at the rear of the car, similar to how depending on exhaust routing you can smell exhaust fumes because they leak into the cockpit through those flaps. this is very well what you could be smelling.

 

Wait really? I just fell victim to an old thread bump?

The way the lines are routed is entirely up to you. having the lines inside the car protects them from being damaged from any road debris. Honda ran the lines inside for a reason, it could be there isn't a way to run the under the car due to chassis design or tank design. you might not be able to run them in the tunnel because heat from the exhaust can cause vapor lock within the fuel line.

 

I know this was an old thread but to help i had this issue with the braided AN lines when i used the rubber stuff. I switched to PTFE overbraided lines with PTFE AN fittings (use an olive in the end) and these dont smell inside the car. Were not allowed to use the rubber overbraided lines inside a car over here. PTFE from the likes of Goodrisge is the only way for us legally

 

Yea the rubber lines were really designed for oil, using those for fuel will cause a fuel smell in the car and depending on what fuel you run it can cause the rubber inner to disintegrate. the Teflon is what you need for fuel because it's chemical resistant and doesn't allow vapors to seep through the lines like you said.

use the right part for the right purpose and most issues go away.