EnviedC6

I recently installed a MM catch can in the 'wild' format. Now if I get on it really hard (redline) and when I let off, I get smoke during decel. I have a cammed LS2 with FAST 102 and full exhaust. Could the PCV in the catch can be causing this? I haven't had this issue before when running the elite engineering can. I saw something about drilling out the PCV a step on some pics on the MM website, but didn't really give much info for that.

Millenium Z06

Smoke from where?

EnviedC6

Exhaust

dmk0210

Are you seeing any oil in your fresh air inlet line (green in the diagram above) or the intake vacuum line (blue in diagram)??

ganador01

Any pictures of the install? From the diagram, it looks like they are drawing from the oil filler?

Any good catch can setup needs to draw from both valve covers and be routed to atmosphere or back into the intake pipe/manifold.

A really good one is also in piped into the valley cover. Mostly needed for boosted applications.

Millenium Z06

Mine runs from the oil fill with a Rev Extreme CSS cap to the MM catch can intake. The PCV port goes to the intake bellows and the driver side is capped closed.

No smoke. I'd suspect that you're pulling oil into the intake from somewhere. Are you sure this is new? usually smoke on decel is valve guide seals

David@MMS

this opinion is not rooted on actual data / testing / facts, and could lead people the wrong way.

crankcase pressure is not made at the heads, nor need to be handled 'symmetrically'. crankcase pressure comes from the crankcase and as long as the heads themselves are not an airflow restriction to the crankcase, it will follow the path of least resistance and one adequately sized line is just as good or better than two small ones.
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the valley plate is about the most terrible place one should consider venting from for high pressure control. before you disagree hook a hose to it and blow.
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to answer the op's question look for oil in the top of the can(exit) or in the line connecting the can to the intake manifold. if that is clean and dry then of course the oil is not coming from the can or the pcv system. if you do find it there then lets talk about it picked up from the last email i sent.

usually you pull some oil over the engine rings and or valve seals during hard engine braking, especially on heads with less than wonderful intake valve guide clearance