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So I have an open air catch can. Intake and TB ports are blocked. Pic below (hopefully) it’s a cheap can than came from TPS motorsports w my long tubes. I’ve had this setup goi g for a couple months and I’ve been kind of beating on it for the past month. Even before it was living at 4500rpm on the track (HDPE events)
so I did a pull on the HWY earlier and laid off and the Hwy behind me was all smoke. 😳😳😳😳 oh snap “did I just pop this thing?”
laid off and cruised. All sounded normal. No odd smells. Other than regular oil and ORX exhaust.
pulled over when I got off the HWY and checked. All is normal. Oil and PS is normal. Nothing is wet…. Exhaust is dry. Nothing smells like oil. Catch can is dry. Oil pan drips a little but not much. Maybe some old oil from the last power steering job got blown back? Oil pan residual blew back on the exhaust?? 🤷🏼♂️
so I’m wondering, is this PCV system and routing sufficient to breathe at sustained high Rs? I just guessed. This catch can kind of sucks.
did a small 3rd gear pull on the way back to redline and it didn’t do it again. 🤷🏼♂️ No clue. But that scared me. 😅
PCV routing.
Last edited by Bayer-Z06; Jun 16, 2021 at 08:35 PM.
…. If the intake sides are blocked off, then the crankcase can breathe in and out as needed through filtered air: hence the open air filtered catch can.
Any pressure will be pushed out through the can, and if it needs to breathe otherwise, it has a filtered air source.
Last edited by Bayer-Z06; Jun 16, 2021 at 08:59 PM.
not with that attitude. It’s called Google. You can’t just plug off lines and hope for the best. They lines are there for a reason. How about you do some research about an LS pcv system.
Your pcv routing is wrong. Who told you to do it that way? These cans come with very specific instructions.
this didn’t come with instructions. It’s a cheap china can that was thrown in for free.
if it’s open air, then it deletes the engine side of the equation. Normally the engine would reBreathe its own crank fumes. In most of our cases, they breathe too much which is why we end up with oil in the intakes. If I were to connect this to the intake with an open element on top of it, it would then be “taking in unmetered air” and would most likely idle like crap.
In a “race” setup (no better word) they delete the intake ReBreathing side of things and the valve covers are connected straight to a catch can and not routed to the intake.
not with that attitude. It’s called Google. You can’t just plug off lines and hope for the best. They lines are there for a reason. How about you do some research about an LS pcv system.
I’m not new to this.
and you just chimed in with “it’s wrong” and left it there. Instead of showing me what’s so wrong.
I’ve seen these diagrams a million times. This isn’t my first LS. It can breathe in and out as it wants. It’s just not going back into the intake as it normally would. It’s not rocket science.
Last edited by Bayer-Z06; Jun 16, 2021 at 09:06 PM.
I’m not new to this.
and you just chimed in with “it’s wrong” and left it there. Instead of showing me what’s so wrong.
I’ve seen these diagrams a million times. This isn’t my first LS. It can breathe in and out as it wants. It’s just not going back into the intake as it normally would. It’s not rocket science.
if you think your plugged line is a return line, you need to read up about pcv flow on an LS. You probably blew a head gasket with this wrong crankcase ventilation.
Last edited by Coffeetqlk87; Jun 16, 2021 at 09:10 PM.
if you think your plugged line is a return line, you need to read up about pcv flow on an LS.
I know about the flow. The intake port behind the TB “sucks” the fumes from the crank case back into the engine to be burned and the fresh air is taken from the TB port thru the valve cover
Last edited by Bayer-Z06; Jun 16, 2021 at 09:09 PM.
It’s a shame they stopped making the fixed orifice valve that was on the 6.0s. That worked like a charm on my Last setup with the LS6 valley cover and I didn’t have a catch can. It didn’t ingest much oil at all. It’s out of production now or I’d just run that.
Last edited by Bayer-Z06; Jun 16, 2021 at 09:12 PM.
Here’s the way it should be plumbed, unless someone tells me I’m wrong.
The port you have blocked off on the TB needs to run to the front connection on the pass. valve cover. There should be a hose from the drivers side VC to the rear connection on the pass vc that then runs up to the catch can intake connection. The output line from the can runs to the manifold. Mines installed from the instructions I got from Mighty Mouse.
I’ll try that. I was just lookin at the MM setup too. I’ve seen race setups take the two valve covers and run it right to a can and call it good. But it seemed weird to run an open can in series w the intake manifold port. That’s what threw me. 🤔
I appreciate the informative post.
This really came with nothing. And there’s no baffles, there’s a separation screen between the upper and lower part. But that’s it. Cheap can
Last edited by Bayer-Z06; Jun 16, 2021 at 09:23 PM.
All the catch can really needs to do is stop oil from getting back into the manifold. The breather on the can stops it from building pressure. After my tune that was the first thing the tuner told me, get a catch can.
I can’t really tell what you have going on here but if this is an LS6 valley, the red should feed into the can and the blue feeds out of the can. You really need to fire whoever plumbed this can. They did damage to your motor.
Last edited by Coffeetqlk87; Jun 17, 2021 at 06:01 PM.
I did find this from MM. Which describes pretty much what I did minus the line changes. But I get what you’re saying. That ported vacuum line you illustrated in blue would essentially be taking fumes from the valve cover when you are opening the throttle.
I didn’t block the crank breather ports. Just the manifold vacuum and ported vacuum ports.
I don’t know why people make this so much more complicated than it has to be. It’s been overdone since this engine has been out.
but I get where you’re thought process is coming from.
Blue smoke after pull….. only once. PCV?
