Valve Cover Ventilation Question

[fine69]

Hello All,

On the left side, my valve cover has a hose (with a pcv) that connects to a port in the front of the carburetor. On the right, the valve cover has a hose that connects to the base of the air cleaner.

Here's my question. Should there be vacuum from the valve covers? With the air cleaner assembly removed, I put my finger over the right hand valve cover hose. I was surprised that it had vacuum that gradually increased. Is this normal? I would have thought that this hose would release rather than have vacuum since it connects to the air cleaner.

Thanks.

 

[TJay]

Yes, the PCV valve needs to have fresh air from the air breather, the PCV sends the bad gasses back into the engine to be burned. So both sides are positive air

 

[wishuwerehere82]

Sure enough. The hose connects to the air cleaner so that filtered air is pulled into the engine and fumes are burned through the carb.

 

[fine69]

Thanks for the replies.

 

[brusso]

They used to actually make a small gauge that would sit on the oil fill hole to measure this vacuum.