8/12/01
Jim et al,
The system you describe here is exactly the way it has been done
since the beginning. The only major change since 1961 or so, when these
systems first came into use, is that air ENTERING the crankcase now usually
comes from the carburetor air filter--only clean air this way. Also vapors
which may be released from the crankcase while the engine is stopped, but
warm, are trapped inside the air filter housing instead of entering the
atmosphere through the vented oil filler cap. They are sucked in through
the carburetor when the engine is restarted. The original system was
called Positive Crankcase Ventilation (PCV). The current system is called
Closed Crankcase Ventilation (CCV). Prior to either of these, there was
usually an open tube directed downward to vent crankcase fumes directly to
the air. Intake manifold vacuum was not used to suck the vapors out.
Sometimes the bottom end of the tube was cut off at an angle which was
supposed to cause some suction when the car was moving (venturi effect).
These were called road draft tubes.
Regards,
David Kernberger
--------------------------------------------------
Pete,
I am also running a Holley 390 on one of my Buick 215s. I have a PCV VALVE
in one rocker cover that plumbs into the 3/8" connector hole in the Holley
base.
The other rocker cover has a vented oil filler cap. So the air comes in the
vented oil filler cap and flows around in the engine and out through the
PCV VALVE. It seems to work OK. This particular engine has been in
continuous service since 1962. Although the Holley was not installed until
1977. The Holley has not had a kit or cleaning since it was installed in
1977. It seems to be running fine. I have replaced the PCV every 10 years,
just as a
preventive measure.
Regards,
Jim B.
>----- Original Message -----
>From: "Pete Bronlund" <peteb@clear.net.nz>
>To: <buick-rover-v8@autox.team.net>
>Sent: Saturday, August 11, 2001 5:18 PM
>Subject: Best approach to add breather system...?
>
>
>> Hi there folks. I know that i must remove the blow-by gases from the
>> crankcase of my reco'd Rover 3.5liter (or suffer chance of expensive
>damage
>> in a backfire) but since i'm using a 390 Holley what arrangement should i
>> plumb in? Although in my country the emission regulations aren't all that
>> strict yet, shouldn't there be a PCV valve included?
>>
>> On the original Rover & SU carbs there were some 'tank' things that had
>mesh
>> wire in them & were called flame traps plumbed between each rockercover &
>> each carb. Now i have a single 3/8" connect on the Holley base & a connect
>> on each rockercover.
>>
>> Any ideas or approaches to this wee problem appreciated.
>>
>> Regards Pete.
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