Hi all,

 

Okay, final conundrum on the 600zx is down to the fuel tank breathing.

 

I have no return on the regulator so just one pipe from the gravity fed connector on the base of the tank going to pump, then the filter then the regulator then onto the carb.

 

Now i know on the standard zed you have a charcoal canister which collects the petrol vapours but as that's been bypassed and missing now i just have all the pipes on the top of the tank left and a return pipe coming up the front of the tank.

 

Now i know i need to pull in air as the vacuum increases in the tank and i can do that via a PCV valve i have lying around that would fit inline perfectly on one of the pipes going to the old fuel pump in the tank.

 

The question is i also need to vent excess pressure from the petrol vapours on a hot day/car getting hot.

 

So do i need a one way valve at all and should i just have one pipe running higher than the top of the tank out to the wheel well to vent to atmosphere?

 

Any ideas guys? As i want to get the car off to its MOT on Thursday and if anyone is in the know it'd be appreciated to hear their opinions :)

this really is an opinion, so best wait untill some experts come along, but i reckon just a pipe going from the tank to the outside (as long as its higher than the tank of course) should be fine, maybe a filter on the end of it rather than another valve?

 

like i said though, get an experts opinion

That's what i was thinking, i have a spare mini plastic fuel filter that would ideal for the job and sit under the wheel arch with no problems so i'll wait and see what the pro's say but i agree with you that should be enough for 1960s engineering :)