? about PCV valve and valve cover breathers

[jcode68]

I am currently using a PCV valve plumbed from the passenger side valver cover to the PCV port on my Holley carb. Additionally, I have an oil fill cover on the driver side valve cover that has a hose attachment running to the base of the air cleaner. I must admit, I don't really know squat about crankcase ventilation and engine vacuum, but am starting to woder if my setup is correct? Should I just run a normal oil cover on the driver side cover with no air provision? I believe the piece I have came with the valve covers when I purchased them, so I just assumed I should use it. The reason I ask is I have some hesitation on take off and am in the process of tracking down wether this is a vacuum leak, a mal adjusted carb, bad timing ro all of the above.

 

[180 Out]

Whatever the cause of your bog, it's not the connection between the oil breather and the air cleaner. What you have is called a "closed system." The oil breather merely vents the crankcase. It's the source of intake air when the pcv valve is sucking from the other side. When the pcv isn't sucking -- e.g., on engine shutdown or under WOT -- the blowby gasses that normally go through the pcv vent through the breather. In a closed system, they go to the clean-air side of the air cleaner and into the carb venturis. In an open system, they go into the atmosphere and combine with N20 and NO2 and ultraviolet radiation and make 03, aka ozone, aka smog.

 

[TBP]

Yay smog.

 

[mustangdave]

I agree. the pcv is not your problem. You have it hooked up properly.

 

[jcode68]

Thanks for the info and confirmation that I have it hooked up properly. I suspect my problem is carb related. I'm still running my 600 cfm Holley on my 347. I plan to pick up a new 670 cfm Street Avenger, which is supposed to be the best size for my config. I also need to spend some time to verify I don't have a vacuum leak. It's never ending!

 

[boatillo]

I had the same setup, pcv to the back of holley carb from passenger side, and another running from drivers side into the bottom of air cleaner.

However, recently bought and installed some nice aftermarket covers that didn't have the provision for me to use the same setup really. Pcv valve to carb is the same, but drivers side had a different baffle and long neck coming out of the cover -- ie old push-in breather with tube running to air cleaner wouldn't fit anymore. I just bought a chrome push-in oil cap that fits, and plugged the hole in bottom of air cleaner.

Is this ok to do? Should I find some breather cap that fits the driver side cover and run it to the air cleaner again, or stick with the cap?