Hey thanks for the info. I'm going to do a layout of the system and make a Solidworks drawing. I can maybe post it so that it will be more clear.
I've seen this type of system so it is not my idea but I did not really paid attention to the details. Not enough disc space in my head. haha Sometimes streetrod stuff is not exactly correct but it works well enough for the limited amount of use we give them.
My thinking is that air will be continuously drawn in through the canister as fuel is used. When the car is shut off and simply waits for me to bring it to life again, the canister gathers fumes as required. Once the motor is started and begins to use fuel, air again comes into the canister, purging it.....hopefully.
I would think any dumping of vapors into the carb air cleaner could cause idle problems. A ported vacuum might work. My system will eventually have a blower and possibly an EFI injector so A/F ratio will be monitored. I would guess that fuel vapors dumped in will be accounted for by the o2 sensors. But I surely don't need random fuel vapors dumped in at idle, it's hard enough to keep a blown motor clean at idle. Consider also that this mess will be run on E-85. ($2.05/ gal today) I can probably tolerate some varance in mixture just as an alcohol motor can.
You know it is funny..in my younger days I would just roll the window down (hand crank not power) and say "gas fumes are just part of hot rodding, like noise, live with it." Today after 55+ years of sniffing gas and all the other hotrod fumes, I really long for a little cleaner air. haha Now if it was diesel fumes, it would be a different story. haha....yeah right a Willys with "stacks" ...I really don't wish to be banned from hotroding. haha
I'm going to the junk yard....back later.