Catch Can. Why only one valve cover?

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jasonp

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So I just just picked up a 2021 AT4 and was researching catch cans. Wondering why install a catch can that only is catching oil from the drivers side valve cover. Isn't all the oil vapor from the passenger side still venting into the air box and ending up in the intake track / valves?
 

Antonm

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Because air goes into the valve cover (the passenger side one) from a tube connected to the air intake (filtered air), and air/ oil vapor mix is drawn out of the engine through the other valve cover (the driver side one), then routed back into the intake behind the throttle body to be burned.

So putting a catch can on the passenger side valve cover would be totally useless as the air is going into the engine, not out, on that side.
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BlaineBug

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I have a catch can routed on my rig but I'm still confused about the route of flow. Looks like both valve covers connect to the air intake tube pre-throttle body. Those connections are left unaltered and connected in place. But then you have the catch can routed in-line in-between another line that connects the intake manifold to the engine block I am assuming. Still a bit confused.
 

Antonm

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What year and what engine? Also could you post some pictures of this, sounds completely different from mine and all the ones I've seen. I'd be interested in seeing this setup.
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BlaineBug

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What year and what engine? Also could you post some pictures of this, sounds completely different from mine and all the ones I've seen. I'd be interested in seeing this setup.
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2019 prior-gen body style with 5.3. There's the PCV valve below the throttle body and then the suction is from the intake manifold. You plumb these lines to the catch can, not the lines on top of the valve covers.
 

enginehead

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So I just just picked up a 2021 AT4 and was researching catch cans. Wondering why install a catch can that only is catching oil from the drivers side valve cover. Isn't all the oil vapor from the passenger side still venting into the air box and ending up in the intake track / valves?
isn't it a good idea of have the oil going onto the valve? how else do they get lubricated? there are valve stem seals on the tops of them. is it just me or doesn't that seem like the factory did that breather set up for a reason?
 

H1Chester

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So I just just picked up a 2021 AT4 and was researching catch cans. Wondering why install a catch can that only is catching oil from the drivers side valve cover. Isn't all the oil vapor from the passenger side still venting into the air box and ending up in the intake track / valves?

@jasonp my catch can setup pulls from both valve covers. Team RXP. American Made by hand in S. FL.

 

Antonm

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On a 21+ engine it is 100% totally useless, and serves no purpose at all whatsoever, in any way, to have a catch can connected to the passenger side valve cover (I'm not sure how to make that any more clear).

Air is going INTO the engine on the passenger side valve cover, hence why that tube is connected after the air filter, no freaking oil mist in that tube, its just clean air from the air filter going INTO the engine on that side. The whole purpose of the catch can is to separate the oil mist from the PCV gases before they are returned to the intake and burned. Since there is no oil mist on the passenger side (you know because air is going INTO the engine on the passenger side, not out of the engine), having a catch can there is as useless as **** on a boar hog.
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Hobert

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So I just just picked up a 2021 AT4 and was researching catch cans. Wondering why install a catch can that only is catching oil from the drivers side valve cover. Isn't all the oil vapor from the passenger side still venting into the air box and ending up in the intake track / valves?
@jasonp I installed the Team Rxp cans on my 2019 5.3 stock system. I installed clean and dirty side. Clean side small can is really for boosted applications (turbo/supercharged). I am not boosted and the clean side catches nothing ( as I was told, Guess I was future proofing). Dirty side does a great job. Pricy but I like my Rxp Cans.
 

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