PCV/valve cover question
 

I have seen several pictures of your guys' engines with new chrome Chevy valve covers on them. Did they come with the two holes in one cover and one in the other, or did they just come with one in each? All the new ones I have found in Summit, Jegs etc have only one hole in each. I gather from reading that a breather functions the same basically as the hose running from the air filter into the valve cover on the passenger side. If you only have one hole in each valve cover, on the other side is there supposed to be the PCV valve plugged into the driver's side valve cover? Sorry, I'm confused, everything I read seems to contradict each other. I have to replace my PCV valve anyway, just wanted to learn more about the system and what covers you buy. Thanks for any help.
John

The way Most "open" PCV systems work is that under high vacuum conditions such as cruise or idle the PCV blocks unburned crankcase gases from cycling into the intake charge. They instead go through a breather tube into the air cleaner assy and are introduced into the intake charge through the carburetor inlet. That is so the loss of vacuum at idle does not kill the engine or casue part throttle detonation. Under acceleration and lower vacuum conditions the PCV valve opens and allows unburned gasses to cycle through the PCV line into the manifold . The breather tube then becomes the air inlet into the crancase and the engine air filter acts as a crankcase air filter to prevent contaminated air from cycling through the motor. This whole system is set up so that crankcase gasses do not escape into the atmosphere but are instead burned. Its a simple emissions control that doesnt harm performance unless you are on the ragged edge of detonation and then PCV should be avoided as misted oil can be present in crankcase gasses and those can agravate detonation. There are other types of PCV systems that are closed and timed systems that either do not run through a breather tube and keep the crankcase in a vacuum or use engine temperature as a basis of when the PCV system is brought online. Dont worry about them. The standard open PCV system is what you are talking about and you need 3 opening. One for a breather to let in filtered fresh air, one for a PCV valve to the manifold and one to pour oil into . The one to pour oil into can be deleted if you have a slip in breather that you can pull out to add oil into the crankcase. Thats what I do on my chevrolet script chrome made in Taiwan valve cover.

I have Edelbrock chrome VC's on my engine, with 1 hole on each side. All you need are 2 holes total on the covers. I put the PCV valve on the drivers side of the motor, at the front of the VC. Then i put a chrome breather on the passenger side, at the rear of the VC. I strongly suggest that you ditch the hose going from the VC to your air cleaner, all it really does is put dirty air back into your motor. The breather should give you the ventilation that you motor needs. Here is a pic of my setup:

I use the same set up as yellow72custom. It works great for me.:D

I also have the same as yellow, except my breather is on the drivers side...up front. I just remove it to add oil.

My truck has two holes in each valve cover, so I have two oil filler holes and two for the PCV system. They are painted Chevy orange but are green-blue underneath, so they might be off another car. The hose connecting the air filter to the valve cover is not a good thing, my air cleaner fills up with oil if I don't check it enough. Anyway thanks for the input and the rundown on the whole PCV system, it helps to know how things function.