[Healeys] crank case ventilation

[Bob Spidell]

Wouldn't an 'inlet upstream of the throttle plate' supply fresh, 
filtered air?   Something like this:

http://beesandgoats.com/boostfaq/stock_pcv.jpg


bs


Richard Ewald wrote:
> Actually modern cars do have completely sealed systems with no fresh 
> air introduced into the system.
> On the cars I service there may or may not be a valve, but in either 
> case there are two hoses from the crankcase.  A small hose going to 
> manifold vacuum, and a larger hose going to the inlet upstream of the 
> throttle plate.
> the dipstick has an o-ring to seal it, and the oil cap is sealed.
> At idle, the small vac hose pulls a small vacuum in the crankcase.  
> Not enough vacuum is pulled to draw air in past the crank/cam seals. 
> At high load, the blow by is sucked out the large hose.
> Simple and works great.  How it would adapt to a LBC I am not sure.
> Rick
>
> On Wed, Mar 17, 2010 at 2:00 PM, Bob Spidell <bspidell at comcast.net 
> <mailto:bspidell at comcast.net>> wrote:
>
>     Hi Michael,
>
>     If you mean the non-vented approach pulls more vacuum on the
>     crankcase I agree. But, you're pulling unfiltered air in through
>     other gaps (like around the crankcase seal).
>
>     The 'sealed' PCV system works good on our cars, but it's not a PCV
>     'system' per se. A proper PCV system circulates filtered air
>     through the crankcase, mixes it with blowby and sends it back
>     through the intake manifold.
>
>
>     bs
>
>     --------------------------------
>
>


-- 
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Bob Spidell           San Jose, CA            bspidell at comcast.net

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