[Kingtal0n]

Originally Posted by PoorMans180SX

Have you seriously never pulled the intake manifold off an engine and seen and felt the oil varnish in it? ....

....
If it?s connected to the intake manifold (how most engines are configured), the PCV valve is closed under boost mate.

If the pcv valve is shut during BOOST mate, then HOW can oil possible get into the intake manifold from there during boost? Can you not see that its impossible for oil to take that route... there is no way to oil down an intake during boost because the pcv valve IS shut.

So where do you think the oil is coming from? I will discuss at length below

It also may or may not be connected to the air intake of the turbocharger (which would be a pretty poor way to do it btw). On an SR20 it definitely is not.

All sr20det engines and ALL turbocharged engines from ALL factories from ALL manufacturers ARE DEFINITELY connected this way, that is Air Intake Pipe of turbocharger -> Crankcase.

ALL of them. So what are you trying to say? Have you never seen a stock turbo engine before? This must be a typo, I do not think you mean what you say

That?s because there is vacuum in the intake manifold at cruising, where the pcv is doing most of it?s work. You don?t need a pcv when connected to the intake of the turbocharger because there?s no way it sees positive pressure there.

Sorry, "where the pcv is doing most of it's work" you have it backwards. During idle/cruise there is very little blow by, so by definition the pcv is doing the LEAST work. During BOOST is when blow-by is maximum, therefore pcv will be doing the MOST work during BOOST when the system is configured properly.

The clean air feed I?m talking about is when cruising, where the air is pulled through the air filter, down into the crankcase, out the pcv valve and into the intake manifold. That is ?positive crankcase ventilation?

That is HALF of the crankcase ventilation system. And it only counts as PCV if the pressure is below atmospheric between 0.5 to 1.5psi negative pressure. It is possible to have a massive flow of crankcase air without any negative pressure because PRESSURE and FLOW are two different things. This is where majority of people get lost. If you increase the orifice diameter and air filter flow rate you also increase PCV *FLOW RATE* to the intake manifold while simultaneously INCREASING the crankcase pressure (decreasing the effect of PCV), BOTH of which will INCREASE OIL ASPIRATION!! In other words, the two are inversely proportional at this end of the system: Increasing flow rate will increase crankcase pressure!
That is the NEGLIGIBLE portion of the pcv system. This is what you are confused about and I'm trying to fix it for you.
The intake manifold suction is MINIMAL. It is literally the smallest and most insignificant portion of the pcv system since blow-by gasses and crankcase pressure is MINIMUM during that situation.
Oil aspiration during through the pcv valve during that period is due to mis-configured system, poor understanding of the difference between flow rate and pressure. Since the engine- whether a 2000hp or 200hp engine is at idle or cruise- both will produce a very very small mass of blow-by gasses compared with WOT gasses which is considered NEGLIGIBLE during operation, i.e. 2000hp engine needs 10hp to cruise, a 200hp engine need 10hp to cruise: it is the same power output so oil aspiration (if any) will be the same (negligible) when the system is configured properly.

. Under boost in this configuration, the PCV valve is closed, which is where your turbo intake comes in, helping to evacuate the crankcase when the PCV valve is shut. Your turbo intake becomes the only available source of negative pressure (though very little if you have a high flowing air filter).

Why you talk about it here and above claim it never comes that way from the factory? You must have made a typo?

I really don?t understand how you?re missing all of my points. This isn?t hard stuff to understand, you?re just refusing to acknowledge how these systems are setup or their flaws.

Based on your writing I believe you are blind to how the system is truly setup and how it should work. You do not understand some key points about oil molecule behavior, engine seal performance, and system flow vs pressure. It is not uncommon...

Do you know VW TDI engines have a habit of running away because they pool so much oil in the intercooler? Where could this possibly be coming from on a healthy engine?!?!?!. The CCV system on that engine is a hose with a spring loaded flow regulator routed from the valvecover to the turbo intake. But but but but it was engineered that way, it shouldn?t do that right? Well it does, because no baffling system is perfect.

Every turbocharged engine will find oil inside the intake pipe leading to the turbo intake. All skylines and all supra engines do it. All sr20 engines do it. It is very good to find a slight oil coating there! The engineers didn't design inadequate systems or inadequate baffles; the oil quantity which collects in those ducts on factory air-filter engines is negligible and should be routinely cleaned during 50,000 to 80,000 miles maintenance intervals to remove sticky carbon buildup (heavy chains which collect over time while lighter chains move on). It was determined by the engineers that those small quantity of oil which slightly coating the tube and compressor wheel on healthy, factory air filter engines (i.e. significant pressure drop) will improve the lifespan and performance of the turbocharger as a fine, delicate coat of oil is literally desirable in those areas. Oil molecules are able to fill small gaps and imperfections in the materials which assists in smoothing airflow at high flow rates, and protects against oxidation- it prevents interaction with atmospheric contents which would alter the materials of the turbocharger over time.
--> Working as intended!!