Quick Oil Catch-Can question

mdost03 · 07-12-2008

Alright, I think I know the answer to this, but just want to verify. Maybe the question is more towards Scheides since I am trying to mimick his setup almost from his EVO.

I bought this catch can and received it in yesterday:

Just wondering if I capped off the top filter port with a rubber vac cap if it would basically run like this one then (AKA Filterless):

The plan would be to cap off the top filter and then connect the valve cover breather and PCV lines together and route to the 1 port and then take the other one and hook it up to the vacuum line the PCV was hooked up to. Kracka vents would be put on both sides to make sure no boost enters the crankcase.

mdost03 · 07-12-2008

Bored while iPod Touch updates so I drew up a picture of how I want to route the hoses and everything. Is this the correct way to do it?

FattyBoomBatty · 07-12-2008

Why does it have two ports for hoses? If it's capped, why do you need two kracka vents?

mdost03 · 07-12-2008

Quote:

Originally Posted by FattyBoomBatty

Why does it have two ports for hoses? If it's capped, why do you need two kracka vents?

I thought all catch cans had 2 ports for hoses?

I want to cap the breather filter off so I can run a vacuum through the can to make it function similar to stock for the PCV valve and breather.

**asshanson** · 07-13-2008

From the looks of the diagram, it won't work under boost. In vacuum yea it'll suck out air from the valve cover, but under boost the air will have nowhere to go. You need to route the side port to the intake pipe to suck out air under boost.

EclipseGST · 07-13-2008

Instead of capping off the breather, run the vacuum line from the intake manifold to that. Then run the 2 ports on the side to the valve cover.

You could always set it up like you made the diagram, but instead of capping the breather, you could put a kracka vent in so under vacuum the breather is closed, but under pressure in the catch can, it opens. Like if you are getting pressure from the valve cover.

**Halon** · 07-14-2008

Quote:

Originally Posted by slowboy

From the looks of the diagram, it won't work under boost. In vacuum yea it'll suck out air from the valve cover, but under boost the air will have nowhere to go. You need to route the side port to the intake pipe to suck out air under boost.

Exactly. You are only venting the crank case when your engine is in a vacuum condition the way you have it set up. While under boost, the pressure that will build up in the crank case has no way out (Except maybe out your dipstick after it launches out.) I also don't see a need for an extra check valve both before and after the catch can. The one between the IM and Catch Can would be the only one you need.

mdost03 · 07-14-2008

After doing a little research on DSMTuners, I found that this way is probably the best way to go and is the way I am going:

**Kracka** · 07-14-2008

The newest design above looks like a good setup. We could design your setup to function like Scheides' but it requires the use of 4 Kracka Vents, a two-port catch-can (which you have), and a small breather filter (which you have).

mdost03 · 07-14-2008

Pics of the finished product:

Quote:

Originally Posted by Kracka

The newest design above looks like a good setup. We could design your setup to function like Scheides' but it requires the use of 4 Kracka Vents, a two-port catch-can (which you have), and a small breather filter (which you have).

I did give Scheides a PM a while back inquiring about his setup because I originally wanted to mimick it, but never got a response so I went this route instead.

**Halon** · 07-14-2008

Looks like a much better setup. I personally don't use a check valve on the turbo inlet as all it does is create more vacuum at idle/low throttle, but to each their own.

Have you considered a catch can for the turbo inlet line as well?

mdost03 · 07-14-2008

Quote:

Originally Posted by Halon

Have you considered a catch can for the turbo inlet line as well?

I was, but can't really find a place for a 2nd one in the bay. I might be able to mount it lower by the turbo, but not sure if I want to go that route or not. Do you have one there that you could take some pictures of so I can see how you went about running lines, mounting, etc.?

**Kracka** · 07-14-2008

Brandon (Halon) is running a single can thats divided so it functions as 2 separate cans.

I'm running a single can between my valve cover and intake pipe, but would like to run a 2nd between my valve cover and intake manifold if I can find the space for another can (or divide mine in half).

turbotalon1g · 07-14-2008

Why don't you guys Y them together into the catch then to a vacuum source?

**Kracka** · 07-14-2008

A vacuum source during one engine condition can become a pressure source during another.

**Halon** · 07-14-2008

Like Hughes mentioned, I have a single catch can that is divided in the middle, making it actually 2 catch cans in one. Here's the best picture I have of mine. Basically like your setup, but with a catch can on the Inlet, and no check valve there. Only 1 cheap check valve which is located where you have the other one, betweent the IM and the Catch Can.

Or you can also kinda see it towards the end of this video.http://www.youtube.com/watch?v=FoNOh750GHU

mdost03 · 07-14-2008

Ah ok, that makes sense then. Thanks for posting up the picture. I'll have to search around and see if I can find a smaller catch can for sale somewhere. Thanks for everyone's help!

turbotalon1g · 07-15-2008

Can u explain more please kracka? I am not 100% on what u are saying.

**Kracka** · 07-15-2008

Quote:

Originally Posted by turbotalon1g

Why don't you guys Y them together into the catch then to a vacuum source?

This would work fine while the engine is under vacuum, but during an engine load (boost) there will be no place for the blowby and crankcase gasses to go so pressure will build up. To fix that problem though I have a few ideas assuming the 3-port catch-can as pictured in the original post. The top nipple where the filter used to be can either be run to the intake pipe, or, a KV can be placed there between the can and small breather filter. This will prevent incoming air during vacuum conditions, but will allow pressure to escape (with KV/filter) or slight vacuum to be present (routed to intake pipe). Please let me know if this doesn't make sense, I typed this fairly quickly while at work.

**Halon** · 07-15-2008

Brownman, think about it, at idle the IM is a vacuum source. It is what is drawing the air out at idle.

Under boost, the IM is no longer a vacuum source, it's under pressure. Your PCV (basically a check valve), stops the pressure from going backwards. And now your vacuum source becomes your inlet pipe.

You need those 2 different vacuum sources because like Chris said, the vacuum source under one engine condition, can become a pressure source under a different engine condition.

Chris I just did some quick thinking about what you were saying with a 3 port catch can. Quick thinking about it, I think it'd work.