PCV and oil breather cap on same valve cover

[old cool]

I have read that oil breathers and PCVs should not be put on the same valve cover. This was particularly true on the V8. I have not found any information regarding inline 6's. In mid sixties I see pictures with and without oil cap breathers. What is correct? I have read where oil can get back into your intake when breathing apparatus is incorrect.

[PGSigns]

On a 6 you have to put them in the same valve cover. Most pcv issues start with using valve covers with out the baffles in them and pulling oil through them. The factory covers are baffled well.
Jimmy

[66Submarine]

X2. Early ones use a vented breather/oil fill cap for the PCV to pull air from, and later ones (or ones that came with emissions, I guess) use a non-vented cap and have a hose running from the side of the valve cover up to the air cleaner to pull filtered air.

[old cool]

thanks for quick reply. By baffles are you referring to the plates within the valve cover?how does one verify a pcv is working properly? If it looks right does that mean it is right.

[1963c-10]

Originally Posted by old cool

thanks for quick reply. By baffles are you referring to the plates within the valve cover?how does one verify a pcv is working properly? If it looks right does that mean it is right.

Pull the pcv valve while the engine is running.....you should feel vacuum pulling on the bottom of it.

[old cool]

Very strong suction as I recall. Engine got rough too. My question also had to do with right pcv. Mine is not made by gm or USA. it looks like a generic off an orielly's wall.