510 Fuel line question help ASAP!!

[VintageRice]

Which is the return on a 510?? Took my tank out. There's a smaller one and a bigger one. Common sense says bigger is the main. But mine looks like it used the smaller before. But previous owner might have screwed that up. Shud I switch it over to the bigger line????? Please say yes. Already put the tank back in......

[VintageRice]

 

Ok this shows the top outlet on the tank as the return line. But does not show if this is the bigger or the smaller line. Google images has nothing............ANYONE have a pic of the two fuel outlets on the bottom of the tank so I dont have to pull mine out again PWEEEEEEEEEEESE.

[Logical1]

Bigger line is the return line, I used the same reasoning you did for which is which, but alas I was wrong! I was informed that the larger return line is so that fuel doesn't have to work hard to get back to the tank.

[VintageRice]

Thank you!

 

And dangit!! Gotta pull tank back out. Cause I capped the small line and put hose on the big. Crap. I would just switch them but I bet the return goes higher in the tank or something stupid and would only pull fuel to a half tank. Gawd.......

 

 

I figured you might chime in being the Zombie Apocalypse reserve fuel tank guy. :P

[datzenmike]

It does seem weird but the larger is the return. Cooling lines for the automatic are also that way. It's to reduce/eliminate any chance of back pressure and appear to the fuel (or ATF) that there is an easy way back.

[VintageRice]

Sweet thanks.

 

Well, now its here for future searching needs. :D

[FunkyFresh520]

Where does the return line connect in the engine bay??

[wayno]

Where does the return line connect in the engine bay??

 

The 1967 Datsun 520 doesn't have a return line, and the tank doesn't have the fitting for one either.

If you have a more modern engine in your 520 with a return, then put a "T" in the vent tube in the gas fill tube, it will just drain back into the tank via vent hose, but you will still have to put a return line in back to that line from the engine compartment.

[Draker]

Where does the return line connect in the engine bay??

 

On the 510 they both come up right below the fuel filter.

[FunkyFresh520]

The 1967 Datsun 520 doesn't have a return line, and the tank doesn't have the fitting for one either.

If you have a more modern engine in your 520 with a return, then put a "T" in the vent tube in the gas fill tube, it will just drain back into the tank via vent hose, but you will still have to put a return line in back to that line from the engine compartment.

For my buddys 510.. not my 520