fuel line question
 

I've seen a bunch of cars with stainless steel braided fuel lines coming off of the hardline to the carb. How are the ends of the hardlines modified to accept the screw-on fitting instead of the rubber hose+clamp that comes stock? I was thinking about doing the mod to keep fuel pressure more consistent in addition to dressing up the engine bay a little...more shiny metal can't hurt.

Im in the process of upgrading my other RX-3's fuel system. I have the summittracing brand aluminum lines -8 for supply and -6 for return. Still need to purchase the hose ends and sleeves. and I will need to flare the lines. go check out summittracing.com.

The only hose end adapters I cold find were AN to NPT. And sorry if I sound like a noob, but what exactly do you mean by flaring the lines? Is that flaring the ends out? and for what purpose?

bump

This is kind of a pain in the ass on a Niki. The inlet tube measure approx 5/16" which makes it the same as a -5 fitting. That size is used on airplanes but getting fiittings and hoses is a problem. The return tube is easier - it measures a 1/4" so a -4 will work.

I came up with a rube-goldberg solution, but it works.

I used compression fittings that have male NPT ends. From there I used NPT female to mail AN adapters. My inlet side is plumbed with -6 and the return line to the tank is -4.

If you can wait until the weekend I will give you the fitting sizes and part numbers and snap some pictures of what I did.

So far I have had no issues with leaks and the AN fittings make it easier to service the carb at the track....faster that dealing with hose clamps.

I should mention that I have a dellorto, but I would appreciate seeing what you did. Thanks.

you cant use steelbraided lines with AN hose ends without prep work on the aluminum fuel line. you need to tube nuts, sleeves, and flared line plus an adapter. otherwise, just use a regular fuel hose with clamps.

Okay, that's what I was wondering. Thanks.

Here is the AN Fuel Line adapters I used.

Parts LIst:

1 5/16"x 1/4" NPT male compression fitting (inlet)
1 1/4" x 1/4" NPT male compression fitting (return)
1 1/4" NPT female x -4 male adapter fitting (return)
1 1/4" NPT female x -6 male adapter fitting (inlet)

You can get the compression fittings at a hardware store. I got the NPT to AN adapters from Pegasus Racing. You have to cut the barbs off of the inlet and return lines that are on the carb to install the compression fittings. I recommend removing the lines from the carb so that debris doesn't end up in the fuel bowls.

http://inlinethumb43.webshots.com/43...425x425Q85.jpg

http://inlinethumb19.webshots.com/43...425x425Q85.jpg

http://inlinethumb15.webshots.com/45...425x425Q85.jpg

http://inlinethumb34.webshots.com/42...425x425Q85.jpg

I have steel braided lines, AN fittings, Aluminum fuel lines, etc... ordered everything from summit and used 1 less adapter then the pic above. Makes a real neat appearance and remove / reinstall is now super easy.

However, I could not shoot part #'s and sizes off the top of my head. I usually harass the summit guy until we figure it out.

If you have a Dellorto, remove the fuel inlet banjo and bring it to a local speed shop. They *should* be able to get you the right parts.

http://i44.photobucket.com/albums/f1...L/HPIM1081.jpg

Would like to know how you did the fittings on the Niki.....just curious.

Thanks

Aren't braided lines on a Nikki more of a vanity thing than anything else? I mean, it's running less than 4 psi.

I thought about doing it a couple times (hey, no argument - - it looks xlnt) but I was worried that the added stiffness and weight of the lines would eventually fatigue the braised fuel-inlet tubes.

Whole point of the flexible part of fuel line is to absorb movement and vibration, after all.

if it aint go fast, add some bling to it. :lol::lol:

It was a nut and tube (I think that's what it's called). It required the flared end of the solid nikki fuel line to be cut off so the nut and tube would slide on. When you tighten down the nut it crushes the tube onto the nikki fuel line. And then just make sure the opposite side of the nut and tube is compatible to whatever size AN thread you're using.

The steelbraided line also has flex to it as long you don't run it directly to the carb and leave play.

I beefed up my whole fuel system & it's enough to handle whatever setup I throw in there for AWHILE... Feed line is 1/2" and the pump is in there all AN's also. They come on and off in a jiff in case I ever wanted to throw a different pump in there for EFI, turbo, whatever.

Did I mention it also looks good... :) haha

http://inlinethumb19.webshots.com/43...425x425Q85.jpg

^ The gold fitting is nut and tube. There is a small crush tube inside the nut that is closest to you in the picture that you can hardly see. .

Sounds like they sold you a compression fitting that had an AN male fitting instead of an NPT male fitting. Cool....didn't know they made them. You can get compression fittings that have gas pipe male ends but they cannot/should not be used with AN fittings as the angles are not the same. Gas pipe has a 45 degree taper and AN has a 37 degree taper.

I installed braided lines for safety reasons. I race my car with the SCCA. Also I wanted to be in compliance with the local drag strip. They limit the amount of rubber fuel line allowed in the engine compartment and I was over.

The fittings also make carb service easier - such as making float level adjustments. When you disconnect and reconnect rubber lines allot eventually they don't seal very well. Plus this takes longer. It is bad enough to have a carb in pieces at the track between sessions without having to deal with hoses and clamps.

I elminated any "bling" factor by covering the lines with military surplus fire sleeve. It works as an insulator and helps protect other under hood items from being chaffed by the stainless steel braid.

The feed did give me trouble in the beginning with a slight drip. Maybe that's why..??? Who knows. I definatly had to re-tighten it up the first drive after the install when I thought I had done it enough the first time. I'll keep my eyes peeled for that since I'm doing my other car now. I've been running it now for two years with no leakage since.

That's some solid good intel; thanks!

OFF TOPIC: I see you have the AC brakett on. Why not just take it off.

I have these plans of putting the compressor back to actually have working AC...

I have plans of putting a fan shroud back too.

I also have plans of putting the under air dam back on...

MSD direct fire...

blah blah blah etc etc...

That pictures over a year old and none of the above has been done yet, somehow another RX7 entered my life and alot of things w/this one have been put on hold.