This will result in engine damage over time as you are only relieving excess crankcase pressure & are not "flushing" the harmful combustion byproducts (Sulferic acid being just one). You WILL end the oil usage from a incorrect PCV system, but will sacrifice your engine over time.

Correct on most. The open hoses hanging down will destroy an engine quicker than anything aside from pouring sand directly into it. At speed, due to the venturi effect, one hose will become negative pressure & one positive....so the negative hose will suck dirt, dust, water, sand, gravel, etc. directly into that valve cover and the long term effects are not pretty. Their are a few so called "expert tuners" that do this that haven't a freaking clue and are ruining customers engines. A proper PCV system MUST have vacuum pulled and a filtered fresh air makeup source...and to prevent oil in the intake a proper SEALED catch can that actually seperates and traps the oil mist/vapors. The Catrek can is just a simple Moroso overflow catchcan that you can buy in Jegs or Summit and is designed for catching water & oil on the outlet side of a belt driven vacuum pump ( as we use on drag set-ups) and will still result in long term engine damage as it does nothing to "flush" the harmful byproducts out of the crankcase. It WILL end the oil in the intake issue, but again, at the expense of your motor over time.

As your engine comes up to operating temprature several things happen. One, the water vapor & condensation in the crankcase will flash off to steam, and if you have a proper PCV system, the vacuum will pull this out so it does not accumulate in the crankcase. Along with the water vapor, unburnt fuel, combustion byproducts, and some oil vapor/mist is also flashed off so without a sealed system and a vacuum source pulling filtered fresh makeup air through the crankcase, and a PROPER (not just empty cans with fittings or to small of cans that cannot do the job properly) oil seperating catchcan inline to condense and trap the oil vapors. The water vapor and other byproducts as well as any unburnt fuel trapped in the crankcase will be drawn into the intake and burn't in the combustion process and out the exhaust with the oil trapped in a proper can.

Now IF you have a piston ring sealing issue or a valve seal/guide issue. EVEN if your engine is fresh, if the rings did not seat properly (and of course the piston to bore clearance and ring end-gap is incorrect) you will have excess blow-by and NO can can cure that issue. Yes, you can eliminate the PCV system....but you will not have the engine live near as long as a proper system.

405_Z06 is one of the few on any forum that actually understands any and all of this.

FAR to many incorrect opinions spread around and even though I have a great deal of respect for Carteks abilities & skills, they have this solutuion DEAD wrong unless it is on a track only car and oil is changed after every event.

 

I have the 90mm fast Tb and Intake. Yes my Tb has a port along with the vally cover driver and pass vc do as well. The driver vc only has one and the pass has two like the drawing showes.

 

The only difference for myself with this is Im not sure what vally cover I have. The motor was built for me with an LS2 block but not sure what vally cover would have been used. anyway to tell?

 

The valley cover of an LS2/3/7 has the fitting coming up from the front (like the diagram) and the LS1 has no fitting.

 

A big thank you to 405HP_Z06 and TLewis for all of your help and patience in clarifying matters! :-)

 

TLewis: I agree that without a vacuum pulling the PCV the oil gets contaminated faster, that's why you (I) change it sooner than the DIC suggests.

405 HP: Just curious, why a can on the clean side? The air has gone through the intake air filter, and has not been subjected to any oil sources yet?

 

You would need to change oil every few times of running the car. The amount of nasty stuff in there accumulates very fast if you don't. Just look back at our grandfathers cars....they went 50k miles and that was WITH a venturi evac down-tube and a semi filtered breather (the downtube came out the back of the valley and the breather was the oil fill. It was only wire mesh).

For a clean side oil seperator, the OEM filtered frsh air source is drawn from the top of the TB so there can be reversion pushing oil mist into the TB and thus the intake. The clean side seperating can will trap that ingress as well.

 

That picture looks messed up. The dirty side is feeding straight into the intake without a pcv ? And then its running a can on the vent from the valve cover?

The vent tube is the cold air return, its gets filtered through the air filter why run a can on it? Thats the green line in the picture. No need for a can there, direction of flow should make the can useless.

The line coming out of the valley pan needs to have the can and pcv.
The system needs to breath and thats what the vent tube is.

The line going from the valley pan to the intake is the vaccum source. the vaccuum source is what pulls the oil mist.

So you have a vacuum and a vent to allow the vacuum to work properly.

That vent tube goes to the TB and is on the front side of the blade on the TB. No vacumm but a clean air source since the engine is pulling vacuum and eating the air it needs to have a source of air to displace was is being eaten and that is the vent tube.

Maybe I'm wrong but thats my interpretation of the system and how its suposed to operate.

 

Ditto. Still trying to figure out what way to plumb this damn thing. diagram good or bad? Also what could be used to plug the back of my intake up? right now it has plumbing running from it and T'ing in with the PCV

 

Chris.....Chris.....Chris......You ARE wrong my friend. LS series valley covers from 04 to present have fixed orifice PCV valves built into the valley cover at the base of the tube. You can run an additional variable orifice PCV valve in addition to the the fixed orifice if you so choose. I'm not a fan of fixed orifice PCV systems and prefer the variable orifice valve. Flow is not limited by the size of the orifice which improves PCV system performance.

There is a very good thread where all of this is discussed in detail linked above. Take some time and read it, I don't want to retype all of that again. I hope this isn't another 'oil cooler and oil temperature' discussion.....

Concerning the clean side can, they are needed for road racing or any type of racing where high RPM's are maintained for long periods. The clean side will pull oil from the valve cover into the intake manifold just like the dirty side if PCV velocity isn't slowed sufficiently to allow for carry over oil to drop out of suspension. Flow within the PCV system isn't one-way. The clean side will flow in both directions depending on the pressure conditions within the engine. Anyone running open track events with the stock clean side PCV system will experience intake contamination.

SpinsB,
The diagram above is the best configuration for your application.

 

I don't understand how the PCV system is plumbed into the rear of the intake. Which port is it teed into?

 

Sounds like someone has it run different from the OEM setup and plumbed it into the back of the intake instead of the standard fitting. Just need to configure it similar to the diagram....or determine the flow direction (to the vacuum source) and then plumb in a seperating can between it and the crankcase outlet.

 

SpinsB,
Can you post some pictures of your current system plumbing and configuration?

 

I had always suspected that as I believe it was an issue on my car but with no solid proof.. couldnt bet on it(if ya know what I mean)

So your saying that vent tube on the valve cover was meant to have flow in both directions? or this is a results of higher sustained rpm applications and the factory pcv system cant handle it. ?

As far as the oil cooler your were not right about it but I wont get into it in this thread

 

03 and prior does NOT have a fixed orifice, which is why these came with an external variable orifice valve. The OP has an LS2 and all LS2 valleys have a fixed orifice restrictor.

What was the issue?

Yes. If dirty side PCV flow is backed up due to excessive crankcase pressure, the clean side will reverse flow. Clean side reverse flow is not desired, but if the dirty side doesn't have the capacity it will follow the path of least resistance.

Start a new thread and 'show me the money'. I want to see real data, not just conjecture and estimation......

 

This is not by design correct?

 

Correct, not by design but in reality.

No, still not correct for variable orifice systems. Regardless of whether the system has a fixed or variable orifice, the LS series will reverse flow on the clean side and contaminate the intake.

A fixed orifice is just a simple restrictor placed in the tube to limit flow. It will still flow in both directions, just at a different rate.

A fixed orifice PCV system is used to meter blowby from the crankcase into the intake manifold, where it would be consumed during normal engine operation. This system is simple in design and construction, and provides crankcase ventilation based on the size of the fixed orifice valve and the normal operating characteristics of intake manifold vacuum. The biggest drawback of this type system is that blowby production does not always match intake manifold vacuum characteristics.

One of the tell-tale signs of clean side reverse flow.

 

Yes I can do that. I will get some pics later today/tonight. At this time im not running a catch can just hooked up the way it would have been before the motor swap.

 

I don't think that's a fair analogy. First of all, that era's cars weren't needing a rebuild or replaced engine due to contaminated oil. I don't believe there have ever been many combustion contaminated oil failures at any time. I do believe that the reason for early rebuilds of those era's cars was due to lower quality parts which wore out. Today's engines use parts which last far longer and make the engine more efficient and produce much less contaminants. Better sealing top rings, hypereutetic pistons with tight bore to piston clearances, and most of all, better fuel and spark control via electronics Vs. carbs and point ignition. Our cars use less fuel to produce more horsepower and less emissions and contaminants.

If you can get an LS series engine to pass a sniffer test without cats (you can, I've seen it done) then surely it isn't producing enough contaminants getting past the rings and pistons to ruin an engine when the oil is changed at reduced intervals.

 

Your right on with the quality of parts, materials, and tolerances....but we do more voulme than most LS shops in the country and tear-down & build motors daily (7 in the engine room right now). We also have run one of the winningest big$ bracket teams (3 alky powered dragsters) for over 7 years and see the damage done. My points are not guesses or assumptions, they are fact seen time & again. I have been building street & race engines for nearly 40 years and have seen how these engines have progressed through pre, middle, and current emissions systems. We also campaign LS based drag cars throughout the Eastern US and run them to the limits week after week. W/out proper crankcase evac with a fresh air source to flush......you will get far less life out of your motor than the same motor with a proper system on it. I guarantee it.

Of course, you are certainly allowed to do as you choose to your own engine......I just don't want misinformation spread to others that do want to get the most life out of theirs.