How To Setup Your Catch Can Correctly

[Si Speed 317]

This has always been a hot topic of discussion, hopefully this will make everything clear and simple.

A 'catch can' is essentially just a can that catches any blow-by oil from your PCV (Positive Crankcase Ventilation) and VC (Valve Cover) ports. In our case, we want a ventilated catch can. A stock K20 motor's PCV valve is just that - a valve. It's actually a check valve. It's made to allow ventilation when your motor is in vacuum. When your motor sees boost (through forced induction, of course) this valve will close, preventing any ventilation from your PCV valve. We want this to be open during both vacuum and boost, so that we can get our blow-by to see our catch can instead of the inside of our motor/charge pipes/turbo. We are also going to route our VC ventilation port to the catch can. Here is how we setup our catch cans:



PCV Valve, #1. Remove the vacuum hose and this valve. Punch or drill out the guts. Cap off your IM (intake manifold) port, #4, and secure with a small zip tie. Reinstall PCV valve, and connect this to the port on the catch can, #3. Now, your VC breather, #2 needs to be connected to the other port on your catch can, #3. The only thing you need to figure out on your own is where to mount your catch can. Be sure to secure any smaller vacuum lines with a zip tie.

Hope this clears things up! Feel free to rep me, bottom left of my post


Also, I forgot to add that adding steel wool to the inside of your catch can helps separate the oil from the air. Definitely a good idea to add