Kingtal0n

PCV is the most important system on an engine.
All engines whether performance, turbo, etc come with PCV.
All race cars use some form of PCV, without it the oil would be out of control, its not a race car.

PCV is essential in every application, because:
1. low pressure pulls light chain hydrocarbons out of engine oil
2. rapid evacuation prevents oil contamination
3. low pressure enables fully intended piston ring seal function
4. low pressure reduces windage, gobular interference, and flattens rivults (too low and it can starve wrist pins for oil as a testament to its effects)
5. low pressure prevents oil leaks and seal blow-out, helps keep oil out of seals
6. low pressure keeps oil out of the engine's oil baffles and intake


If you vent an engine to atmosphere it will cut the engine's life in half or worse. It will ensure leaking seals after 20k-50,000 miles. It will ensure a smoking low compression engine is the result of typical service. It will ensure crusty piston rings and damaged cylinder walls with increased blow by due to contamination of engine oil with unfiltered air.

It will ensure that at some point the hood will become fully splattered with engine oil and dark sludge and that you will find oil everywhere, not just the intake.

This is because: Oil spray increases with crankcase pressure, and piston ring function decreases with increasing crankcase pressure.
More crankcase pressure means more blow-by and oil spray

Lower crankcase pressure is highly desirable and somewhat easily to achieve with a little effort.
Naturally this leads to desire to control and set a specific crankcase pressure range for our engine, And that becomes PCV since pcv is the only thing that can control the crankcase pressure (its the words we chose to represent taking control of the crankcase pressure).
Desired crankcase pressure would be -0.8" to 2.5"Hg of crankcase pressure in wet sump application
-0.8"Hg is -0.4PSI the minimum for most engines recommended.
2.5"Mercury or -1.22PSI is around maximum for typical wet sump application. Too much vacuum will risk damaging the oil pump and altering oil system expectations.

The air filter paper works together with PCV for the sake of longevity and cleanliness, when the engine is modified you need to re-visit the goal of each system and deviate the power(paper OEM style air filter flow rate for a modified engine) how you see fit by adjusting the PCV valve orifice and fresh air inlet orifice diameters while keeping at least one or more paper air filters on the inlet.
We measure crankcase pressure the same way as intake pressure, using 2-bar map sensor. If you can measure intake PSI then you can measure crankcase PSI. Its a 0.5v to 4.5v style sensor for every engine in the world so very easy to detect as no voltage divider is necessary. $20 Arduino micro controller has like 15x 0-5v inputs for example. HPtuners 411 OEM ecu has EGR input, 0-5v same as wideband input. You can switch between wideband and Crankcase pressure. All stand-alones can use 0-5v inputs.
No excuses not to understand and measure crankcase pressure and setup required PCV function to get maximum life from an engine and maximum oil control fantasy


Imagine not knowing how pcv works

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https://tinyurl.com/turbo240