Question on PCV and breather on 350 TBI

[Jaydam]

So I've been researching the PCV for the past few hours, I think I'm starting to get it down but correct me if I'm wrong here.

When blowby gases go through the crankshaft and this creates positive pressure so it has to be expelled so the PCV valve opens and the fumes leave and are reburned. Now this creates a vacuum and if the vacuum remains oil will start to get sucked out of the PCV or atleast more.

So the breather hose just breathes air into the crankshaft and valve cover so the pressure is taken care of and that air is just coming from the intake.

Now I've been wondering are there any benefits to using a breather cap? or what I'd imagine a better option a breather hose going to a oil catch can and then having a filter ontop of that alongwith the connection to the intake for air to also go through there?

OH and also I've seen both PCV's and breathers have oil catch cans, and I was also wondering is the main benefit of the PCV catch just to clean up your intake manifold from oil alongside a breather one?

Correct me if I'm wrong on any of this, the whole PCV system turned out to be rather difficult to understand...

 

[90halfton]

The flow is in the opposite direction you are thinking. It travels from the crankcase to the intake, through the combustion process and out the tailpipe. There's nothing wrong with the pcv process. I'd leave it.

 

[tinfoil_hat]

Once upon a time, crank cases were simply vented to the atmosphere which was a major cause of smog. The PCV is a simple solution to case venting and like most simple solutions, you are unlikely to improve on it.
Many industrial diesel engines use catch can systems but the needs if those engines are different. They are regulated by tighter emissions and expected to run 3x as long as our GMT400 engines were.