Inliners International Forums General Discussion Engines Low CFM 4 barrel carb options?

Is that maybe the purpose that this valve in the vacuum line to my distributor advance serves?



It's hooked to a thermal sensor valve that is separate from the one that controls the vacuum for the EGR and EVAP, which is only opened when warmed up. So the one on top for the timing advance may be only allowing vacuum when engine is cooler? But the round plastic piece, attached to the water neck valve, may be a check valve as well to prevent sudden vacuum lose and bog?