|
Have you seriously never pulled the intake manifold off an engine and seen and felt the oil varnish in it?
Those 1000-3000hp engines you speak of are dry sump, so no shit they have to monitor crankcase pressure. They usually pull 14in of vacuum btw. They monitor it and tune it because they can pull the bearings dry if they want depending on how the dry sump is geared. Damn, it?s not that hard to understand when you know the context.
I?ve seen data logs of crankcase pressure on my old shop?s wetsump 1100whp 4G63 with only atmosphere crankcase ventilation. 2-3psi. Wooptie fuckin do. In that application it?s a drag car, it sees that for maybe 10 seconds at a time. It has no air filter and never sees the conditions a PCV valve works in anyway.
If it?s connected to the intake manifold (how most engines are configured), the PCV valve is closed under boost mate. 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. 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.
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?. 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).
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. 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.
|