Originally Posted by chucky420

You'll have to hook that existing fitting on your valve cover to your intake pipe (best) or put a filter on it. Then, you'll probably have to get another fitting welded on to your valve cover and run that to the fitting on the intake manifold with an inline PCV valve in between. Nice job on the block.

Originally Posted by Markley02

If you need any pics or videos of the stock b16a3 just let me know. My car is still completely stock and I very much enjoyed your build thread.

Originally Posted by mik101

Background:

The breather box doesnt exist on b20b (or 96+ b18b as stated) engines. There are two passages on the back of the block (the two 14mm HEX freeze plugs on the back of your block go into them. These passages run from the crankcase to the head/valvecover. The line from your intake to the valvecover (which you have blocked off it looks like) supplies clean air to the system. On the B20B head the PCV valve is in the valvecover with a line to the intake manifold. By doing it this way honda eliminated the breather box.

Fix:

You can get fittings that fit where those freeze plugs go, from Honda. They are a coolant fitting for an older prelude. One side has a half inch (or 12mm?) barb on it.
This is how most people build a custom PCV system for B20Vtec (and 96+ ls/vtec) motors. You can get one or two of these (two really is only needed with turbo motors IMO) and run that to a sealed 2 port catch can. The other side of the catch can runs to the pcv valve, and that line goes to the intake manifold like normal.
This mimmics the factory honda setup for other Bseries vtec engines. (You still need to provide clean air to the breather port on the valvecover with this setup)

[Not to confuse people, but you can also add additional ports to your valvecover to accomplish the same thing -- which is what I did on my engine]

Pretty much as long as the crankcase can relieve crankcase pressure, you're good -- but having the crankcase under vacuum will increase efficiency slightly. The purpose of the valve is only to keep there from being too much vacuum on the crankcase at idle/deceleration/part throttle. Without it, the oil consumption would likely be high under these conditions.

Ofcourse the easiest way is to just open the breather port on your valvecover to atmosphere and just let it vent that way (do not need a pcv valve, do not hook anything up to the intake manifold vacuum source).

The downside to this is that you dont get the (mild) benefit of having a vacuum on your crankcase at idle/cruise, its emissions illegal in most places, and you will probably get a little bit of oil vapor coming out of your valvecover (which would be completely normal with this setup).

I'd personally just do it this way for now until you have your other issues sorted out.

Good luck man.