2003 5.3 PCV Purge can

[solidaxel]

Is anyone using a purge canister on there PCV system?
Does it have to use the same size hose that is on the stock system?
Any pixs?

[BR3W CITY]

I run a catch can which is vented, but not an actual purge canister.

[solidaxel]

Is it on the PCV outlet and just vented, not returning to the intake manifold?

[Rich84]

I am interested in this topic also..I couldn't believe how much oil was sucked into the throttlebody of my 04 van.

[sprint_9]

Im running a catch can on mine, Elite Engineering E2 with a clean side oil seperator. I used 3/8 or -6 fuel line with mine. The stock stuff is a plastic line and doesnt really adapt without the right fittings, and is kind of a pain to work with.

My dirty side plumbs from the valley cover, to the catch can, and then to the intake. The clean side air intake to the engine comes in my valve cover. The black cap on my valve cover doubles as a clean side oil separator, and an oil fill cap.

[crakarjax]

Originally Posted by sprint_9

Im running a catch can on mine, Elite Engineering E2 with a clean side oil seperator. I used 3/8 or -6 fuel line with mine. The stock stuff is a plastic line and doesnt really adapt without the right fittings, and is kind of a pain to work with.

My dirty side plumbs from the valley cover, to the catch can, and then to the intake. The clean side air intake to the engine comes in my valve cover. The black cap on my valve cover doubles as a clean side oil separator, and an oil fill cap.

Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.

Source: https://ls1tech.com/forums/generatio...outing-ok.html

tl;dr you want the air to draw suspended oil vapors from the entire crankcase down through the rocker area and up through the valley cover PCV.

[sprint_9]

Originally Posted by crakarjax

Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.

Source: https://ls1tech.com/forums/generatio...outing-ok.html

tl;dr you want the air to draw suspended oil vapors from the entire crankcase down through the rocker area and up through the valley cover PCV.

In my case I dont have an open air breather, it is sealed with a 3/8 nipple to attach into my air intake after the MAF. Inside of it is a baffle and a stainless filter to stop oil back flow through the fresh or clean air side of the pcv system while under wide open throttle.

[BR3W CITY]

You Tube

[crakarjax]

I posted this on ls1tech.com but here it is:

[sprint_9]

Originally Posted by crakarjax

I posted this on ls1tech.com but here it is:

That picture is wrong, the green line which is the clean air side should go on the upstream side of the throttle body blade, or on the designated port on the throttle body if it is that type.

If it goes downstream of the throttle body blade and attaches to the intake then it will be under vacuum. The only port that should be under vacuum should be the dirty side. The clean side receives metered air not under vacuum.

[crakarjax]

You're right, but so is the pic -- forgot to mention that it's a truck intake, and that port on the TB opens up right in front of the throttle blade. Also sorry for the illegible text on that, this forum downscales images to save on storage costs :/

Regarding the breather comment it was in ref. to the video posted, it looks like they have a catch can with a breather on it!
Question though; under WOT are you saying that there's not enough intake vacuum to prevent backflow through the valve cover ports? I guess I didn't realize this.

[BR3W CITY]

Originally Posted by crakarjax

You're right, but so is the pic -- forgot to mention that it's a truck intake, and that port on the TB opens up right in front of the throttle blade. Also sorry for the illegible text on that, this forum downscales images to save on storage costs :/

Regarding the breather comment it was in ref. to the video posted, it looks like they have a catch can with a breather on it!
Question though; under WOT are you saying that there's not enough intake vacuum to prevent backflow through the valve cover ports? I guess I didn't realize this.

It does have a breather, and no its not an air leak. PCV is simply designed to recycle vapors that would otherwise be dumpe directly into the atmosphere. The dirty side is under pressure, so its venting out (not leaking in), and into the tank. The "clean" side does suck back into the engine, but this is air that would not be metered under either circumstance. The contents of that air (whether is blowby gases or "Clean" air) is irrelevant.

[sprint_9]

Originally Posted by crakarjax

You're right, but so is the pic -- forgot to mention that it's a truck intake, and that port on the TB opens up right in front of the throttle blade. Also sorry for the illegible text on that, this forum downscales images to save on storage costs :/

Regarding the breather comment it was in ref. to the video posted, it looks like they have a catch can with a breather on it!
Question though; under WOT are you saying that there's not enough intake vacuum to prevent backflow through the valve cover ports? I guess I didn't realize this.

I thought thats what the pic meant, just hard to see since its scaled down.

Yes under hard or wot conditions intake manifold vacuum will drop low enough that it can backfeed through the clean side. Not so much backfeed but crank case pressure will build and seek the path of least resistance.

Here is a pic of clean side, and intake valve, on my 5.3 LT in a 14 Silverado before I did any catch can or seperator. Catch cans and seperators are really worthwhile with a direct injection engine. You dont get the valve wash down in DI engines like you do with port injection.