Hey guys, I had a question that maybe some of you can help me out with. how important is the PCV valve? Do I need it? I ask this because I want to get a pair of valve covers that dont have a opening for a PCV valve.

 

PCV, positive crankcase ventilation, is critical, especially at higher RPMs to help release crank case pressure built up by the combustion process. Piston rings do not seal 100%. At the time of ignition, some of that expanding gases squeak by into the crank case causing pressure, referred to as blowby. If you don't use a PCV that pressure will eventually release somewhere such as a blown gasket; oil pan, intake, etc. Most valve covers have a location to drill for a PCV adapter. Here is a quick search on web. http://www.aa1car.com/library/pcv.htm , to better help you understand.

 

In addition to releasing pressure, PCV valves also remove corrosive exhaust gases from the crankcase. Without a PCV valve, the crankcase tends to accumulate a layer of slightly corrosive crap all over the place. Not great for engine longevity.

There is no downside to running a PCV system, until you get into severe high performance situations where there is no engine vacuum to run the PCV valve.