Thread: Crank Case Ventilation fully explained. (Naturally aspirated edition.)

gtswrx, I'll get to some more modifications, some of them good ideas, some of them not.

rnd2k, if your car is behaving poorly with the stock setup and performs better when you start removing things then it is a sign something is wrong with your engine.

As for factory cars with ITBs... I've never been able to study them in depth so I can't comment on them right now. I plan on researching them though.

the engine is brand new just 3000km but its far away from stock anyway i'll be waiting for suggestions about how to safely removing this )) thanks

Since people are itching to see the good modifications I will get to them next. However the good modifications usually don't involve removing anything or making it simpler. The good mods will be adding things usually. The only great way to "remove" things and keep everything copacetic is to replace pre-2000 catch can with a 2000+ valve cover as has already been mentioned. Or built some custom, good looking, well hidden, well fitting catch cans. I have seen few do this well.

There are ways to maintain the benefits of the system while removing all of the crank case vent stuff, but the typical way of doing that (a byproduct of going with a dry sump oil system) is very expensive.

Added two examples of "good" modifications. These mods can be combined as well.

Look forward to a better explanation of the idle air issue, and a couple more good modification ideas in the very near future.

Ben would it be reasonable to connect both sides to a single catch can and connect the catch can hose before the maf so that air is measured?

That's not good for a few reasons. You want to connect the "PCV" side and the "WOT" side to one catch can, and then connect the other port to the intake upstream/before the MAF?

You never want to connect any crank case hose upstream or "before" the MAF because oil will contaminate the MAF. Also the air in the system has already been "metered" once by the MAF so you'd be measuring it twice.

Maybe you meant to say you want the hose to connect downstream/after the MAF? In that case you can avoid the problems with oil in the MAF and double metering the air. However you still have one issue.

The "PCV" side of things is specifically designed to work with a strong vacuum under idle and cruising conditions. By connecting it to the same catch can as the "WOT" section then you've basically removed half the system. The crank case will never see a strong vacuum.

Gotcha, makes sense. Very good read.

what about putting 2 oil catch tanks on both hoses ?

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hmmm.....so by installing a RR valve cover on my non rrr will work & i can remove the oil catch can from the front of my block?

would there be any issues with doing this ^^^^ & also removing the EGR stuff completly?