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tunermt · 04-09-2020, 02:08 AM

Quote:

Originally Posted by Kingtal0n

I am not picking on you! I just want you to understand how pcv works so that you can properly care for your engine. I want you to have a very healthy and clean engine.

You are not keeping the crank case pressure low if you don't have pcv lol

When you run an engine, any engine, it creates blow by, which raises crankcase pressure above atmospheric

So say atmosphere is sea level 103KPA
When the engine starts there, with no pcv, the crankcase pressure will be higher than 103KPA for the entire time it runs.

This puts additional pressure on oil seals (creates oil leaks) and reduces the ring-seal (increased blow-by).
This also allows combustion byproduct easy access to engine oil which quickly becomes contaminated and broken down as partially combusted hydrocarbon fragments dissolve

You should never run an engine like that.
-Daily drivers use active manifold suction (for simplicity and low maintenance)
-Race cars use a vacuum pump

Sometimes these are combined with an active-exhaust venturi driver or electric pump but that is rare and adds complexity

heres a picture, pay close attention to the exact pressure numbers KPA, and the bottom where it shows with and without pcv in terms of KPA

You want to be below the yellow line (at sea level, 101.xKPA) at all times, typically 1 to 2.2" Hg or roughly 12-25" of water (its easier to set pcv using inches of water as a measurement)

I don?t think think your picking on me I just see you are confused about crank case ventilation options. Venting all crank case ports including adding more vents (an fittings you see welded into valve covers) is a very common and efficient way to keep crank case pressure low.
Recirculating to the intake (pre turbo) is also common but allows dirty blow by gas into the combustion cycle. Oem PCv set up using a check valve/connected to intake manifold is also ok but limited flow for releasing pressure from crank case when the engine is under load and check valve is closed.

Keeping doing your research my friend and you?ll find loads of information out there including data logs of people testing all types of catch can/crank case ventilation plumbing options.

The key to any wet sump oil system is keeping crank case pressure as close to atmospheric as possible while the engine is under the highest loads (most blow by). Only when you get into dry sump oiling systems are you able to create a vacuum condition in the crank case under high engine loads thanks to multiple scavenging pumps.
Using a vacuum pump to apply negative pressure to the crank case is something you’ll see to help emissions on newer vehicles during low engine loads. These small pumps can not keep up with crank case pressure during high engine loads and you will see crank case pressure climb as blow by/cylinder pressure increase dramatically. L