5.3litre

iTrader: (6)

Ok what if you have an ls7 that has been converted to wet sump? I have a tube on the pass. side valve cover. One at the back of the driver side valve cover. One on my holley TB. And one at the front of my LS7 manifold. How the hell do i plumb all this in? thanks

405HP_Z06

iTrader: (11)

Don't you have a port on your valley cover?

5.3litre

iTrader: (6)

yes at the front. but it ties into a port on the ls7 manifold.

scatillac

iTrader: (12)

The valley cover vent is what GM refers to as the "dirty air" side of the syatem and is connected to the ~3/8" vacuum nipple on the passenger side of the throttle body.

The valve cover vent tubes are the "clean air" side of the system and should be connected to a filtered air source. It should not be connected to a source behind (at manifold vacuum) the throttle body. A lot of systems tap into the air intake tube between the MAF and the throttle body.

On mine, I have both of the valve cover vents connected via a "t" into a tube that is terminated in a small K&N filter residing in the CAI. There's a 3/8" barb x 3/8" NPT brass nipple with it's barb sticking through the CAI wall and the hose is attached there. The other side has been turned down so that that the little K&N has a smooth round surface to seat tightly. It's a small but non-metered air source when connected in this way but will be compensated for in the tune if you have it in place at that time.

There are no huffing issues and the (very mild cammed) engine uses no oil between changes (3k intervals).

Haans249

iTrader: (24)

That is 100% completely backwards lol.

The valley cover (dirty side) connects to the passenger side intake port, not the throttle body. This is where you can add your catch can.

The valve covers (clean side both passenger/drivers side) connect into a T and to the throttle body which is your filtered air source. No need to "tap" into your CAI tubing, so don't do that.

The filtered clean air side port on the throttle body is not a vacuum source. This is because the air comes from in front of the throttle blade not behind it.

You should consider correcting your PCV system so it actually works like it should

5.3litre

iTrader: (6)

Thanks for clearing things up. I have a few more questions though. I really don't wanna run a catch can. Is it a must? I have two ideas in mind to run my pcv system. Bare with me, as im not familiar with pcv systems.
My 1st idea is to run a hose from the valley cover to the passenger side nipple on the ls7 manifold. With no catch can. Then i was just gonna put a breather filter on the driver side valve cover and run a hose from the pass side valve cover to the throttle body. Will this work? Second idea is to run the valley cover the same way to the manifold with no catch can. But i was gonna "Tee" the driver side and pass. side valve covers like you mentioned and just run them to the throttle body. Once again using no catch can. Will either idea work w/o the can? I just want a "CLEAN" look. thanks

Haans249

iTrader: (24)

You should T both of the valve covers together to the throttlebody. That is the correct way to do it. You also don't need to run the catch can, only if you're having some bad oil consumption issues, although it is recommended to run one regardless to keep as much oil out as you can as oil reduces the efficiency of the intake charge.

Sounds perfectly fine.

5.3litre

iTrader: (6)

alright cool. thanks man

405HP_Z06

iTrader: (11)

Here's a visual view of your configuration without a catch can.

5.3litre

iTrader: (6)

That is great info. thanks man

good2go

Hey Aaron: you wouldn't have a similar diagram of the LS7 with dry sump connections would you? I'm considering deleting the PCV and running breathers.

405HP_Z06

iTrader: (11)

I made a mistake on the original diagram. I corrected it and reposted. Sorry.

405HP_Z06

iTrader: (11)

Do you mean the stock LS7 dry sump PCV system routing?

scatillac

iTrader: (12)

Haans249,

My configuration is exactly like the diagram that 405HP_Z06 posted except that my clean air side is terminated in a small filter. Actually taking the time to reread my description will help you clarify things.

My having omitted "manifold behind the" in my sentence describing where the upper end of the dirty air tube is connected may have added to your confusion.

I also fully understand which side of the TB has manifold vacuum (BTW...my GM 90mm DBW throttle body has no nipples on either side of the blade) and I chose to route my hoses to a separate filter instead (so I could manipulate with the cylinder case vacuum if need be) and my system works just fine, thank you, it's just not a closed system like the factory stuff.

My motors run clean and they stay together . LOL

good2go

Yes. I'm getting lot's of oil in the intake. I'd like to end that problem.

ramairws6

iTrader: (33)

So where would the correct place be to introduce the catchcan in this diagram?

405HP_Z06

iTrader: (11)

Single or dual catch can configuration? If single, clean or dirty side catch can?

405HP_Z06

iTrader: (11)

Here's the stock LS7 dry sump PCV and vent line configuration:



If you're having carry over oil ingestion problems, this most likely won't do you any good. You will need GOOD catch cans to help alleviate the problem. If the engine has excessive blow by problems caused by mechanical issue's, cans and breathers will not help.

good2go

Thanks for the drawing, that helps. What do you think about just capping off both sides of the blue dirty side line and putting breathers on both valve covers? That way, I wouldn't be introducing any additional unmetered air into the engine, just equalizing any pressures and venting from the valve covers.

Haans249

iTrader: (24)

If you read your original post, it says, "The valley cover vent is what GM refers to as the "dirty air" side of the syatem and is connected to the ~3/8" vacuum nipple on the passenger side of the throttle body."

On the vehicle that he was setting his PCV system up on, there physically is a nipple on the passenger side of the throttle body. So your description of how its supposed to be hooked up was completely wrong, no confusion on my part. No amount of "rereading" your description would clarify anything as your clean side is ok, but, it would only confirm wrong information on the dirty side. I have no idea what vehicle you have or what throttle body you have, so when you said "connected to ... passenger side of the throttle body" to the original poster reading that would interpret it as, "I should have my valley cover vent hooked into my throttle body nipple."

Also, I know that some systems tap into the the CAI tubing, the original posters setup does not. I was not telling you not to do it, I was telling him. If you have it hooked up properly, great, I'm glad you do. But as far as providing the right information to the original poster, that was not done

As far as my motor goes, its unfortunate when someone puts money into something to have it fail. I'm glad to hear that none of your motors have let go.....yet. But man would it suck if one did, wouldn't it? I only hope for your sake that you don't have to go through my pain because Murphy would have really fucked you. Next time you should omit yourself from a conversation if:

A. You can't tell from a posters description whats going on.
B. Give the right information and correct description
C. Not take offense when someone points out what you said is incorrect.

But, thanks for your clarification once its said and done.