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Turbo swap fuel system


cd1105

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I'm getting ready to install my 76 gas tank into my 74 260z this weekend, and i had some questions about the setup. I read on the forums that the line coming out of the tank is 8mm and a -6an line fits it is this true? I want to run steel braided lines directly from the tank to the rail and from the rail back to the return, will i have any problems with that? I have a pallnet fuel rail, with a aeromotive fpr on one end and a -6an fitting coming out of the the 1/2npt fuel rail on the other side. Is the Walbro GSL392 fuel pump a good choice to feed my fuel sysmtem? Everything is pretty much stock. I was wondering how some other people are running there fuel system on their turbo swap. I was also wondering what to do about the third line the vapor one that went to a charcol canister(which i don't have anymore).

Edited by cd1105
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8mm is -5, 10mm is -6, EFI line is 12mm, -7.

 

5/16", 3/8", 7/16"

 

-4 is as close as -6, and -8 is as close as anything on the funky EFI feed line on the tank outlet.

 

Vapor cannister is covered within the last two weeks postings.

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8mm is -5, 10mm is -6, EFI line is 12mm, -7.

 

5/16", 3/8", 7/16"

 

-4 is as close as -6, and -8 is as close as anything on the funky EFI feed line on the tank outlet.

 

Vapor cannister is covered within the last two weeks postings.

 

so the -6an line wont fit? what size line and fitting do you recommend i use for the feed and return? i all ready have a 1/2npt to -6an on both sides of my fuel rail.

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That other post was corrected just now.

As I have posted there, methinks Mr. C is mistaken. 280Z fuel tank has 15mm, 12mm, 8mm, & 6mm fittings on it for Vapor Recovery/Transfer, Fuel Pump Feed, Fuel Return, and small high point vent lines respectively. These sizes roughly convert to 5/8", 7/16", 5/16", & 1/4" fuel tubing. I can't believe nobody else noticed that.

 

The hard lines in the chassis are 5/16" (8mm) and 1/4" (6mm) for feed / return to the engine and EVAP line respectively.

 

LETS ALL BE CLEAR HE IS LOOKING FOR TANK SIZES---I think that is the confusion point.

 

The 260Z tank has the same vapor line sizes, but Feed to pump is 8mm, return is 8mm (5/16"), and the EVAP (Charcoal Cannister) line is 6mm (1/4")

 

The 240Z tank has the same vapor/EVAP line size, but feed to the pump is 8mm, and the return is 4mm (5/16" and 3/16" respectively)

 

Usually the common practice is to go oversize on flexible lines, so for an 8mm line (5/16") using a -6 line (3/8") would be acceptable as a -4 line (1/4") would hinder the flow from the hard line because it's of a smaller diameter. On fuel feed to a pump, the LAST thing you want is a restricted line, so I'd say from the tank put a -8 line, and then adapt at the pump to whatever it calls for, a -6 line would be quite a bit smaller than the current 12mm (7/16") line present.

 

And anybody who has ever tried fitting plain jane 3/8" fuel tubing over the snout of that tank orifice, or the stock Bosch EFI pump in the EFI cars knows....it's not an easy fit!

 

These line sizes have to be somewhere in some Nissan Service Manual for replacement references, I'm sure.

 

As Mr. C says, the -6 works fine on the 5/16" hard line on the chassis.

Edited by Tony D
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Not to hijack this thread, but are these sizes inside or out side measurements Tony ? ( I have no idea about tubing)

 

also what wall thickness is recommended

 

Nigel

 

note: I just realise he is not talking about the fuel line, but that is what my question is for.

post-2090-021363200 1289354390_thumb.jpg

Edited by Noddle
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Pipe is measured by I.D. Tubing is traditionally measured by o.d.

 

So the i.d. of 1/2' 035 wall will be 0.500"-(0.035"X2)=0.430" I.D.

Using thinner walled tubing would result in larger I.D.... That 035 wall is goood for like 3000#!

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