So for clarity's sake, I'm going to refer to the CCV in the middle of the block as the CCV/balance vent.
And the block port that feeds the PCV as the sump breather vent (SBV?).
Unless you or the Perrin guide has a better solution.
Yowie wrote:(1) So the valve cover breather baffles must be there to prevent oil surging out of them and into the inlet.
Almost certainly. There are also baffles inside the engine just before the crank vent for the same reason.
Yowie wrote: The idea is to deal with blow-by gas but keep the oil in the engine as much as possible. Obviously these baffles and even my catch cans are not perfect funk filters or some oil wouldn't be present on the "clean side" hoses after my catch cans.
I wonder how many efficient catch cans in series it takes to remove all oil residue & water vapour? It's a shame Mythbusters are not going anymore.
Yowie wrote:(2) I guess all the different hose sizes and restrictors in the system help to create a pressure differential in the PCV system with the majo vacuums being drawn at the PCV return in the inlet and the actual PVC valve in the intake manifold.
I would think so. I'm still intrigued by the factory restrictions in the crank F-shaped splitter and what is best practice (factory/some/nil restrictions) for a warmed-over road car. There are too many variables for my experiments to yield any answers.
(3) Another thread on LGT mentions that the heads/CCV balance pipe runs alongside the turbo coolant hose supply pipe in order to help evaporate sump condensation...
(4) To add to the complexity, there's also the loose-built engine factor.
(5) Would be interesting to use a PCV as a one-way valve on the cam cover breather return.
The simple answer is Provent filtered catch cans, but at what expense to PCV system efficiency?
Whereas you and others have an AOS/CC setup that may add complexity and drag on the stock PCV system and which still doesnt work perfectly or as expected.
Yowie - A lot of those drag & dyno competition cars just vent-to-atmosphere from the catch can on my understanding. Probably better for their application for a lot of reasons including octane preservation under maximum effort runs.
Ben - Yet pulling a crankcase vacuum yields HP gains?
Would be interesting to use a PCV as a one-way valve on the cam cover breather return. (Preventing flow from the heads to the inlet)
(1) But you said you still had some oil in the inlet and intercooler?
(2) I mean that adding hoses adds drag to the system, changing restrictors and pipes around affects the pressure differentials.
Yowie wrote:Sounds good to me.
Too many acronyms can be confusing though (even though I have said "PCV" a lot like a total hypocrite). If you're doing a round of editing perhaps consider using the long-form of each expression at least once per post.
(Not being a smarty-pants here)
So I want to say, if you really want to keep oil from pooling in your inlet, regardless of your catch can/aos setup, I’d consider putting a very high flow, large port diameter aos/cc inline with the bov return, preferably using some type of filter media that can handle the sudden pressure wave.
Yowie wrote:But are you saying that different pre-turbo pipes have different ported vacuum that materially affects the stock crank gas breather system?
Apart from some conjecture in the linked catch can thread about which spigots (described by size and proximity to turbo) flow more, I cannot see any evidence in that thread that (eg) Brand X aftermarket pre-turbo pipe affects the stock crank gas breather system differently from a stock pre-turbo pipe or a Brand Y pipe.
[Excluding the "blocking the flow" or "remarkably changing the plumbing" chat of course.]
Flatirons mentioned this in their videos, yes.
The FSM explains the intent embodied in the pcv engineering Subaru debuted with the gen4 turbo.
Yes KillerB have the option on their new hard inlet pipe.
If I would hook up a manometer between both ports, yes, we could confirm what subaru already took care of for us
Avo style inlets that differ from the stock arrangement:
Its yet another thing grandfathered in from another brand, model, or application.
Like mega heavy aftermarket swaybars and the valving on generic coilovers, you’re going backwards when you have the option to improve.
Using a Perrin or psr v2 silicone inlet (more affordable) should maintain the correct pressure differential in the inlet for the pcv returns, meaning less reliance on an aos/cc setup for a street driven car not running e85.
Users browsing this forum: No registered users and 6 guests