PCV/Catch Can/Crank Pressure

**Sarge** · 06-26-2009, 05:52 PM

Firstly...track down and kick the shit out of whoever "designed" that setup. All that is ...is a pretty blow job of a crank PCV....Guys PCV stands for Positive Crankcase Ventilation...a catch can separates the oil from the air prior to routing the now clean air back into your intake.....
All that does is vent crank pressure/gas/oil to the atmosphere.
Come out of those AN fittings to a Catch can (vented is OK) and then back to your intake.....all the vents do is relieve crank pressure thus allowing your rings to seal properly....when properly routed back to your intake the gas smell/stink will be gone....
You have a couple of options here...
Vent via the oil filler hole and run a unvented catch can...vent through a vented catch can.....but route either back to your intake.
I am curious how much oil are in those cans when you check.

**Sarge** · 06-26-2009, 05:53 PM

Originally Posted by Hi-Po

LOL, funny this comment just came up. I just finished my LS6 valley cover and system setup like shown on page 1. I COULD NOT get that stock cap off. My cap I bought has a area at the bottom to screw onto... something. Ill go back tomorrow and yank harder after a good nights rest when its not 330AM

Channel Locks and twist it off.

**BigIke** · 06-27-2009, 04:32 AM

There is alot of oil/water in the cans.

So do I need a PCV Valve in the valve covers? or can I buy the pcv can that i've seen on a vette site posted on the first page. Run two of them, and run them both into the intake before the blower?

**Sarge** · 06-27-2009, 04:22 PM

Originally Posted by BigIke

There is alot of oil/water in the cans.

So do I need a PCV Valve in the valve covers? or can I buy the pcv can that i've seen on a vette site posted on the first page. Run two of them, and run them both into the intake before the blower?

You bet...just run the cans...and return to the intake....

**Hi-Po** · 06-27-2009, 06:36 PM

Are you guys still running an actual PCV VALVE?

**Firebirdjones** · 06-28-2009, 08:22 AM

Originally Posted by Hi-Po

Are you guys still running an actual PCV VALVE?

Yep, I do on everything that came so equipped,,,,with the exception of the nomad which never had one to begin with,,,,just a downdraft tube and a couple of breathers on the valve covers in that case.

**silplu83** · 08-20-2009, 07:26 AM

Hey sarge great post this one should be a sticky!

Quick question I just got a catch can and oil cap breather. I still have the older LS1 style vally cover. I took off my throttle body and noticed that it seems like most of my oil is entering through the hose that goes from the top of my pass valve cover to the tb. So much so that it puddles in the bellows and drips on my belt. When I switch to an LS6 manifold I will probably swap in a LS6 vally cover then. For now how should I run the hoses? Should I just follow the setup in post #2?

**tatertot91** · 08-21-2009, 01:29 PM

Got a quick question,
Lets say for now if i left the breather hose running to the valve cover running from the throttle body, i just put a catch can or air/oil separator in line with the intake manifold, would i be OK or at least better than before? Not gonna get that breather cap for the oil fill for a while but still wanna get this done.

**Firebirdjones** · 08-21-2009, 08:14 PM

Originally Posted by tatertot91

Got a quick question,
Lets say for now if i left the breather hose running to the valve cover running from the throttle body, i just put a catch can or air/oil separator in line with the intake manifold, would i be OK or at least better than before? Not gonna get that breather cap for the oil fill for a while but still wanna get this done.

That's how I have both of my 4th gens. Just the oil seperator in line with the PCV valve. Still have the other hose connected to the throttle body. And only one of my 4th gens has the oil fill breather, the other is still the stock oil fill cap.

Seems to be working great on both of mine.

**tatertot91** · 08-22-2009, 12:39 PM

Originally Posted by Firebirdjones

That's how I have both of my 4th gens. Just the oil seperator in line with the PCV valve. Still have the other hose connected to the throttle body. And only one of my 4th gens has the oil fill breather, the other is still the stock oil fill cap.

Seems to be working great on both of mine.

Thanks , gonna try that way out

**silplu83** · 08-22-2009, 02:41 PM

Originally Posted by Firebirdjones

That's how I have both of my 4th gens. Just the oil seperator in line with the PCV valve. Still have the other hose connected to the throttle body. And only one of my 4th gens has the oil fill breather, the other is still the stock oil fill cap.

Seems to be working great on both of mine.

On your car with the breather filler cap did you notice any idle surge? I have noticed a little surging while driving it around. It seemed to settle down a bit. Maybe it had to adjust to the breather filler cap and catch can set-up.

**Firebirdjones** · 08-22-2009, 03:10 PM

Originally Posted by silplu83

On your car with the breather filler cap did you notice any idle surge? I have noticed a little surging while driving it around. It seemed to settle down a bit. Maybe it had to adjust to the breather filler cap and catch can set-up.

No I never noticed any surging or idle changes. Not sure if I should have or whether that's normal

**silplu83** · 08-23-2009, 07:00 AM

Well the surge is gone. Maybe it was just a fluke thing. Its running awesome right now. I just removed the PCV and went into the top of my catch can then out the side to the intake. I capped the vent between the pass valve cover and the TB and put on the filtered oil cap.

Eventually I will end up with a set-up like in the OP. When I swap out my LS1 intake for LS6 I am installing the LS6 valley cover.

**afattitude** · 08-26-2009, 03:32 PM

I was wondering Sarge, how did you get the filter to go straight into the valve cover? Where did the ugly black plastic go? I also dont have a cap on my drivers side valve cover. There is a line that runs from a rubber grommet and it connects with the line on the passenger side and then to intake. I also have 2 places on the passenger's side valve cover that i guess need to be capped?

**tatertot91** · 08-26-2009, 05:22 PM

Originally Posted by afattitude

I was wondering Sarge, how did you get the filter to go straight into the valve cover? Where did the ugly black plastic go? I also dont have a cap on my drivers side valve cover the line runs from the TB all the way to the drivers side. I'm confused.

You gotta remove the line from the throttle body to the valve cover and cap off both ends. Then you add a breather to the oil fill section. Then you can run your catch can in line with the pcv valve.

Plus i would also like to know about the black plastic that was removed on your valve cover Sarge.

**405HP_Z06** · 09-07-2009, 07:50 PM

Originally Posted by BigIke

SARGE-LS1 community I've got a PCV/Catch can problem

I've got a viper engine. The valve covers have been gutted there are no baffles or mesh. There is only an fittings with hoses connected to catch cans with filters on top of them. One catch can per valve cover. Also NO pcv.

The problem is the smell... my wife and kids are getting a bit sick of the smell and I'm tired of wetting down the fender well.

I've been looking at the catch cans without the breathers on them, where the come off the valve cover, into the can, through the trap and back into the intake.

Would this work on my whipple setup? I'd like to run the can's into my intake hat before the blower but after the throttle body.

Would this work or do i need a PCV, what should i do?
Thanks

Very nice engine you have there. This type of crank case ventilation is typical for many forced induction applications. The current PCV system looks nice, vents to atmosphere, but is not good at evacuating blow by contaminants from the crank case.

Did you reconfigure your PCV system yet? Do you have any available ports on the blower bonnet after the throttle body?

**405HP_Z06** · 09-07-2009, 07:53 PM

Originally Posted by shady milkman

Nice to see my PCV system diagrams have shown up on other boards.

These diagrams and others are available here: http://www.ls1tech.com/forums/genera...outing-ok.html

**shady milkman** · 09-08-2009, 09:06 AM

Originally Posted by 405HP_Z06

Nice to see my PCV system diagrams have shown up on other boards.

These diagrams and others are available here: http://www.ls1tech.com/forums/genera...outing-ok.html

Originally Posted by 405HP_Z06

Thanks shady milkman, nice to see my diagrams over here.

http://www.ls1tech.com/forums/genera...outing-ok.html

yes sir..they are all yours

**Sarge** · 09-09-2009, 05:11 AM

Originally Posted by 405HP_Z06

Nice to see my PCV system diagrams have shown up on other boards.

These diagrams and others are available here: http://www.ls1tech.com/forums/genera...outing-ok.html

You should see my oil data. It not only is on Ls1Tech it has been converted into numerous languages. yup...when we post on a public forum it becomes public domain property. I dont care....nice diagram for sure...

**Mark1si** · 11-08-2009, 02:50 PM

Sorry but I have a question. Not trying to argue just a question that I am sure has been answered in this LONG thread that I have tried to read through so please dont

me. But if you vent both valve covers can you not just plug the valley, intake and TB ports? Does the valley to intake port not introduce unmetered air? Not asking to make HP. Just wondering if it helps/hurts or does it even matter....