Wascally Wabbit1
Drag Racing Champion
I haven't looked too much into catch cans or how they work but if there is a valve on the bottom could you not feed it right back to the oil pan? or is the oil compromised in some way?
You will read about people doing this and I believe there is even a kit to route back to your oil dipstick tube. This is a terrible idea. The point of the catch can is to catch water vapor and the little oil droplets that ride along on this vapor.
Routing it back to the oil pan is far worse than not having it at all. You would be reintroducing the moisture back into the oil and it would contaminate the oil very quickly. People always say..."well the moisture was there in the first place so what's the difference?" You have to let that moisture out. Normally it goes through the PCV into the intake manifold and is burnt up in the hellspawn of fire that is your combustion chamber.
Here is a good artlicle on the subject.
https://www.mishimoto.com/engineering/2016/01/blow-by-101-what-is-blow-by
The other option is to vent to atmosphere but the problem with that is, besides being a federal crime here in the US, it allows pressure to build up in the crankcase causing excessive blowby and power loss. The other problem with venting to atmosphere is that it may not allow enough flow out of the valve cover and again foul the oil due to water contamination. There are a lot of factors in this though such as the climate you live in, the size and type of motor and so on. On my catch can set up I was getting about a 1/4 cup of water a week. I could easily see how if that were not allowed out the oil would be compromised pretty quick. Venting to ATM also makes a big oil mess of your engine bay. Some people vent it down to the ground but if you do that you should also get a new license plate that reads "IMADICK" or in my town "IH8THEC" or "DYDLFNS".... Sorry I was having fun with that. I live at the beach so dumping oil on the ground is akin to just walking down on the beach and pouring a quart of oil in the ocean every so often.
I have an APR can and think it's the best design out there but it's $400. I no longer use the can on the car as I don't think it is super necessary on a NA car but it may be more important with the turbo. Really the GTI and TDI are the cars it helps the most as they are direct injection cars so it prevents the carbon problems associated with direct injection.
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