If I remove the PCV lines and put a breather vent on my valve cover, what negative impacts might this have? Of course I will block off the other used ports.

I keep getting oil in my intake manifold even when using 2 catch cans in series.

 

I'd think you'd get excessive crank case pressure

 

What catch can/s are you using?


Some are just crap in design.

 

First to a Mighty Mouse then to an RXSpeedworks.

 

Take one of those catch cans and put it on the clean side of the pcv (valve cover to TB).

 

You will see steam coming out of the breather and get a funky gas odor from the engine bay. Also randomly on a cold start with excessive moisture you will see a nice burp of milk shake from the oil pressure building and the moisture mixing with the oil and puking milk shake out of the line.

 

This,

 

Either that or you can just toss a breather on the clean side and keep the can hooked to the dirty side. I have mine setup like this and still have the advantages of the pcv setup and the advantages of no clean line to push oil into the intake tract.

Edit: I'm speed density though, so it may have odd effects on MAF cars.

 

He autocrosses regularly. LS motors love to pool oil in the cylinder heads under higher cornering forces. This can cause oil to be pulled through the clean side of the pcv and into the intake manifold.

 

I have a check valve in the clean side, just a few inches away from the throttle body.When I took the TB off, there is no oil in the clean side orifice. It's all coming in the dirty side.
But knowing about excess pooling certainly helps understand a bit more.

 

Instead of running the catch cans in a line, try running them parallel with a Y. The vacuum distribution across the two of them parallel may be more efficient than running them in a series. In theory they would have half the load on them as compared to being run in a series

 

I now have the catch can going between the intake and the ls6 valley cover.
I have the valve covers connected I have the ones with two ports on the passenger side. (I looked hard for these. I don't know what is engine they come on but I found a set finally) They are ported into each other on the top ports (near the window) then the bottom port on the passenger side goes to the tb.

My catch can is baffled inside and completely redone. I added a one way out only check valve with a breather on the catch can. No air can come in the breather but if too much presssure should build in the crank case at 7000 rpm I'm hoping some pressure could escape through it. Im not sure if its a good idea. The check valve does work and no air can come IN to the breather.

I also have a check valve for one way air from the intake to the catch can. What do you guys think?