Yup Another PCV Discussion

[Moparfiend]

So I have read threads here and other sites regarding the value of the PCV system BUT I am not convinced or don’t fully understand the value for me in my application.

Caveat, the environmental factors are not a consideration here.

It seems the main value proposition of the PCV is that it aids in the evaluation of corrosive gases via positive pressure.

However I am NOT running a factory air cleaner. So it’s a partially open system vs the factory closed system via pulling from the air cleaner.

Questions:
1. Does this partial open system have any negative effects?
2. How effective really is the PCV compared to just duel passive valve cover venting?
This I know is a can of worms but implementing it for my application requires some mods that I am not thrilled in performing. Therefore I am contemplating possibly NOT implementing it.

 

[toolmanmike]

The early systems were open. A breather/oil fill cap on one valve cover and a pcv on the other.

 

[pnora]

There really is no good reason not to run one.

 

[Kern Dog]

I run a breather on the right and a PCV on the left. This means the right side provides some air flow going IN, the left side pulls it through the crankcase. The vacuum of the PCV does help the rings seal better too from what I gather.

 

[Moparfiend]

There really is no good reason not to run one.

What about gumming up the valves with the crap that you’re trying to expel from the crank case?

 

[Moparfiend]

I run a breather on the right and a PCV on the left. This means the right side provides some air flow going IN, the left side pulls it through the crankcase. The vacuum of the PCV does help the rings seal better too from what I gather.

Wondering how that can help. The pressure differential between the crankcase and the cylinder is huge….

 

[eldubb440]

What about gumming up the valves with the crap that you’re trying to expel from the crank case?

that's not a good reason lmao...... he used a double negative..... pretty sure he supports running a PCV

 

[eldubb440]

I noticed the cars that have a rubber hose from the breather cap to the air breather is kinda bogus....... it doesn't suck "filtered" air as the nipple is outside of the filter element....... so whats the purpose of the hose other than keeping the valve cover clean and trashing the air filter when blow by is present?

 

[Moparfiend]

that's not a good reason lmao...... he used a double negative..... pretty sure he supports running a PCV

I am referring to this… Contaminated air being drawn from the crankcase into the intake.
Why evacuate contaminants from the crankcase then shove them into the intake whats the benefit other than re-burning for better emissions (which I put a caveat for up front).

 

[toolmanmike]

I am referring to this… Contaminated air being drawn from the crankcase into the intake.
Why evacuate contaminants from the crankcase then shove them into the intake whats the benefit?

Polution control. The downdraft tube was first, pcv second, pcv with breather from air cleaner next

 

[Moparfiend]

Polution control. The downdraft tube was first, pcv second, pcv with breather from air cleaner next

So are you saying here that this system is only for environmental purposes?

 

[turbine68rt]

Why evacuate contaminants from the crankcase

Unless you want that mixing with your oil.

 

[toolmanmike]

So are you saying here that this system is only for environmental purposes?

Yes

 

[Kern Dog]

So are you saying here that this system is only for environmental purposes?

Not entirely.
Some racers put one way check valves in their header collectors and plumb it to the crankcase. This pulls vapors and pulls the rings out to seal the cylinders better. It helps both conditions.

 

[lewtot184]

A byproduct of combustion is water. The pcv helps control this in the crankcase.

 

[toolmanmike]

Not entirely.
Some racers put one way check valves in their header collectors and plumb it to the crankcase. This pulls vapors and pulls the rings out to seal the cylinders better. It helps both conditions.

Vac-u-pan

 

[Moparfiend]

Unless you want that mixing with your oil.

You did not take my comment into context mate. In fact you only took part of my sentence.
What I actually said was:

“Why evacuate contaminants from the crankcase then shove them into the intake”

If it helps to positively draw moisture and contamination out of the crankcase and this is why you do it then it seems TO ME ANYWAY that I would use a vacuum pump and then not put it back in the engine.

 

[pnora]

Why did you even post this question. You obviously have your mind made up. No sense beating people up because it does not follow your narrative. I remember why you are against this. So do it your way and you can inhale the fumes and wipe the motor off every time you drive it.

 

[Kern Dog]

Wondering how that can help. The pressure differential between the crankcase and the cylinder is huge….

The PCV system pulls vacuum from where the oil is…. In the areas like the lifter valley and below the pistons. It is sucking out vapors that build up when combustion gets past the rings. The flow goes from crankcase area, through the PCV valve, through the hose and then into the intake and combustion chambers. With a worn out engine, it will accelerate oil usage since it is pulling polluted vapors in the crankcase and pushing them in to burn, diluting the air/fuel mixture even more. Oil going into the combustion chambers fouls plugs faster.

 

[Moparfiend]

Why did you even post this question. You obviously have your mind made up. No sense beating people up because it does not follow your narrative. I remember why you are against this. So do it your way and you can inhale the fumes and wipe the motor off every time you drive it.

I am not sure why you believe I have my mind made up nor why you think I am beating anyone up. We are having a respectful conversation and I am trying to better understand this system. I’ve been and will continue to be respectful here. Just was clarifying what I was saying.