Log in

View Full Version : lets discuss PCV systems... (LS1 guys please)


qwikz28
05-07-2007, 12:58 PM
ok i'm absolutely stumped about PCV systems. its such a hotly debated topic on tech and everytime i ask questions about it, it turns into a pissing match against who's setup is better. the only thing i know for sure is that i wanna delete the system. i want my car to have nothing to do with it. that being said, i have a few questions...(actually, alot of questions)


i know i have to install a breather system in my car and i know i have to plug up the PCV lines. but, what do i do with the actual valve itself?

is there even a valve?

what about the valley pan?

should i upgrade to the LS6 pan?

are the two banks vented together, or do i need two different breathers?

i'm sure i have more questions but i can't think of them at the time... can any ls1 guys shine some light on this topic please? this is baffling me

bubba428
05-07-2007, 01:03 PM
ahhh Possitive Crankcase Ventilation....I belive you can't modivy the routing on an LSx engine...but there are a few thing non of which ad power

Tru2Chevy
05-07-2007, 01:15 PM
ahhh Possitive Crankcase Ventilation....I belive you can't modivy the routing on an LSx engine...but there are a few thing non of which ad power

He isn't trying to modify the routing - he's trying to delete it, and he's asking for those who own/work on LSx engines to give him advice over which is the best method for doing so.

- Justin

bubba428
05-07-2007, 01:22 PM
delection is moification...but you CAN"T because the PCV line goes to the throtle body...unless you caped that off and then you may have issues with air in the oil pump at high rpm

qwikz28
05-07-2007, 02:08 PM
delection is moification...but you CAN"T because the PCV line goes to the throtle body...unless you caped that off and then you may have issues with air in the oil pump at high rpm

hence the breathers...

Bandit
05-07-2007, 03:42 PM
Jay Fisher modded mine when I first bought the car Re-routed it and added a larger PVC, something about the OEM system sucked on our cars.

BonzoHansen
05-07-2007, 03:56 PM
What purpose does deleteing PCV serve?

qwikz28
05-07-2007, 07:27 PM
What purpose does deleteing PCV serve?

they suck because they route the fumes and oil into the intake. the oil can get in the combustion chamber and cause detonation in some instances. granted most people have had more success deleting them, i see no purpose in paying to upgrade them.

ins0mnia24
05-07-2007, 10:29 PM
I run a Metco screw on breather on the oil fill along with another breather filter on the the back of the driver side valve cover..
I wish I did it sooner because it solved all of my oil consumption issue's..

qwikz28
05-07-2007, 11:17 PM
if its not too much trouble, could you go into detail about what other mods you did? did you change the valley pan?

Mike
05-08-2007, 08:08 AM
jake when i just did my intake swap, there was absolutely no oil in the intake or tb......

bubba428
05-08-2007, 08:10 AM
you only get oil if you pcv valve is shot

qwikz28
05-08-2007, 09:40 AM
jake when i just did my intake swap, there was absolutely no oil in the intake or tb......

i didn't check mine. but i do have oil consumption issues that i assume is related to the pcv system

BonzoHansen
05-08-2007, 11:49 AM
I kind of agree with above about oil & the pcv. A bad one will let oil through. However, I don't know the LS motors yet and therefore don't know if they have any inherent design issues related to pcv. I will say on a SBC motor I had with valve covers with no baffling, and I had oil issues. I fabbed baffles and problem solved.

Batman
05-08-2007, 09:46 PM
I would just put a catch can on it

qwikz28
05-08-2007, 10:57 PM
I would just put a catch can on it

is that what you have? i've been reccomended to delete the PCV system. I'm so confused :(

JSPERFORMANCE
05-09-2007, 12:42 AM
If you delete the system you must cap off the vacuum source for it. Then you must add as many breathers as possible. The pcv is designed to draw the moisture and excess pressure from the crankcase. The problem is not actually in the design but in the fact that these engines rev so high that they create enough crankcase pressure to allow more oil vapor to the pcv than designed. There is an update pcv valve and there is also the option of the ls6 system which locates the draw source to the valley pan these both work fine but are just a band aid for the real problem... BLOW BY.. If you delete the system you may want to decrease your oil change intervals since there will be nothing there to remove the moisture from the oil which could cause a problem with sludge.

ins0mnia24
05-09-2007, 01:05 AM
The ls6 pcv system is a waste to because it will only reduce the oil consumption a little bit better than the ls1
Both LS1's and LS6's have the same oil consumption issue's that is why the revised the service bulletin's later on to include the LS6's also
That is also why owners of either or are having to resort to catch cans or deleting the pcv.

The revised pcv valve gm part# 12572717 which is a None check ball type pcv valve it just has a hole drilled in to it should be used along with the Gm vented oil cap for it work effeciently but I forget the part number for the cap
I ran that set-up it only improvd the oil consumption a little bit which from what I read is a hit or miss with most people trying it

qwikz28
05-09-2007, 07:40 AM
yeah i'm pretty certain i'm just gonna delete the system with a breather on either bank... but whats the idea with the updated valley pan? is it worth it granted i'm deleting the valve altogether?

ins0mnia24
05-09-2007, 10:13 AM
No it isnt worth it if you end up running a breather set-up..
Unlike the LS-1 pcv that takes the pressure from the valve covers the LS-6 pcv and work by taking the pressure out through the valley cover in between the cylinder heads..

The difference between the LS-6 is the Valley cover has a black box/oil separator in the center which attempts to remove the pressure out without sucking oil.. But LS-6's do consume oil also

When you run that you end up plugging off both valve covers from the pcv system.

Batman
05-09-2007, 10:52 AM
is that what you have? i've been reccomended to delete the PCV system. I'm so confused :(

I have the LS6 PCV right now, but I am still consuming alot of oil so I am in the process of getting a catch can and a breather. Personally I don't like the idea of deleting PCV unless you plan on doing oil changes alot. I think it will greatly up your chances of building up sludge in the bottom end. I should have the catch can next week, I'll let you know how it does.

qwikz28
05-09-2007, 12:46 PM
will this setup work efficiently?: the stock ls1 PCV system, a catch can to catch the oil, and a single breather to relieve the pressure? i'm thinking this would provide a solution to both the oil consumption, and the pressure, but then i worry about unmetered air getting in the engine. would that be a problem?

ChickenLittle
05-09-2007, 11:05 PM
i wanted to run a larger PCV valve and hoses....but wasn't sure if this would help or hurt. I get a lot of oil in the intake, but figured breathers would not vent enough of the moisture build-up since vacuum is eliminated...thoughts? For those who've done this and succeeded, what parts should I use?