The front breather line can see both positive and negative pressure at the intake bellows, depending on engine rpms, throttle position and the vehicle's speed. I don't claim to know when the intake pressure in fornt of the throttle body is positive or negative as I haven't seen any studies, but I know enough to know it will see both conditions. In short, there will be moments when air and vapor is drawn out of the line from the cam cover, and times when the engine will draw air in the line from the intake.

Just remove your intake bellows (or hose, whatever you call it) where it connects to the throttle body and take a look at your butterfly valve. How do you think it got all black and greasy looking? Your air filter doesn't look that way. Oil vapor from the motor comes through the breather and condenses on the butterfly valve. In other threads where this issue has been discussed, many have concluded that we should have either two catch tanks, or one that has a divided chamber with two seperate inlets and outlets.

Some folks Y the two lines together and then connect to the one tank. I think that is wrong. The Honda engineers positioned the two lines on either side of the throttle body to take advantage of the different pressures that exist upstream and downstream of the butterfly valve. I would keep them seperate.

 

Why not just put a breather filter on the front side of valve cover like everyone has been doing for years on their Hondas. Before the AEM intakes were CARB certified they used to not even come with the hose between the intake and valve cover, they just came with a breather filter. No, it is not emissions legal but it does allow for both the positive and negative pressures seen there and it cuts down on heat in the intake. This combined with a catch can between the PCV and the intake manifold is the best solution IMHO.

 

hecash, where are you going to put your reservoir for the H20 injection?

 

I'm using the same tank for my water injection and running out of water is not a problem. Its surprising how little water is used.

 

For the street it is probably ok, but for those who race (autocross) in a stock class, modification of the crankcase ventilation system, other than the adition of a catch tank, puts you in a prepared class.

 

Both the PCV and the air inlet on the valve cover can dump oil into your intake. If you run on the track, you don't want either feeding into the intake.

Check this photo for proof:

http://www.honda-challenge.com/images/gall...nd7/image08.jpg

Also, the thing that is confusing to me about the valve cover being an inlet is that with my setup (since replaced) having just a hose with a K&N breather filter on it, it seems like air was being forced out of the valve cover. The K&N oil on the breather (red) was scattered all over the place which tells me that air is at least coming out of there, but I can't confirm if it is going in.

-Pete

 

[QUOTE]Originally posted by Yellow Streak
Both the PCV and the air inlet on the valve cover can dump oil into your intake.

 

[QUOTE]Originally posted by gernby

 

There goes that theory...

 

The only thing that I could come up with is that we were getting some blow-by because running the supercharger had loosened things up. We did a compression and leakdown on the motor and it was within specs. So, the short of it is, we got oil in both tubes and will be running them both to a custom catch can. I won't know until the catch can arrives if there will be any vacuum put on it - it may just serve as a vent. But, since I have the pros doing it, I will know that whichever way it is done, it is right.

-Pete