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Oil catch can?


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Don't know why GM feels the need to take something that works, and re-engineer it into a overly complex system that sucks oil into the intake even worse. Unbelievable ... :nonod:

 

They didn't change anything. All engines have a PCV system, your truck included, that injest oil through the intake from the crankcase gases. The difference is your truck isn't direct injected so the fuel that is entering the cylinders is constantly washing over your valves and keeping them clean from deposit buildup from the ingested oil. On our direct injection engines, there is no fuel washing over the valves as the fuel is injected directly into the cylinders so deposits are building up on the valves over time. The catch cans are meant to filter these out of the crank case gases so there's nothing to buildup on the valves anymore.

Edited by Silverado-Hareek
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I have ZERO hoses in either valve cover, so they did indeed change something there ...

 

My PCV valve is in the back of the drivers side valve cover next to the firewall, right in the block. The hose originally went from there to the upper intake manifold. That's it.

Edited by Jsdirt
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I have ZERO hoses in either valve cover, so they did indeed change something there ...

 

My PCV valve is in the back of the drivers side valve cover next to the firewall, right in the block. The hose originally went from there to the upper intake manifold. That's it.

 

Maybe you just can't see it but I thought I saw/read that the clean side separator was designed for your engine originally so there's a hose somewhere. GM maybe just changed the layout?

Edited by Silverado-Hareek
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I just got a really crazy idea....Why don't you purchase one and install, then run a scope through your Ecotec engine and let everyone know what you find.

When you finish, come here and post your findings with pictures. That way, you can prove your own point and not try to belittle someone that is only trying to help you out by posting a video that actually answers the question you had asked.

 

That's the dumbest idea I have ever heard. I am not about to buy a GD thing. There was no belittling in that old post of mine. There is belittling in THIS post, directed at you because you responded to a very old post! :)

 

Look, I have learned many a lesson from prior knee-jerk vehicle maintenance decisions in my past. I'm through with that crap. I need EVIDENCE of an issue before I turn a wrench or pay someone to turn one. And I also need evidence that said work actually corrects a problem.

 

My personal jury is still out on these catch cans everyone is spending money and time on. Sure, they catch oil, but are they actually reducing any oil deposits that are supposedly forming on the intake valves? No one can definitively say whether oil reduced in one area actually affects oil levels in another area. My guess is this stuff is a wasted effort.

 

If deposits are forming, I will be spending my money on cleaning at recommended intervals, whenever GM makes those recommendations...

 

Until someone can truly show ACTUAL EVIDENCE of deposit reduction besides how much oil is collected, I still think a lot of kool aid has been drunk up in this b!tch... But I was done talking about this a long time ago...

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Some photos on page one

 

http://www.camaro5.com/forums/showthread.php?t=347649

 

Please stop the personal attacks

 

 

Ryan

No "personal" attacks here! :)

 

But I must say that you are a better talker than a listener. You provide another link to a thread that does in fact show how these catch cans condense oil out of the air that they come in contact to. I never argue that fact. They condense oil vapor very well.

 

But let's have a serious discussion about the pcv system as a whole. This can pulls oily air from a specific point and returns air with what we can all assume is less oily than before. My skepticism comes from the fact is that these cans don't capture 100% of the oil out of the air that passes thru them and also only a small fraction of oily air is diverted thru the can, where it returns to mix with oily air again and then eventually will make its way to the 8 cylinders. Just because you are capturing some oil at a specific point in the can doesn't mean that the air that is eventually entering the combustion process is substantially less oily than without a can. Call me highly doubtful of this endeavor.

 

So, like I said before... If someone has actual visual evidence of carbon reduction due to a catch can installation, I am gonna pass on this round of kool aid!

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Maybe you just can't see it but I thought I saw/read that the clean side separator was designed for your engine originally so there's a hose somewhere. GM maybe just changed the layout?

If you look at the installation instructions for the '14 - up, it's 28 pages long ...

 

'14 + : http://www.eliteengineeringusa.com/content/Catch_Can_Install_Chevy_GMC_2014_5.3L_6.2L_Truck.pdf

 

For my truck, the installation instructions were a paragraph long (Conceptual Polymer unit). On EE's website, they don't even list installation instructions for the older trucks. It's so simple none are needed. Hook one hose to the PCV in the block behind the driver's side V/C, and connect the other hose to the top of the upper intake manifold. Done.

Edited by Jsdirt
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No "personal" attacks here! :)

 

But I must say that you are a better talker than a listener. You provide another link to a thread that does in fact show how these catch cans condense oil out of the air that they come in contact to. I never argue that fact. They condense oil vapor very well.

 

But let's have a serious discussion about the pcv system as a whole. This can pulls oily air from a specific point and returns air with what we can all assume is less oily than before. My skepticism comes from the fact is that these cans don't capture 100% of the oil out of the air that passes thru them and also only a small fraction of oily air is diverted thru the can, where it returns to mix with oily air again and then eventually will make its way to the 8 cylinders. Just because you are capturing some oil at a specific point in the can doesn't mean that the air that is eventually entering the combustion process is substantially less oily than without a can. Call me highly doubtful of this endeavor.

 

So, like I said before... If someone has actual visual evidence of carbon reduction due to a catch can installation, I am gonna pass on this round of kool aid!

Only a small fraction of oily air? The pcv system is nearly 99% of the oily air entering your intake and you're passing all of it through a filter that arguably catches 90%+ of the oil content out of it. So 90%+ of the oil, depending on your make/model can, is being filtered out. That's based on tests performed on the different leading brand cans. There's a link in this thread somewhere talking about that test. As for evidence of the valves, I'll have that in a year. I put my can on at 11,000 miles and I have 14,500 miles on my truck now. I'm about to get my mechanic to borescope my engine so I can see the buildup on the valves so far. Then he'll do a BG induction service to clean the valves and then borescope it again so I should get some before and after shots. In another year/15,000 miles I will borescope it again to see how effective the can is.

 

 

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Only a small fraction of oily air? The pcv system is nearly 99% of the oily air entering your intake and you're passing all of it through a filter that arguably catches 90%+ of the oil content out of it. So 90%+ of the oil, depending on your make/model can, is being filtered out. That's based on tests performed on the different leading brand cans. There's a link in this thread somewhere talking about that test. As for evidence of the valves, I'll have that in a year. I put my can on at 11,000 miles and I have 14,500 miles on my truck now. I'm about to get my mechanic to borescope my engine so I can see the buildup on the valves so far. Then he'll do a BG induction service to clean the valves and then borescope it again so I should get some before and after shots. In another year/15,000 miles I will borescope it again to see how effective the can is.

 

 

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Please keep us posted on the results. Thanks.

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The pcv system is nearly 99% of the oily air entering your intake

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How can it capture 99% of your air if it is only on one side of your engine? So let's pretend that it is actually effective in filtering oil. So now your driver's side intake valves are cleaner than your passenger side intake valves? How can this be beneficial? I think balance-wise, I would want both sides of the cylinders putting out the same levels of power...

 

I am interested in seeing your experiment results. Real proof of cleaner valves is more than just showing how much oil your can caught. And if there is an actual issue that needs to be addressed, i.e. excessive carbon deposits, then GM will address the issue. I would be surprised if they said to add a catch can though..

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How can it capture 99% of your air if it is only on one side of your engine? So let's pretend that it is actually effective in filtering oil. So now your driver's side intake valves are cleaner than your passenger side intake valves? How can this be beneficial? I think balance-wise, I would want both sides of the cylinders putting out the same levels of power...

 

I am interested in seeing your experiment results. Real proof of cleaner valves is more than just showing how much oil your can caught. And if there is an actual issue that needs to be addressed, i.e. excessive carbon deposits, then GM will address the issue. I would be surprised if they said to add a catch can though..

I think you need to read up again on airflow into your engine and what's going on with the PCV setup. In a nutshell, the air entering your engine comes predominantly from your air intake which is the filter box and tube connected to your throttle body. This is outside air and there's no oil in this air.

 

The PCV system is separate and works to relieve pressure in your crankcase by using the vacuum force of the intake to essentially suck the gases out of the crankcase. This is the hose that's connected to the port under your throttle body on the engine block and runs to either the side of the driver side valley cover on the 5.3 or the top of the throttle body on the 6.2L engine. This is the hose that contains the gases that are the source of nearly 99% of the oil ingested in the engine and it's in this line that the catch can is installed. Now we can debate the effectiveness of the catch can but regardless, the fact is this line contains most of the oil entering your engine and it's a very small percentage of the total volume of air going into your engine because again the intake is the primary source. It's not mixing with more oily air as you said it's mixing with a high amount of dry clean air from the intake.

 

The third source of air entering your engine are the two hoses that run from both valley covers to the airbox. This air is the smallest volume of air entering the engine and furthermore contains a very small percentage of oil or what we'll call the other 1% of oil entering the engine intake. A clean side separator works to take care of this last 1%.

 

so in theory, a catch can works to remove 99% of the oil ingested in the engine depending on the performance of the make/model can being used.

 

However you're correct we don't really have any before and after shots showing how effective it really is but there's a ton of info on the Internet that explains how a catch can works. I hope to have picture proof one way or the other in another year.

 

 

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How can it capture 99% of your air if it is only on one side of your engine? So let's pretend that it is actually effective in filtering oil. So now your driver's side intake valves are cleaner than your passenger side intake valves? How can this be beneficial? I think balance-wise, I would want both sides of the cylinders putting out the same levels of power...

 

I am interested in seeing your experiment results. Real proof of cleaner valves is more than just showing how much oil your can caught. And if there is an actual issue that needs to be addressed, i.e. excessive carbon deposits, then GM will address the issue. I would be surprised if they said to add a catch can though..

 

Wow, I'd say before you criticize people in this thread, you really need to understand how a PCV system works....and the intake system in general. Only one side of the engine? Cleaner valves on one side versus the other?

 

The PCV is just a pressure relief, the problem is that the air you are pulling from your crank case is full of vaporized oil and other hydrocarbons. When it's being introduced into your clean air intake stream, this exposes the valves on both sides of the engine to the oil vapours since it's a unified air intake stream...IE, one intake is feeding both sides of the engine, and you're introducing this dirty air flow to the main stream before it splits up.

 

From an engineering perspective, a catch can is good piece of mind because they are pulling oil that could have been introduced into the intake stream. This cannot be argued, and the visual evidence presented in these threads (and the threads across many other forums for many other manufacturers), demonstrate that the catch cans will collect significant amounts of oil that would have been otherwise introduced to the valves, cylinders and combustion cycle. Catch cans are not a snake oil product. They are a common feature on any air stream where you need the liquids/oils separated out in both automotive and industrial applications. Heck, every compressor I have at home and at my shop has a catch can to pull liquids out of the air. Keep in mind that many of our natural gas pipelines that are crossing the continent have filter/separators that are simply large catch cans on steroids.

 

Whether or not removing that oil will have a notifiable effect on the valve carbon build up is a source of many debates, but I'd rather be safe than sorry. As I don't have a direct injection engine, I can't show any evidence or experiences on my end that there is a impact on the valve buildup, but I am regularly emptying the crud out of my cans on a regular basis. I've also been running them on my vehicles for years now. I don't even run a fancy catch can, I constructed one myself using 1/2" fittings and an air compressor filter/separator, and it does a great job.

Edited by DanMan_S
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OK. My last post just showed my ignorance of PCV air flow. ? you guys came back with excellent explanations. Call me schooled! I was a tad buzzed and not thinking straight when I clacked out that last response! ?

 

However, it would still be hard to quantify exactly how much oil makes it to the cylinder intakes with and without the cans. I still doubt if carbon deposit rates are affected much. The proper experiment would be to take two identical engines, install a can on one, run them both identically and then tear them down to see the difference. But that is impractical.

Edited by spectaculous
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The technical term for what a "catch can" does is coalesce. The function is to remove liquids saturated into a flow of a gas.

Air Compressor systems have various methods to coalesce as do aircraft air conditioning/pressurization systems.

The simplest form of a coalescing device is an expansion type that allows the saturated gas to cool and slow. This allows the liquid vapor to form into droplets that stick to the chamber walls. These types are commonly seen for air compressor systems, with a clear bowl and drain valve. They are effective, but leave room for improvement.

When you add a type of baffle or labyrinth path for the gas to the above chamber, it increases the efficiency in removing liquid. The changes in direction allow inertia to force contact of droplets, formed from expansion, with the chamber walls. Centrifugal separators also rely on the inertia of the droplets to go to the outer wall because they are heavier than the gas. Centrifugal designs are difficult to make efficient with low flow rates.

Filter type coalescing systems are most often a combination of the above designs. They are almost always combined with expansion types. In many cases, labyrinth design is combined in at least a minimal way. Large airplanes use a type of filter, along with an expansion chamber to coalesce water out cabin air before it is sent to the cabin. The filter is simply a surface for the liquid droplets to adhere to. In these airplane a/c systems, it is a fabric stretched over a conical screen, in a larger cylindrical chamber (can). You often see a filter added to those "water separators " in compressor lines. This is not really for particulate removal, although it will do that. It is to provide more surface for droplets to adhere (coalesce).

The liquid in a crankcase vent flow will contain a significant amount of water vapor along with the oil vapor . This is condensation formed during cooling in the crankcase.

Edited by spurshot
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