All carbs have bowl-venting to atmosphere.
they have to, else the fuel will not flow thru the jets.
Sometimes the vent is just disguised a lil, and ends up in the airhorn.
Here are some ideas;
If you don't collect the fumes from the carb, it kindof defeats the whole thing cuz that's where most of the fumes will originate from, as soon as you shut the hot engine off.
If obtain a 3-port canister, (collect/purge/and signal) you have to run the signal port to something/anything, else the tank fumes will dead-end in the canister, and will never be purged.
If you run a 2-port canister (collect and purge), then the fumes will be continuously routed to whatever port you connect the purge line to. With the engine turned off, the fumes will enter into the carb, and rise up out of the carb and into the the filter house and then up into the atmosphere, cuz they are lighter than air. So it kindof defeats the whole thing.
To run this canister, there will have to be some sort of check-valve in the purge line, to prevent continuous venting with the engine off.
More ideas;
>You can signal your canister with the spark-port, but you will need to ensure that the purge line does not suck air, else the V-can won't work.
>I have never seen it done but I suppose you can route your purge line to the PCV circuit, but I highly recommend a control valve, to prevent continuous purging. In this case, you probably don't want it to be working at Idle. This would probably work well being signaled from the spark-port.
If the canister continuously purges with the engine off, I suppose the tank could fill the crankcase with flammable fumes, which could be dangerous.
>If your Vcan get lazy, because of the long signal line, you can install a vacuum amplifier. This gizmo looks like a 4inch or so black plastic sphere. You mount it on the Passenger valve cover between the Vcan and the sparkport. It has 3 ports. One is for manifold vacuum, another would go to the canister, and the third to the Vcan circuit. How it would work like is; the canister gets connected to the intake manifold whenever the carb calls for vacuum advance. Because the signal line from the Vcan circuit to the amp, is so short and small, it will not affect the vacuum advance in any meaningful way.
>You can get such an amp off any smog-era slanty car. Don't confuse it with the similar sphere that works the cruise. That one only has one port.
OOps I spotted an error; I'll have to fix it, BRB.
Ok all better now
