Building an Oil Catch Can - Need Suggestions

[Kijona]

So I'm going to build an oil catch can to catch all the crap that comes out of the crank vent on my STi. I'm kinda thinking of going with copper for the material but I've also considered aluminum.

The important thing is that it's sturdy and can withstand some heat. I thought about using CPVC for its heat resistance, but I don't know if I can find 2-2.5" diameter CPVC.

I'm also going to need to fill it with some type of media that is not only chemical resistant, but also heat resistant. Lots of people use steel wool but I'd worry bits of it would break off and end up in my engine (blegh!). I'm thinking air filter foam, but also considered taking apart a cheap oil filter and using the filter media.

Any suggestions would be helpful!

[Slack]

I made a catch can for my explorer using an inline filter for pneumatic tools. You can pick one up from walmart for $10 or $20. Works great.

[Janx101]

That's a good crossover! .. handy dandy sight glass style too!

[Slack]

You don't need a filter either, the swirling action catches enough oil.

[Kijona]

Two concerns there. One, it's relatively small in terms of volume. Second, it's designed for air and water, so I cannot imagine that the material is chemical resistant. I wouldn't want atomized plastic in my engine.

Is there one made of glass & metal?

Maybe I can use the top portion of one of those, if I can find a metal one, and retrofit a different reservoir.

Also, you may be catching some of the oil that's already condensing as it reaches the catch can. Water and fuel are less dense, so those will pass right through without a filter medium.

[Slack]

Why not let the fuel get burnt? I was just trying to catch the oil that was blowing by. And there shouldn't be any water in your engine. Mine has held up fine for nearly a decade. No degradation of parts. If you want to go all metal they make them. They are pricey.

[Janx101]

How much oil, water vapour and fuel coming out of that pipe?! .. might need a head rebuild rather than a catch can?

[Kijona]

The amount of garbage that comes out of the PCV(s) would depend on the type of engine and/or configuration. For mine, which is a turbocharged H4, a LOT of crap comes out of the PCV and ends up being recirculated back into the intercooler and makes it less efficient.

Fuel does not ignite inside your crank case. The fuel, oil, etc.. gets dumped back into the intake which isn't really a good thing.