leaderman

Hello and thank you for your help. You guys have been great when I need help and I sincerely appreciate your time/knowledge. I have a 1994' Z28 that I'm installing nitrous on and I have a question about Teflon tape? All the articles I read say don't use it on nitrous, and then I come across some articles that say your supposed to use it on your NPT fittings only (like hobbs switch, etc...). What's the deal? I realize your not supposed to use it on your -4AN fittings, but what about the NPT fittings?? Also, if I am supposed to use it (and not much of it so it doesn't clog up thee jets) on the NPT fittings is it supposed to be the yellow Teflon tape for gas instead of thee regular white Teflon tape?? Also can I use small copper washers for the -4AN fittings to seal them up better?? I am using a wet kit so I don't want any leaks anywhere?? One more question. I have to screw the -4AN braided wire fitting on top of the fuel rail towards the rear of my engine and I'm worried that there won't be enough clearance and I'll have to bend the braided line to much to get it to work? I am thinking of getting a -4AN female to male 90 degree swivel fitting but I heard some people have a problem with them leaking?? Should I severely bend the braided line or just buy the 90 degree swivel fitting and not worry about the leaking?? There are just so many breaks in the lines for all my "goodies" that I'm worried about it leaking ether fuel or N20 gas?? Should I just tighten all the fittings properly (tight, but not tight enough to strip) and just not worry until I have a reason to worry?? Or try the correct size copper washers throughout?? Sorry about all the babble.... I'm a newb.....

-Chris

Injuneer

With regard to the sealants, do not put anything on the "AN" portion of a fitting - no teflon, no gasket. The mating conical surfaces provide an excellent high pressure seal - your nitrous lines run at up to 1,000psi (or more - careful) - I have never had an -AN fitting leak. Adding a copper gasket would prevent the conical surfaces from seating tightly against each other.

With regard to NPT threads, the use of teflon tape is often discouraged, because if you get the tiniest remnant of tape in the line, it's going to plug the solenoids or the jets. But, if you know what you are doing, teflon tape works fine on nitrous lines. But it's easier to use a teflon paste and avoid the possible problems.

Do NOT make a sharp bend in the braided S/S line. Not only do you run the risk of damaging the S/S line, you also run the risk of breaking the Schrader valve on the hard fuel line off. It is just swaged on, and will break off with any bending moment, or simply from over-tightening the fitting you attach to it. -AN fittings do no require huge torque to seal. Just past hand tight is adequate.

My solution is a -4AN 90-deg swivel fitting. Will it leak..... no. Used them for years, never a leak. The 90-deg fitting allows you to point the connection off to the side, rather than up at the cowl, and the swivel allows you to point it horizontally in any direction you need, without over-tightening it. I think the NOS part # is 17585.

slick1hunting

I agree with fred. I bought my car with kit installed already and they spliced the fuel line about the middle of the manifold and put a t and put the hobbs switch there. None of that has leaked either and I think I personally prefer that. I just did some fuel pressure testing and let me tell you the connection on the schrader valve was very difficult to find the sweet spot to allow the valve to open and accurately moniter pressure. Was a rental tool so something of higher quality probably not this kind of problem. Personally I would ask around and decide the best spot and way to tie in as well as I dont know lol.