PCV removal

[LEMHEAD16]

What would happen if you totally deleted the system and just ran a breather off of the valve cover?

[lilskyline240]

not much...other than u might have a slight dip in your rpm while coming to a stop becaues unmetered air is goin through the motor....but thats bout it

[KATwo40]

not much...other than u might have a slight dip in your rpm while coming to a stop becaues unmetered air is goin through the motor....but thats bout it

Please explain, as I don't see how the crankcase ventilation has anything at all to do with air entering the combustion chamber.

[LEMHEAD16]

It doesn't!

[lilskyline240]

actually it does....cuz that air does go into your motor...it goes into the crankcase, but it does go into your motor....on my 300zx i had a idle problem coming to lights the rpms would drop by like 200 rpm then stablize....it was because i ran a breather on my PCV valve....if the air doesnt matter if it is metered or not, nissan wouldnt have routed it to the intake, they would have put a filter on it

[nissanfanatic]

The only way unmetered air could enter your engine via removing PCV was if you didn't plug the hose running from your PCV nipple to the intake manifold..

My setup is:

Hose running from PCV nipple to pointed towards the ground on the passenger side of my engine bay. Hose running from the valvecover breather to pointed towards the ground on the passenger side of my engine bay.

[LEMHEAD16]

The only way unmetered air could enter your engine via removing PCV was if you didn't plug the hose running from your PCV nipple to the intake manifold..

My setup is:

Hose running from PCV nipple to pointed towards the ground on the passenger side of my engine bay. Hose running from the valvecover breather to pointed towards the ground on the passenger side of my engine bay.

So you just run a hose from the black box on the block out underneath the car? and one from the valve cover. Taht is what i want to d but, I want to make sure the car will still run!

[KATwo40]

Nissanfanatic:

What is the benefit of this modification, please? Lookin' for pros/cons, as I'm nearing the completion of a fully forged setup and I'm interested in this PCV deletion.

[nissanfanatic]

What box..???

There is just a hex-to-nipple fitting(brass) check valve that screws into the front timing cover. Stock, that nipple is connected to the intake manifold. When idling stock, vacuum from the intake manifold will draw fresh air through the valvecover breather that is metered to get all of the blowby out. Under boost, obviously it closes, bla bla bla...

I changed it so that the valve wasn't being held closed under boost. I guess it works fine...

Benefits... cleaner oil..