cardo0

Okay I bought a repalcement Evaporative Vapor Canister (EVC) from NAPA for $52. But theres no replaceable filter on the bottom and no tubing connection on bottom lid . NAPA unit just has a dual tank and purge fitting on top lid along with/next to a air tube fitting with a splash shield . Original had a separate carb and tank tube fittings on top lid while bottom lid was removable with an air fitting - covering a replaceable filter under bottom lid.
What I'm really asking here is where/what does the bottom lid fitting connect to or does it really connect to anything ? I know one of the top lid fittings on the EVC connects to the fuel tank while the other connects to a ported vacuum fitting on carb . My AIM shows nothing for the bottom tube fitting. Nothing in '74 shop manual either. :confused:

Paul Borowski

Even though that bottom "snap in" filter retainer had a "nipple" on it, no hose connects to it, at least on my '74(which is bone stock) & '75.

cardo0

Thanks for the info Paul. I thought that bottom connection would be open like that but needed to double check. I didn't want any fuel tank vent gremlins to appear while trying to break-in the cam. And I didn't trust a 30 yr old charcoal canister (EVC) either.
I'm going to try to run the stock system with the tank vented all the way through that EVC (unvented cap on tank). This new NAPA (Echlin) EVC is sealed with no replaceble bottom filter. The original replacement filter was kinda filthy but still useable. So I don't know if its a good thing that no filter changing is needed and no maintinance required. Or its now a $52 replacement item every 10 or 20 yrs. :rolleyes:
This vapor cannister plumbing may sound like a lot of time wasting BS but the EVC is another controlled leak to the carb and I need to get it right before it becomes a tuning gremlin. :troll