The standard PCV valve setup used on most cars in the last decade or two
has a line from the crankcase going to a PCV valve and then right to the
manifold. The PCV valve regulates gas flow from the crankcase to
the manifold, and is supposed to allow MORE flow when
the manifold vacuum is slow (e,g. when your foot is on the gas),
and LESS flow during idle (when it would upset the mixture).
There is also supposed to be a second vent to the crankcase that
usually lets fresh air in when the PCV valve is sucking more than
necessary, and sometimes lets excess blowby out when the PCV valve's
flow rate is not high enough (e.g. a worn out engine).
This arrangement does NOT depend on the carb, and you could certainly
install it on a Weber-equipped car, using whatever PCV valve is speced for
other cars with small engines. The older Spits with the big flat round PCV
valve
on the manifold worked like this. I have that setup on my car, and it works
fine.
At idle, I have SUCTION at my dipstick hole, and no signs of "blow" on
the outside of my engine or my driveway. (And this is a 9:1 engine).
In any case, the flame war is amusing, but why can't we argue about MY problems?
Doug Braun
'72 Spit
At 11:20 PM 3/30/01 , Vic Whitmore wrote:
>Since there doesn't seem to be a way to increase the vacuum on the DGV, and my
>examination of same shows that there is no place where one ever existed (in
>some
>other application), the catch can is a good solution, vented directly to the
>crankcase, and the valve cover, with a tube to the air filter connection to
>catch the vapors.
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