fitting fuel press gauge to a 3400 rail help

[americasfuture2k]

i need help fitting a fuel pressure gauge on the schrader valve fitting. i took the schrader valve cap off and went to many hardware stores to see if i could make a 90* or 45* bend to fit my fuel pressure gauge on permanently. or semi permanently. no luck. but i did find out that it is 7/16-20 . but nothing i find online converts that to a known size of NPT or AN. so what size of 90* or 45* fittings do i need to semi permanently fit a fuel pressure gauge to the fuel rail? and later fit a "T" fitting on so i can also add a pressure sensor for a remote fuel pressure gauge shortly?

[asylummotorsports]

You need an NPT to AN fitting. 7/16 to #8 AN. (although AN 6 is probably large enough.)

Think of AN numbers as a division of 32. (Corrected! It's 16 not 32)

4 = 1/4"

6 = 3/8"

8 = 1/2"



get it?

ANY industrial fluid/hose supplier can give you one, or go Jegs or Summit on-line and look at Russel or Earls.

But locally will be alot cheaper.

[americasfuture2k]

just got off the phone with summit. they said that AN goes in divisions on 16. but they didint have any luck.

im trying to fit this gauge to the fuel rail pointing 90* up.

http://www.summitracing.com/parts/RUS-650340/

[sprucegagt]

It's actually a AN-4 fitting. I used the following items for my setup. The gauge sits right beside the power steering pump resovoir(sp).

http://www.summitracing.com/parts/RUS-670290/ Fitting
http://www.summitracing.com/parts/SUM-800299/ Gauge

[americasfuture2k]

do you have any pics of your setup?

[sprucegagt]

I do, but they are at home. I'll post them up tonight.

[americasfuture2k]

rock on. ill be choosing a different gauge than the one you have listed. but same fitting. thanks for your help.

[sprucegagt]

They are overall engine pics, but they do show how the FP gauge fits.

[americasfuture2k]

on the inside of that adapter on the npt female fitting, its slightly beveled. is the male npt fitting on your gauge beveled? mine isnt. and it was leaking with steady drips. tried tightening the gauge by hand screwing it on by the gauge itself. well i broke it. i dont know my own strength.
did yours leak any? and where did you get that endcap? im just using the 3400 rails cap.

[CNCguy]

NPT threads are tapered and wedge together as you tighten them. Minor differences between internal and external threads leave small voids that leak. You need to put a thread sealer or Teflon tape on the threads, before assembly, to fill the voids and create a positive seal.

When tightening a gauge always use a wrench on the hex area of the fitting to avoid putting strain on the gauge.

[3400-95-Modified]

I just used 37* tube fittings from my local hardware store... WAY cheaper than AN stuff online.

I have a T at my schrader valve, then a -4an line going to the fuel solenoid for my nitrous, and the second port going to another -4an line that goes to a brass 37* tube to 1/8NPT fitting, and then my electric sender to my gauge in the car.

I feel that a gauge under the hood does you no good unless you’re running it on a dyno... How can you tell what the pressure is at WOT under load that way

[sprucegagt]

I feel that a gauge under the hood does you no good unless you’re running it on a dyno... How can you tell what the pressure is at WOT under load that way

I agree, the gauge I put in is mainly for looks.

[americasfuture2k]

what thread sealer is safe for fuel systems? i was curious about that and not sure what was safe to use. i think i have some teflon. is that safe to use with fuel?

yea, i learned that the hard way. D'oh. oh well, just out 20 bux. thank god thats all.

mine is for determining fuel system problems. ive had bad luck with fuel systems lately and this is just for added measure. and it was cheap.

im going to get a DEFI stand alone fuel pressure gauge along with some other ones.

I just used 37* tube fittings from my local hardware store... WAY cheaper than AN stuff online.

I have a T at my schrader valve, then a -4an line going to the fuel solenoid for my nitrous, and the second port going to another -4an line that goes to a brass 37* tube to 1/8NPT fitting, and then my electric sender to my gauge in the car.

I feel that a gauge under the hood does you no good unless you’re running it on a dyno... How can you tell what the pressure is at WOT under load that way

do you have a pic? and what size T? i couldnt find one at ace, or lowes. i didnt bother with home depot cause i dont need a pack of them. just one.

[IsaacHayes]

Teflon will hold up, but just don't let it get in the fuel lines/rail. Easy way to clog an injector, or carb....

Is there a Permetex for fuel line use? I'm sure there is.

[3400-95-Modified]

do you have a pic? and what size T? i couldnt find one at ace, or lowes. i didnt bother with home depot cause i dont need a pack of them. just one.

Same size as my other fittings, its a 37* 1/4 pipe swivel T, I got mine from Napa IIRC.

This pic is when I had the other output capped.. its now connected to another line running to my electronic fuel pressure gauge.