When to ditch the PCV system?

[bmo37]

Never really thought about it but what would be a good threshold to switch over to a catch can evac setup versus the stock pcv system. Is it applicable with low boost setups 7lbs or less, does it apply for larger cubes or just higher spinning motors? I know in my case I'm looking to go this route simply because I'm adding more boost with a pulley upgrade.

 

[RacEoHolic330]

Subscribing. This seems to be the only topic where I cannot find a true definitive answer even after searching and bookmarking many different threads from numerous performance sites. Many people seem to have success with running a -12an line from each valve cover into a vented catch can while deleting the PCV. Others have ran the lines and have kept the PCV (supra/TC type). Some have use check valves as well.

Then there are those that used an evac pump. I understand that there are regulators involved to create the right amount of vacuum inside the crankcase, but what is considered the proper amount of vacuum? Do you adjust until you start pulling oil out of the crankcase and then back off? So many possibilities.

This topic makes my head hurt.

 

[bmo37]

Yeah I'm in the same boat I researched this topic alot and there are handfulls of different methods but all of them are usually generalized in the sense they work or do to some extent but with side effects. I read of people running -10, or -12 weld bungs with stainless hose to a breather catch can while plugging the pcv on the intake. Others run a dual pcv out each valve cover, some do the vacuum pump, others go breathers out the valve covers but leak oil.

 

[RacEoHolic330]

Anyone else have thoughts?

 

[vristang]

The more ventilation the better, until you start pulling oil out of the crankcase of course...

The stock pcv system is for emissions, not performance.

 

[RacEoHolic330]

I'm considering the -an lines on the valve covers as well as welding a bung on the lower intake for a 3rd -12 line to the vented catch can. Some people on theturboforums have mentioned doing that setup, but I have not heard back from anyone as to whether or not it has been successful. I assume if people have had success with only the valve cover lines, than a 3rd line from the lower cannot hurt.

I'm trying to find a successful method without the use of an evac pump. To me, another pump is just something else that can potentially fail.