Got a question, the PCV valve on the LS Valve cover/Block of GSR ... does it close more and more as vacuum increases to 0? Or does it open more and more as vacuum increases to 0?

 

I believe it opens with no vaccum. Thats why when you pinch the hose with the engine running it should click.

 

The PCV valve is a spring-loaded valve with a specific orifice size designed to restrict the amount of air that's siphoned from the crankcase into the intake manifold. This is necessary because air drawn through the valve from the crankcase has a leaning effect on the fuel mixture much the same as a vacuum leak. So air flow through the valve must be controlled within certain limits. At idle, air flow is reduced because little blowby is produced. When the engine is cruising and vacuum is high, airflow through the PCV valve is at a maximum to purge the blowby vapors from the crankcase.

Here is a diagram which shows how the PCV valve works.

 

Not all PCV Valves are spring loaded. The cheap ones only use a small weight.
As I have learned, not all PCVs are created equal, oil will spread across the top of your valve cover (B18B) if the PCV doesn't seat correctly.

 

Yeah, you can get PCV valves galore at most autoparts stores....
That's why you should only use Honda parts !

BSQ is just about right one with the PCV operation.

The crankcase vapors are prone to cause preignition when not metered correctly into the IM, which is why the PCV system is there. It should also be noted that if you are retaining the stock closed loop configuration, you should not put on breather filters to the valve cover as this changes the system's operating parameters. Given that the crankcase vapors are somewhat corrosive also demonstrates the importance of either keeping a full stock PCV system or go full open loop.

X2


[Modified by X2BOARD, 3:34 PM 6/28/2002]