There are a ton of catch cans on the market, ranging from cheap to quite spendy. There is no reason for this, as its a really simple device. So after doing some research, I decided to use a air compressor water/oil separator.
So its a pretty simple mod. I will keep it brief with how I hooked it up to the car as its more or less specific to the BMW.
Your list of supplies will vary depending on application.
First off, the catch can itself: http://www.homedepot.com/p/Husky-3-8-in ... 5yc1vZc9n8
Then you will need any fittings that are required for your application. FYI, the catch can/filter takes 3/8 NPT or MIP.
And finally any hoses that go with the fittings you got. I used 3/8" heater hose.
Here is the filter:
Step one, remove the stickers:
Step two, Remove the twist valve thing:
Step three, epoxy or JB weld the valve shut. The valve works great with pressure from an air compressor, but not so much with vacuum from the manifold.
Step four, while the epoxy is drying, make your bracket. I happened to have an old metal shelf so I just needed to put a hole in it to hang the filter.
And Paint:
Step five, install your fittings, I ended up using a different fitting than shown.
Step six, install
Finally, the rest of the install is just routing hoses, and connecting to the engine. One side connects to the crankcase vent whether that is the valve cover or crank case itself, The BMW only had a Valve Cover vent, I know the L series has 2. The other side of the filter connects to the intake manifold.
I will update as I drive the car. Currently, my thinking is the filter may need a bit of modification to further help the separation of oil and air.
