Hose route for the gas tank vapor container

[burdar]

72, 73 and 74 used the charcoal canister.  Every year has them hooked up a little differently I think.  In 73, all three nipples are used.  The center one is from the tank vent.  The others both go to the carb.  One goes to the bowl vent...the other goes to the front vacuum fitting on the carb.


In 74, the carb changed and there is no bowl vent.  The line closest to the inner fender is plugged off.  Obviously, 2 and 4 barrel carbs are different as well.

[Chlngrcrzy]

So it vacumns through the bottom of the canister, right? My carb has no bowl vents.

[burdar]

The tank vent is exposed to the canister.  The charcoal is supposed to keep any vapors trapped inside.  When you start the engine, the vapors are drawn into the engine.  Yes, there would be air flow into the canister from the bottom when there is a vacuum in the tank or when the engine is running.

[Chlngrcrzy]

On the top of my canister, the 3 lines are titled as such; Purge, Carb, Tank vent.   I found that i do have a spot on the front of my Holley to run a hose to the canister, and obviously the tank vent goes back to the vapor separator by the tank, but i am not sure where the purge line goes. Any ideas or pictures?

[burdar]

 The purge line goes to the carb. It should go to ported vacuum. The nipple marked "carb" would go to the bowl vent if your carb has one.

PCV valve goes to manifold vacuum on carb(nipple below throttle blades) The purge line goes to "ported" vacuum.(nipple above throttle blades)

[Chlngrcrzy]

Ok, yeah my PCV is attached to the rear of the carb. So i guess i don't have a bowl vent on my carb after all. Not sure why i even have this canister, if all i have is my gas tank venting to it.

[burdar]

It will keep your garage from smelling like gas. Not that I'm an environmentalist but why dump that stuff into the air if you don't have to.