HELP su conversion

[justin260z]

I converted my 260z to a 4 barrel, and now I want to convert it to the older round tops. The problem is I dont have the linkage connecting them together, AND I dont know what all the stuff on the carbs go to IE vacuum lines. Please help I dont even know where the fuel lines go.... Im in over my head with this one.

[e_racer1999]

the fuel lines go to the nipples on the banjo fittings.

the only vacuum lines that i have hooked up are the ones to the float bowls, the one to the brakes, the vacuum advance line, and the block vent hose thing (not the PCV, although it will be hooked up soon)

as for the linkage you can get them from Ztherapy.

[MikeW]

The lines to the float bowls are not vacuum lines but rather fuel overflow lines in case a needle gets stuck open on the inlet side. While they dump the overflow into the air cleaner they really serve no real purpose.

[justin260z]

The lines to the float bowls are not vacuum lines but rather fuel overflow lines in case a needle gets stuck open on the inlet side. While they dump the overflow into the air cleaner they really serve no real purpose.

So should I just plug those off?

[MikeW]

So should I just plug those off?

I think it would be better to run them to the air cleaner as was originally intended. If the needle valve gets stuck open the float bowls will start overflowing and can start spilling fuel directly onto the exhaust manifold. Routing it to the air cleaner will hopefully cause some of it to be sucked into the engine although some might also drip from the air cleaner onto the manifold.

[justin260z]

This is my current setup. Can I tun the su carbs with my egr blocked off?

Basically I want to bolt them onto the car & run fuel lines and be done with it, Is that possible with what I have, or do I need to go shopping?

[Bruce Palmer]

... plug those overflow nipples. Bad things will befall you...... they must vent to the atmosphere. I hink w have some photos on the ZTherapy.com website that showswhat your final lashup should look like.

What are you doing for an aircleaner??

[justin260z]

I'll probably get either those spring loaded foam thingys, or a pair of K&N's. That would be awesome if you could get those pictures, Bruce.

[=Enigma=]

Looks to me like you're gonna need some linkage depending on what's on the SUs now, as well as a fuel rail which is missing. See pics for some clues.

[justin260z]

Well Enigma, I already have the linkage that is attached to the firewall.... I just modified that to work in the 2 barrel. And I plan on making my own custom fuel lines. Thanks for the picture, it helped me out a lot.

Will the su carbs work poorly if they have no fuel return line?

[DaveN]

Re float bowl vent lines --

Their main purpose is to keep the pressure over the gas in the float bowl exactly equal to the pressure around the carburetor inlet. Any mismatch changes fuel flow, so those tubes have to be vented to the inside of the air filter.

[=Enigma=]

Well Enigma, I already have the linkage that is attached to the firewall.... I just modified that to work in the 2 barrel. And I plan on making my own custom fuel lines. Thanks for the picture, it helped me out a lot.

I was referring to the linkage that connects the linkage you have(firewall to manifold), to the linkage between the carbs.