>Don't understand how a PCV
>valve works. So I am no venting my valve cover into the air using
>a crank case air filter. Is this a bad idea? The car seems to run
>much better after removing and plugging the hose going directly
>from the valve cover to the carb.
**********************
Dave,
The PVC (or positive crankcase ventilation) valve is one of those often
misunderstood "smog" related devices. It doesn't hurt performance as some
assume, and is actually quite beneficial. Ever notice that burnt oil smell
after you get out of you car? It's because you’ve vented all that hot oil
vapor out into the air. Plus if not done properly (venting to the
atmosphere should be done with a tube run down into the airstreem under the
car, and with a angled cut facing the rear to draw the fumes out) then you
stand a slight health risk from the fumes. PVC valves operate such that
when there is sufficient vacuum (any time except full throttle) the fumes
are drawn into the combustion chamber to be mixed with the fuel and burned.
On early systems this consists of merely a one way valve (PVC) and a hose
connected to the valve cover (via a flame trap inside the cover) the other
end connects to the intake manifold. In your (this) case the valve is the
constant depression carb, and the place at which the port is located, to
provide the valve action. If the car doesn't run correctly when everything
is hooked up properly, then something is not working right. In this case
you won't damage anything, but I would make sure everything is operating
the way it should. Not chastising here, but one really shouldn't
re-engineer things unless one really knows what's going on. Things can get
really screwed up that way -
Barry Schwartz in San Diego, CA
Bschwartz@encad.com
72-V6 Spitfire ( daily driver )
70 GT6+ ( when I don't drive the Spitfire )
70 Spitfire ( project )
73 Ford Courier ( parts hauler )
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