Oil Separator/ Catch Can

[Tony1968]

No I never heard that before.
Why would you want the oil to go back to the valve covers ??
The idea of a catch can is to catch the oil,then you drain it out of the catch can if it gets too full.
Guy

Because the oil will pool in the line and will be excessive if not allowed to drain back. The can will still do its job only better because it will more easily remove the vapor and allow it to condense into the bottom of the can.

 

[pontiacgp]

This is starting to sound like a Red Green episode......

 

[GuysMonteSS]

Because the oil will pool in the line and will be excessive if not allowed to drain back. The can will still do its job only better because it will more easily remove the vapor and allow it to condense into the bottom of the can.

I think that the vacuum will pull the dirty oil/vapor into the catch can,and not collect in the line.
The oil being extracted by the PCV valve is not clean oil.It's more of a contaminated by-product of blow by exhaust gas,which every engine produces,some may be producing more than others.
I dont know about you,but I dont want that dirty oil going back into my engine.
Then,with a air oil seperator/catch can plumbed in between the PCV and the vacuum source,the dirty oil/vapor collects in the catch can until it can be drained out,thus keeping it from being recycled back into the combustion process.
This is assuming that you have a baffle or strainer where the PCV valve goes into the valve cover to prevent engine oil being sucked out.
At least,this is my take on how this should all work.
Guy

 

[565bbchevy]

On my BBC I have a vacuum pump and a catch can with a breather and what my pump pulls out of the engine is basically a mist and will have moisture mixed in so I would not want it back in my engine since it is contaminated oil and I am fine with just draining it periodically IMO

 

[Pronto-]

That oil vapor has moisture in it that will in turn contaminate the oil that collects in the can. You do not want that going back into the engine. Bad mojo.

 

[Tony1968]

I agree with all stated. My point is I don't want oil sucked into the can. The vapor/mist is going to be put in the can.
If you have a droop in the line feeding the can oil will accumulate and vapor can and will pull oil into the mix. I just want the bad stuff out. But hey what do I know 🤔 I have stock valve covers with baffles but actual oil is known to get by

 

[lilbowtie]

I run with a breather on each valve cover and never had any oil problem.

 

[565bbchevy]

I run with a breather on each valve cover and never had any oil problem.

For me having the big cubes and high rpm shifts having control over how much crankcase pressure I have works well for my set up since I would rather pull than push the pressure out.

 

[BuickBroke$]

I run with a breather on each valve cover and never had any oil problem.

My problem with the breather set up I have right now is that oil comes out and drips on the header.

 

[lilbowtie]

My problem with the breather set up I have right now is that oil comes out and drips on the header.

I was worried about higher cc pressures being a race engine and seeing nothing but high RPMS but the simple open PVC has worked for me.