just looking for a definitive answer, on my 01 z06, is the pcv system in the valley or is there supposed to be an external pcv valve?

 

External valve off that is between the valley cover and the passenger side of the intake right behind the t-body

 

can anyone else confirm this, perhaps with a picture of theirs?

The reason I ask, is that I have no external valve on my car, simply a catch can, and I am chasing an oil comsumption issue (I am aware that the stock 01's burn oil sometimes, but this is a LPE built motor).... if I am supposed to have an external valve, that could explain my oil issue!

 

Judging from this picture... The valve is on the outside on an 01... still doing some more searching but it seems as if I don't have a pcv installed at all on my car

I will have to rectify this asap and see if it changes my oil consumption at all, checked today and most def had oil in the trottle body!

 

[QUOTE=airbrush1;1578547545Judging from this picture... The valve is on the outside on an 01... still doing some more searching but it seems as if I don't have a pcv installed at all on my car

I will have to rectify this asap and see if it changes my oil consumption at all, checked today and most def had oil in the trottle body![/QUOTE]

The pcv valve is inside the large rubber bulge nearest the intake in the first picture.

I run an LPE engine also with a catch can off the pcv pipe and another breathered catch can off the valve cover. The switch from 10/30 to 10/40 Mobil 1 cured my oil usage problem.

 

Lpe reccomends 15/50 for my 427 according to my paperwork... I believe that I will do an oil change again and add the pcv today and see how that goes! I imagine that the previous owner ditched it accidentally when he added the catch can to the car!

 

Ok, got a pcv installed yesterday, what a pain in the butt when you don't have the oem hosing!

Doin an oil change today and we'll see how it works on my consumption issue...

on the above picture, I see that the pcv goes from the catch can to the manifold, mine is coming from the valley port to the catch can, and then to the manifold out of the lower catch can port. Should I switch this around?

Also, should there be a hose from the driver valve cover at all? or is the valley port enough? I see lots of people capping off the upper port on the throttle body and also the port from the pass valve cover? what is the purpose of doing this?

 

LS1s port from the manifold and LS6s port from the valley. Your hoses should run from the valley port to the top of the catch can and from the bottom of the catch can back to the manifold.

There is no hose from the drivers valve cover, but there should be a hose from the passenger's valve cover to either behind the MAF or to a breathered catch can. (Or put a breather on the oil fill cap, but that can make a messy engine compartment on some cars)

 

Ok thanks much! That's how I have things routed at this point. What's the advantage of using a breathered catch can for the valve cover port?

 

With Forced Induction, you need to vent the crankcase blowby. The factory setup vents the pass valve cover to the TB. This won't work during boost, so you cap that line and vent the valve cover to atmosphere or the air cleaner for smog purposes.

 

It vents the crankcase blowby (minimal in a normally aspirated engine) without making a mess in the engine compartment. The stock system vents to the intake behind the MAF and any oil being vented ends up in your intake manifold.

 

Hope this answers some questions:

Understanding the evolution of the LS series
crankcase ventilation system


I'll address GM's path to improving the oil ingestion issue, but the trade off is less effective crankcase evacuation. The goal of balancing proper evac with ever stricter EPA emission rules makes this a trade-off.

First with the introduction of the GenIII LS1 in 1997. The crankcase evac route was drawing it from both valve covers at the rear of each with the fresh make up air drawn from the top of a tube on the throttle body. This allowed a great deal of oil intrusion from both the valve covers & through reversion into the TB in front of the blade.

The next revision came with the LS6 and the valley cover. This helped some with the oil ingestion, but the trade-off was a far less effective crankcase evac as the drivers side valve train got virtually no flow through to flush & evac the harmful combustion byproducts, and the early valley covers allowed to much oil to be drawn out with the gasses. Enter the LS2 and a redesigned valley cover with a baffle system. This worked quite well and minor changes to the newer releases helped as well. Leaving us with the same issue of the drivers side valvetrain not being flushed properly, but the 90mm TB had the fresh air tube eliminated and the make-up air drawn from the intake air bridge. This still allows some ingestion at WOT when the intake manifold vacuum is at its lowest. The L99 then went to drawing from rear of the drivers side valve cover and a still further improved baffle in the valve cover. This solution at least allows proper flushing on both banks and the crankcase itself. Picture the fresh air entering the front of the passenger side valve cover, flowing around the rocker arms, down the pushrod valley, through the crankcase, up the drivers side pushrod valley, around the rocker arms, and exiting the rear of the drivers side valve cover and pulling (flushing) the harmful combustion byproducts out. The problem is the flow is limited and the evacuation still inadequate. When allowed to flow at an effective rate the oil ingestion rises and the problems caused (listed in the earlier posts) are still an issue.

Also, the LS3 STILL pulls from the valley cover which is not all bad except the fixed orifice is to restrictive to allow proper flow.

Now on to the catchcans on the market.







First are the Home Depot/Lowes plastic air compressor separators. These will catch oil, but due to the extremely small size they cannot prevent the majority of oil being pulled through. Take a drinking straw and put a teaspoon full of water in your mouth. Blow it out and almost all is forced through the straw and out. Same with oil. The velocity, or the speed of the flow carries any liquid with it. Now do the same through a piece of garden hose. You will have a hard time getting much at all to force out (as long as you don't tip it down and let gravity help). This is due to the velocity of the flow. measured, the flow may be the same when measured at the inlet & outlet of either, but the internal volume of the hose is much greater than the straw so the velocity slows enough for the droplets to settle and not be puled, or forced through where the straw blows it right out.

Same with a catchcan. The smaller the internal volume, the less effective it can be no matter what the filtering or other internal design. It is simple physics.

Next, most have a mesh filter media inside. This works well at first, but soon becomes saturated and then as the droplets fall to collect in the bottom for removal, the outlets are maybe 1/2-1" from the media so many of the smaller droplets are pulled right out the outlet and into the intake manifold. These can be modified with a simple deflector to help prevent much of it, but the small size still allows the flow to speed through to fast for all the oil to drop out of suspension.

Then there comes the larger liquid overflow cans with 2 fittings added but are empty inside with little to no baffling. These catch a good amount of oil due to the slowing of the flow, but 20-30% of the oil still flows right through as it takes the path of least resistance.

The best cans have a large capacity (near 1 qt or more), a way to evenly disperse the vapors as they flow through so they make as much contact with the cooling surfaces to condense the vapor/mist to droplets. Then the inlet & outlet must be as far apart as possible to prevent pull-through. Out of the cans on the market, we have tested most everyone we come across and after testing (run on the same car for the same drive with the same type of driving with a clear glass inline fuel filter plumbed between the can outlet and the intake manifold vacuum fitting. This shows the amount of oil pull-through) we cut the cans lengthwise on a band saw to examine the entire makeup of the can. We found the air compressor type plastic units only catch app 40% of the oil. Next the smaller billet cans had quite a bit of variance with say the Elite catching 70% or so, but the near identical looking Billet cans (a few different names) only caught maybe 50-60%. Dissection quickly showed the Elite can had the inlet entering a separate filter media chamber and the outlet drew from the containment portion so that separation made a huge difference where the billet units have the inlet & outlet in the same small chamber the filter media is in so it was pretty obvious. The cans look just amazing in quality and exterior appearance but are the least effective of all the small ones/ The Elite beats them all as far as the small ones.

Then the Mike Norris/CCA/ came in as the best of the filter media cans. Similar internal design as the Elite but appx twice the interior volume so they catch more and allow less pull-through. Catching as much as 70-80% plus of the oil. These are the best hands down of the filter media cans (except we have yet to test the shorter larger one a member posted here that looks like it will equal or exceed the others).






Then only 2 come in allowing almost NO or NO detectable oil through. The Saikou Micchi (excuse my spelling) which as a center perforated dispersion tube running down the middle and the outlet app 6-7" away at the top of the can. This works awesome but they have added filter media in the past year and we see some oil pull through now that wasn't coming through before the media. This we attribute to the oil saturated media allowing droplets to pull through.

And the RX system that catches 95-98%. This I am the engineer and developer of. It is similar to the Saikou Micchi, but has a separate outlet chamber and diverter tube separating the inlet & outlet from the containment collection chamber. The vapors flow through the center, are dispersed out the perforated tube, make contact with the diverter tube to cool and condense the vapor/mist to droplets, then it travels along the outer walls evenly up into the separate outlet chamber and exit through an integrated checkvalve that prevents reversion and also controls the amount of flow.





Here is some info on the challenges & solution for FI builds:

The 2 different FI models of RX oil separator

You have 2 styles of FI can. The top mount super chargers (Maggie, KB, Whipple, E-Force) directly pressurize the cylinder head runners so no intake manifold. This requires only 1 check valve as your only dealing with the crankcase evac and the excess pressure in the crankcase. The RX can will evac at all operation levels using the vacuum provided by the top mount head unit itself and will prevent any back-flow or reversion.
*
For the turbo or front mount super charger you have a completely different set of challenges to overcome and the RX dual valve unit is the ONLY oil separating can on the market to address this. The turbo/SC pressurizes the OEM or aftermarket intake manifold when building boost and besides the additional blow-by resulting in excess crankcase pressure, you also have any connection to the intake manifold allowing the boost to leak into the crankcase causing even more issues. When your at idle or non-boost cruising the intake manifold is not positive pressurized and acts as a NA application providing the vacuum needed to evac the crankcase. But when in boost, the intake manifold is pressurized and there is no vacuum source. The kit manufacturers of these (STS, ProCharger, Vortech, etc.) just send a check valve to close when under boost, but this prevents any effective crankcase evac and not only is there the pressure to deal with, but the harmful combustion byproducts are left in the crankcase where they cause damage over time.
*
The RX can uses the intake manifold vacuum for evac during non-boost operation, and when boost is detected it closes the valve to the intake manifold and the second valve opens using the inlet side of the head unit (turbo/SC) for a vacuum source so no matter what the level of operation the crankcase is evacuated and excess pressure is dealt with. When you let off the gas and fall back into non-boost operation the valves open & close in just the opposite ensuring no oil into the intake system AND proper crankcase evacuation at all times.
*
The problems with the solution the FI manufacturers include is it is only effective at part of your operating and results in excess crankcase pressure carrying oil vapor/mist into the intake air charge when in boost so you experience detonation and the rest of the issues related to oil ingestion.
*
Now, for a breathered can. The ONLY time you would use a breathered can is if you have a external vacuum pump that is evacuating the crankcase and this pressure is bled off into a liquid*overflow containment container that needs a breather to allow the pressure to vent out.
*
There is NO time that this would be effective on a NON vacuum pump application. Those that do this are only relieving excess crankcase pressure and are NOT evacuating the harmful combustion byproducts so unless it is a race/track only build using a external vacuum pump and yes, we offer this solution.
*
To sum it up, anyone trying to use breather only or a breathered catch can on a non vacuum pump motor are never removing the unburnt fuel, carbon particles, sulfuric acid, and the other harmful byproducts that accumulate in the crankcase from running.

 

^ great post! thanks much!

I wonder if one would be well served to remove the drivers side valve cover and drill/tap it for an AN (or other fitting), run a line behind the manifold and around to the existing pcv stsyem in order to aid in evactuating some crankcase pressure?

it seems to me that there is great room for improvement to the factory system!

 

That would be difficult as you would probably defeat the built in baffel the OEM valve cover has so it would compound the problem as the baffel does a pretty good job.

With the right PCV crankcase ventalation oil separating system you should not have any crankcase pressure issues. On any built/stroked/or FI build the LS6//2/3 valley cover is far to restrictive to allow the crankcase to breath properly and as it draws from the center of the crankcase the drivers side valvetrain area does not get flushed properly so we generally cap the valley cover vent and pull from the drivers side rear of the valve cover so you get the best possible cross flow/flush through the entire crankcase and engine internal area. ( I know this goes against the popular LS6 valley cover swap many have used over the years, but think about it as I have explained and you will understand why).

Now, if you have a piston/ring/cylinder sealing/damage issue the only cure is to tear down and fix it. I start at #7 with a boroscope looking for signs of detonation and ringland damage. It only takes a few seconds during a tune to cause damage even though the car seems to run strong.

There is a ton of improvement that can be made on EVERY modern car & light truck domestic or import. The engineers are all aware of this, but the bean counters and the avg consumer will not accept the added cost and the extra maintanance step to drain the cans so I doubt much will ever be done. The oil ingestion issue has also created a great profit generating area for the service centers with the upper induction clean service (dealers charge $150-$250 PLUS for, and the do-it-yourselfer with SeaFoam, etc.) they reccomend every 10-15k miles to address the excess carobon and "gunk" build up from the oil ingestion.

Face it, most every car owner today except the enthusiests like are members here, drives their car to work/shopping/home and pay no attention to issues we are aware of so there is no real push to improve the current systems.

We see the mercedes Kompressor 4 cylinders are far worse, the new direct injection motors dont have the fuel mixture traveling past the intake valve so the build up on many like the Mini that upper end rebuilds are not uncommon by 50-70k miles now. Look at the shell or mobile commercials showing intake valves all cruded up by as little as 5k miles.

Keep the questions and discussions coming. This is one of the most misunderstood issues/systems with our cars today and most solutions are nad-aid approaches at best. :thumbsup:

 

I'd like to discuss EXACTLY what the pcv valve does... what changes its removal would cause, and any aftermarket options available. The GM replacement part as well as the stock one is oddly shaped and for someone like me whos' cars previous owner removed it and didn't leave the oem hosing in the car, its a pain to install.

IS there an aftermarket pcv valve that is of good quality? not neccessarily an oem replacement, but something more universal?

 

The RX system through Byunspeed has an integrated poly flow controlling checkvalve so it eliminates the need for an OEM style unit.

 

^I like it...