Connecting stock hard lines to AN hoses

[jacob80]

Hey guys,

 

I'm at the point where I want to convert all our rubber black hoses (yuck!) to AN lines to run fuel to our surge tank, though the fuel rail, and return it to the tank. IIRC, the stock feed line is 5/16 and I'm not sure about the return. We are using the stock feed line to feed, and we are using the other line on the drive side to return. Do you guys know the sizes of these hard lines? I'm looking at these piece, which would be perfect, except for the face that (IIRC) the stock line is 5/16 and the return is even smaller.

 

http://www.jegs.com/p/JEGS/JEGS-Hard-Line-AN-Adapter-Fittings/756885/10002/-1

 

What have you guys done? Any help is appreciated, thank you!

[YellowFever]

Not sure about the fuel lines on a 240, but the 280 has 3 fuel lines: an 8mm fuel feed, an 8mm fuel return line, and a smaller vent line to the charcoal canister (all 3 of these fuel lines are on the passenger side).

 

Anyway, 8mm is .315" and 5/16 is .3125"... so the two are very close in size. Perhaps one of these fittings would work on your fuel supply: http://www.summitracing.com/search/Part-Type/AN-to-Tube-Adapter-Fittings/Fitting-Size-1/minus-6-AN/Fitting-Size-2/5-16-in/

[jacob80]

That looks to be what I need. I do know that the end of the lines are flared on the car, so how would the fitting fit over this flare? What is the small gold piece?

 

EDIT:

 

I do know my 1973 has three hard lines running to the engine bay as well; there is two that run to the passenger side and one that runs to the drive side. Right now, I am using the original feed line on the passenger side to feed to my little surge tank and the line on the driver side to return to the gas tank. I believe that the two lines I am using are both 5/16" diameter (or 7.9375 millimeters). I would like these both to be converted to -6 AN hose size in the engine bay.

Edited May 3, 2010 by jacob80

[letitsnow]

That looks to be what I need. I do know that the end of the lines are flared on the car, so how would the fitting fit over this flare? What is the small gold piece?

 

EDIT:

 

I do know my 1973 has three hard lines running to the engine bay as well; there is two that run to the passenger side and one that runs to the drive side. Right now, I am using the original feed line on the passenger side to feed to my little surge tank and the line on the driver side to return to the gas tank. I believe that the two lines I am using are both 5/16" diameter (or 7.9375 millimeters). I would like these both to be converted to -6 AN hose size in the engine bay.

 

The fitting attaches to the tube with a compression fitting, the gold(brass) piece slides over the tube and crushes down of it when you tighten the nut. You'll have to cut the flare off the stock line to get it to work.

 

To convert 5/16 to -6 (3/8, or 6/16) you'll need a -5 to -6 adapter.

 

The last time I did something like this, I used a tube nut with a sleeve and flared the stock line, it's much more of a pain.

[YellowFever]

Oooops... too slow.

 

The little gold piece is a ferrule... it slips over the hardline and is compressed by the fitting to form a seal. In order to use a compression fitting like this the flares would have to be cut off of the hardlines.

Edited May 3, 2010 by YellowFever

[Philly_G35]

I've been looking to do the same thing on my 73. The issue I am having is I can't find a fitting to work on the 1/4" return fuel line.

 

My 73 had three lines as well. The fuel supply is a 5/16" on the passenger side and the fuel return is 1/4" on the passenger side. The 1/4" line on the driver side is a vapor return line.

[jacob80]

The fitting attaches to the tube with a compression fitting, the gold(brass) piece slides over the tube and crushes down of it when you tighten the nut. You'll have to cut the flare off the stock line to get it to work.

 

To convert 5/16 to -6 (3/8, or 6/16) you'll need a -5 to -6 adapter.

 

The last time I did something like this, I used a tube nut with a sleeve and flared the stock line, it's much more of a pain.

 

I guess I'm a little confused here.

 

Looking at this item, it looks like I would but off the flared end on my stock lines and attach this, which is said to convert from a 5/16" tube to a -6 AN, I'm just a little confused about why I would need a -5 AN to -6 AN adapter. Link:

 

http://www.summitracing.com/parts/EAR-165056ERL/

 

 

Are both the line on the drive and passenger side 5/16"? If I ordered two of these adapters (http://www.summitracing.com/parts/EAR-165056ERL/), could I just cut off the ends of the two lines and install these?

 

Keep in mind, I will not be using the little puny 1/4" EVAP line.

[letitsnow]

Whoops, sorry, you won't need an adapter, I was thinking it was something else.

[Alonso*]

I did the same on my 240sx. This is my original post from ka-t.org. I Hope it helps!

 

OK I still get alotta msgs asking me how I did my fuel line setup.Maybe a write up will help reduce them

 

AN sizes can be kind of confusing at first, since all they say is -5,-8,-10, and so on.

Well they go in increments of 16th of an inch.

 

So for example, -4an = 1/4", -8an = 1/2".

I like to add 16 at the end and go from there, like this - 4/16=1/4", -6/16=3/8", -12/16=3/4"

 

The factory steel fuel lines are 8mm, or about 5/16". So -5an fittings work perfect.

 

The list below is what I used so I could run -6an braided lines,fuel rail,filter,and fittings with stock lines-

 

Earl's -5an tube nut,pair - EAR-581805ERL

 

Earl's -5an tube sleeve,pair -EAR-581905ERL

 

Earl's -6an to -5an reducer(2 req) - EAR-991907ERL

 

Summit® 37 Degree Flare Tool Set - SUM-900311

 

*NOTE-The summit flaring tool is the cheapest you'll find that can do the proper flare for AN fittings. The best one you can get that isn't super expensive and can do stainless steel tubing is made by Rigid. It goes for a little over $100 if you shop around. It is used in the aircraft industry meaning it's good enough for your 240SX.

 

*A good tubing cutter from any auto parts store. I prefer the kind that are made completely from metal,not plastic.

 

When you cut tubing make sure to deburr it,inside and out. I used a small round file for the inside and a flat one for the outside.

 

Also I like to use a little bit of oil when flaring tubing and assembling the hose ends to the braided hose.Gear oil is what I had sitting around so I used that.

 

Then slip on the -5an tube nut and sleeve BEFORE you flare it!!!

 

*Make sure you have enough room to slip the sleeve back far enough so you can put the flaring tool on.Also it has to be square to the tubing or your flare will be off and may have to redo it.

 

* The tube has to be flush with the tool or it may create problems when you tighten your fittings.

 

 

It should look kinda like this when done-(thnx ms paint!)

 

 

This is the end result after doing both feed and return

 

From here on you can run whatever fuel system components you wish.

 

 

This is what I used when I pieced my setup(with pt #s)

4 90* -6an hose ends (SUM-220687)

3 straight hose ends (SUM-220690)

1 45* hose end (SUM-220686)

6 ft SS braided -6an hose (SUM-230606)

4 -6an straight cut o-ring to -6an male (SUM-220166)***2 were supplied already with fuel rail, the other 2 are needed for the regulator***

1 External Hex Head Port Plug with O-Ring Seal, -6 AN (EAR-581406ERL)

1 System 1in-line fuel filter, -6an (SOF-200-201406)

1 Aeromotive A1000-6 Adjustable FPR (AEI-13109)

1Aeromotive Fuel Pressure Gauge (AEI-15633)

2 Earl's Performance Cushioned Hose Clamps*sold in pairs*(EAR-171032ERL)

1 AMS/Turbo240.com -6an Fuel rail

4 MSD/Delphi 75lb injectors

 

All but the injectors and fuel rail were purchased from summitracing.com

 

 

What it looks like when it comes together-

 

There you have it ppl.I feel this is a "more proper" and safer method than running compression fittings.I know other ppl have used them before,but I try to stay away from them as much as I can.

 

Any questions,post here

 

 

Good luck and have fun!

[jacob80]

I did the same on my 240sx. This is my original post from ka-t.org. I Hope it helps!

 

Awesome! So are you saying that both the 240sx and 240z both have 5/16" feed and return lines?

 

Will someone confirm that the 240z reed and return sizes are both 5/16"?

[Alonso*]

No I am not saying they are the same. Only that I did the conversion to an lines/fittings like you're planning to do.

 

Sorry I dont know what size the lines are on the Z, as I just purchased my first Z and haven't had a chance to dig my hands into it yet

[inline6]

In case someone needs this info - My 12/70 240z has 5/16" OD (might be 8mm) supply, and 3/16" OD return, and 1/4" OD vent hard line (the one on the driver's side).