Guest cap110680 Posted February 19, 2004 Share Posted February 19, 2004 i posted this in fuel delivery but got no replies so i thought i would try the chevy forum. i have a 74 260z and i have a 350 sbc in it. i sent my gas tank out to get boiled and sealed. i now have it back and i want to clean up all the lines as much as possible. i took out the evaporator tank on the rear passenger side, all the lines were corroded anyway. i know i will need the line to feed the carburator but other than that i am lost. do i need the evaporater tank? do i need a vent line? if so how many? also is the charcoal filter in the engine compartment neccasary? this is the only thing preventing me from firing my engine for the first time . any input would be great. thanx for your posts in advance. later, chris Quote Link to comment Share on other sites More sharing options...
baddriver Posted February 19, 2004 Share Posted February 19, 2004 I'm going to assume that you don't need to worry about emissions testing at all, since you have a 260. You need the fuel feed to the carb of course. You absolutely need a vent line, otherwise you won't be able to fill the tank. You only have to have the vent line at the very top of the tank. The other lines allow you to fill the tank and get all the air out in the event that you are not on level ground. Without them some air will remain in the tank, but you'll still be able to use most of the capacity. You can connect the large vent line up to the fitting in the fill tube (this was previously attached to your expansion tank) and this will let air out when you are filling the tank, but this leaves a couple of problems. One is fuel expansion. When gas changes temperature, it does expand, so the pressure in your tank can increase significantly. The other problem is that as fuel is pumped out of the tank, the pressure in the tank will drop, eventually leading to starvation. So somewhere you need a provision to release pressure that builds up when the fuel heats up, and to allow air into the tank to replace fuel that is pumped out. Connecting the vent line to the fill tube won't solve either of these problems because when the cap is on, the fill tube is closed to the atmosphere too. A vented cap might help, but I've never used them and I don't know if they are two-way vented or if they have a one-way valve in them. No matter how you do it, if you have removed the factory vapor canister, your car will smell like gas pretty much all the time. Restoring the factory system is the best way to address this problem. The factory system has all those hoses and vacume lines for a good reason, they are needed and the fuel tank won't do it's job as well without them. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted February 19, 2004 Share Posted February 19, 2004 This subject has come up many times, that maybe the reason nobody responded. Normally we would say do a search, but the search function is down right now, so....I for one canned the evaporator tank, and welded up all the vent lines on the tank, except the one above the sender. From there I ran a fuel hose to the spot on the fuel neck that used to attach to the evaporater tank. This is now my one and only vent hose. I drilled two small holes in the fuel cap to help the tank vent. This works very well, with no problems in filling the tank. As for the charcoal filter I canned that too, but since you live in California you may need to keep that. Quote Link to comment Share on other sites More sharing options...
Guest cap110680 Posted February 19, 2004 Share Posted February 19, 2004 baddriver, thanx for your reply. you guys here are so helpful and i would not be able to do this project without this forum. mike i like your idea it sounds simple. my only question is do you get vapors or gas smell in the car like baddriver was saying? Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted February 19, 2004 Share Posted February 19, 2004 I did the same exact thing MikeKZ said he did and have no problems at all. No odor and no fuel delivery problems. Car runs 11's on stock fuel lines Mike Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted February 20, 2004 Share Posted February 20, 2004 You can toss the charcoal filter also !!!! 2004 in CA. 1975 and back are smog exempt. 75 280Z and older..... YES ....LARRY Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted February 20, 2004 Share Posted February 20, 2004 Nope, no gas smell Quote Link to comment Share on other sites More sharing options...
baddriver Posted February 20, 2004 Share Posted February 20, 2004 I would have thought it would have a fuel odor, but if the voice of experience say's otherwise, I'd believe them. Quote Link to comment Share on other sites More sharing options...
BARACU Posted February 21, 2004 Share Posted February 21, 2004 I did the same thing that Mike did , except that I used the vent line at the rear of the tank. Works fine and NO ODORS! AL Quote Link to comment Share on other sites More sharing options...
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