In classic full-blown PCV system, there is a second hose from the crankcase to
the air cleaner, with a little filter pad at the end, inside the air cleaner.
This serves two functions: If the PCV valve is sucking more than the engine
is blowing, it allows clean air into the crankcase to make up the difference.
Ideally, this is the situation most of the time. But if the engine is
blowing more than the PCV valve is sucking (like at full throttle,
or when the engine is worn out), it provides an escape path for
the excess blowby, diverting it into the engine intake instead of the
atmosphere.
Spits never had this second hose. Instead, they either suck dirty outside
air into the crankcase through various nooks and crannies, or they blow
oil out through the same nooks and crannies. :-)
My engine is in good shape, and I discovered that it sucks in air mostly
through a small hole on the bottom of the fuel pump. If I remove my
oil filler cap, I get a definite suction when I put my hand over the opening.
Doug Braun
'72 Spit
At 10:32 AM 5/9/01 , Vic Whitmore wrote:
>Ho Joe.
>
>Good question and a valid concern. At this point, I can say that in my
>"spirited" drive, I was often "pedal to the metal" but not necessarily going
>uphill at the same time. There was a small grade at one point though, and I was
>accelerating from a stop light. No traces of dip stick oil blow out though. I
>suspect that even though the vacuum drops appreciably, there is still enough to
>do the job.
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