Clearing up misconceptions with the PCV system
Drifting
Joined: Apr 2008
Posts: 1,955
Likes: 22
From: Lehigh Valley Pennsylvania
If one has done consistent oil analysis it is very easy to see the detrimental effects of a malfunctioning PCV system or vented crankcase evacuation system. I have quantitative oil analysis data showing the effects of a malfunctioning and poorly functioning PCV system derived from UOA's interpreted by one of the best tribologists in the industry. There are also many published studies quantifying the importance of PCV system functionality.
Concerning the quantity of crankcase blow by removed using a correctly vented crankcase evacuation system versus a correctly configured PCV system with an inline catch can, the above observation is not accurate.
A vented crankcase evacuation system will remove significantly less contaminates than a PCV system with an inline catch can. The PCV system with inline catch can has the huge advantage of intake manifold vacuum pulling blow by from the crankcase, increasing the efficiency of this configuration. The vented crankcase evacuation system relies on blow by to push contaminates out of the crankcase. This gives contaminates no where to go except to settle in the crankcase where it is absorbed by the engine oil and oil filtration system.
A cars use and oil change interval play a huge role in the scenarios. With all factors being identical, cars driven less at lower speeds using a vented crankcase evacuation system will see much higher oil contamination and engine wear levels than a car driven more often at higher speeds.
The typical street or mild race engine configuration LSx will maintain a slight vacuum in the intake manifold at WOT. At lower manifold vacuum conditions, i.e. WOT, blow by is typically at it highest level and PCV system flow capability is also at it's highest point. A slight vacuum during lower intake manifold vacuum conditions does produce enough DeltaP to pull high levels of blow by contamination from the crankcase when blow by production is at its highest. Using manifold vacuum to pull blow by from the crankcase greatly decreases crankcase pressure versus a vented system. Lower crankcase pressure demonstrates PCV system efficiency until the point of peak PCV system flow. If blow by production exceeds PCV system flow, crankcase pressure and engine oil contamination will occur.
Blow by contamination is detrimental to engine oil life and engine wear. Blow by is a mixture several gaseous, liquid, and particulate matter. The primary components of blow by are:
Engine oil type and oil filtration system are extremely important aspects of the equation. This is an ecosystem that's easily affected by small changes in other parts of the system. One must focus on the whole not just a part to observe the results. Here are a few things to think about:
A big misconception about any correctly configured PCV system is its ability to remove carry over oil from the PCV stream. There is not a device on the market today that will 100% eliminate carry over oil contamination from the PCV stream. The only methods currently available to 100% eliminate intake manifold carry over oil contamination are a completely vented crankcase system or vacuum pump.
I have looked at most of the catch cans currently available in the market and there are very few correctly designed. I know of two manufacturers that produce a high efficiency catch can and neither are supporting vendors here.
If you want to read many pages of good information about PCV systems, take a few hours and read these threads:
http://www.ls1tech.com/forums/genera...outing-ok.html
http://www.ls1tech.com/forums/genera...ls2-427-a.html
I am not associated with either of the vendors I recommend.
Concerning the quantity of crankcase blow by removed using a correctly vented crankcase evacuation system versus a correctly configured PCV system with an inline catch can, the above observation is not accurate.
A vented crankcase evacuation system will remove significantly less contaminates than a PCV system with an inline catch can. The PCV system with inline catch can has the huge advantage of intake manifold vacuum pulling blow by from the crankcase, increasing the efficiency of this configuration. The vented crankcase evacuation system relies on blow by to push contaminates out of the crankcase. This gives contaminates no where to go except to settle in the crankcase where it is absorbed by the engine oil and oil filtration system.
A cars use and oil change interval play a huge role in the scenarios. With all factors being identical, cars driven less at lower speeds using a vented crankcase evacuation system will see much higher oil contamination and engine wear levels than a car driven more often at higher speeds.
The typical street or mild race engine configuration LSx will maintain a slight vacuum in the intake manifold at WOT. At lower manifold vacuum conditions, i.e. WOT, blow by is typically at it highest level and PCV system flow capability is also at it's highest point. A slight vacuum during lower intake manifold vacuum conditions does produce enough DeltaP to pull high levels of blow by contamination from the crankcase when blow by production is at its highest. Using manifold vacuum to pull blow by from the crankcase greatly decreases crankcase pressure versus a vented system. Lower crankcase pressure demonstrates PCV system efficiency until the point of peak PCV system flow. If blow by production exceeds PCV system flow, crankcase pressure and engine oil contamination will occur.
Blow by contamination is detrimental to engine oil life and engine wear. Blow by is a mixture several gaseous, liquid, and particulate matter. The primary components of blow by are:
- Oil aerosol particles
- Soot particles
- Gasses
- Gaseous hydrocarbons
- Water vapor
- Aldehydes
- High insoluble percentages
- Reduced viscosity
- Reduced film strength
- High volatility
- Reduced detergency
- Higher oxidation
- Increased varnish production
- High acid formation
Engine oil type and oil filtration system are extremely important aspects of the equation. This is an ecosystem that's easily affected by small changes in other parts of the system. One must focus on the whole not just a part to observe the results. Here are a few things to think about:
- A poor tune that results in rich air/fuel ratios can increase the affects of a nonfunctional PCV system because of fuel dilution.
- A poor air filtration system will severely increase the impact of fuel dilution and poor PCV system function on engine wear.
- An inadequate oil filter will drastically increase engine wear from increased insoluble production caused by poor PCV system function.
- A good oil filter will become saturated very quickly by a poorly functioning PCV system.
A big misconception about any correctly configured PCV system is its ability to remove carry over oil from the PCV stream. There is not a device on the market today that will 100% eliminate carry over oil contamination from the PCV stream. The only methods currently available to 100% eliminate intake manifold carry over oil contamination are a completely vented crankcase system or vacuum pump.
I have looked at most of the catch cans currently available in the market and there are very few correctly designed. I know of two manufacturers that produce a high efficiency catch can and neither are supporting vendors here.
If you want to read many pages of good information about PCV systems, take a few hours and read these threads:
http://www.ls1tech.com/forums/genera...outing-ok.html
http://www.ls1tech.com/forums/genera...ls2-427-a.html
I am not associated with either of the vendors I recommend.
. I've been through this discussion 100 times, and once again, am yet to see any real data for either case and arguments are always theoretical. Please post the data you have access to, it would be interesting to see.
Here is the Wikipedia version of the reasons for the implementation of PCV systems for everyone's knowledge.
Prior to the early 1960s, automobile gasoline engines vented combustion gases directly to the atmosphere through a simple vent tube. Frequently this consisted of a pipe (the "road draft tube") that extended out from the crankcase down to the bottom of the engine compartment. The bottom of the pipe was open to the atmosphere, and was placed such that when the car was in motion a slight vacuum would be hopefully obtained, helping to extract combustion gases as they collected in the crankcase. The oil mist would also be discharged, resulting in an oily film being deposited in the middle of each travel lane on heavily-used roads. The system was not positive though, as gases could travel both ways, or not move at all, dependent on conditions. Most modern diesel engines still use this type of system to dispose of crankcase fumes. During World War II however, a different type of crankcase ventilation had to be invented to allow tank engines to operate during deep fording operations, where the normal draft tube ventilator would have allowed water to enter the crankcase and destroy the engine. The PCV system and its control valve were invented to meet this need but the need for it on automobiles was not recognized.
In 1952, Professor A. J. Haagen-Smit, of the California Institute of Technology at Pasadena, postulated that unburned hydrocarbons were a primary constituent of smog, and that gasoline powered automobiles were a major source of those hydrocarbons. After some investigation by the GM Research Laboratory (Dr. Lloyd L. Withrow) it was discovered in 1958 that the road draft tube was a major source, about half, of the hydrocarbons coming from the automobile. GM's Cadillac Division, which had built many tanks during WWII, recognized that the simple PCV valve could be used to become the first major reduction in automotive hydrocarbon emissions. After confirming the PCV valves' effectiveness at hydrocarbon reduction, GM offered the PCV solution to the entire U.S. automobile industry, royalty free, through its trade association, the Automobile Manufacturers Association (AMA). In the absence of any legislated requirement, the AMA members agreed to put it on all California cars voluntarily in the early 1960s, with national application following one year later.
Following its introduction into production, several years later the PCV became the subject of a Federal grand jury investigation in 1967, when it was alleged by some industry critics that the AMA was conspiring to keep several such smog reduction devices like the PCV on the shelf to delay smog control. After eighteen months of investigation by U.S. Attorney Samuel Flatow, the grand jury returned a "no-bill" decision, clearing the AMA, but resulting in a "Consent Decree" that all U.S. automobile companies agreed not to work jointly on smog control activities for a period of ten years.
Last edited by NormWild; Sep 21, 2009 at 08:44 AM.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
I am concerned that my oil looks dirtier now that I have the open system....
In addition to some scientific oil analysis data, it would be great if a trusted engine builder could chime in with some real world thoughts as to engines they've rebuilt with both types of systems, stock and open to atmosphere.
In addition to some scientific oil analysis data, it would be great if a trusted engine builder could chime in with some real world thoughts as to engines they've rebuilt with both types of systems, stock and open to atmosphere.
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
Got that in cliff notes?. I've been through this discussion 100 times, and once again, am yet to see any real data for either case and arguments are always theoretical. Please post the data you have access to, it would be interesting to see.
Here is the Wikipedia version of the reasons for the implementation of PCV systems for everyone's knowledge.
Prior to the early 1960s, automobile gasoline engines vented combustion gases directly to the atmosphere through a simple vent tube. Frequently this consisted of a pipe (the "road draft tube") that extended out from the crankcase down to the bottom of the engine compartment. The bottom of the pipe was open to the atmosphere, and was placed such that when the car was in motion a slight vacuum would be hopefully obtained, helping to extract combustion gases as they collected in the crankcase. The oil mist would also be discharged, resulting in an oily film being deposited in the middle of each travel lane on heavily-used roads. The system was not positive though, as gases could travel both ways, or not move at all, dependent on conditions. Most modern diesel engines still use this type of system to dispose of crankcase fumes. During World War II however, a different type of crankcase ventilation had to be invented to allow tank engines to operate during deep fording operations, where the normal draft tube ventilator would have allowed water to enter the crankcase and destroy the engine. The PCV system and its control valve were invented to meet this need but the need for it on automobiles was not recognized.
In 1952, Professor A. J. Haagen-Smit, of the California Institute of Technology at Pasadena, postulated that unburned hydrocarbons were a primary constituent of smog, and that gasoline powered automobiles were a major source of those hydrocarbons. After some investigation by the GM Research Laboratory (Dr. Lloyd L. Withrow) it was discovered in 1958 that the road draft tube was a major source, about half, of the hydrocarbons coming from the automobile. GM's Cadillac Division, which had built many tanks during WWII, recognized that the simple PCV valve could be used to become the first major reduction in automotive hydrocarbon emissions. After confirming the PCV valves' effectiveness at hydrocarbon reduction, GM offered the PCV solution to the entire U.S. automobile industry, royalty free, through its trade association, the Automobile Manufacturers Association (AMA). In the absence of any legislated requirement, the AMA members agreed to put it on all California cars voluntarily in the early 1960s, with national application following one year later.
Following its introduction into production, several years later the PCV became the subject of a Federal grand jury investigation in 1967, when it was alleged by some industry critics that the AMA was conspiring to keep several such smog reduction devices like the PCV on the shelf to delay smog control. After eighteen months of investigation by U.S. Attorney Samuel Flatow, the grand jury returned a "no-bill" decision, clearing the AMA, but resulting in a "Consent Decree" that all U.S. automobile companies agreed not to work jointly on smog control activities for a period of ten years.
. I've been through this discussion 100 times, and once again, am yet to see any real data for either case and arguments are always theoretical. Please post the data you have access to, it would be interesting to see.Here is the Wikipedia version of the reasons for the implementation of PCV systems for everyone's knowledge.
Prior to the early 1960s, automobile gasoline engines vented combustion gases directly to the atmosphere through a simple vent tube. Frequently this consisted of a pipe (the "road draft tube") that extended out from the crankcase down to the bottom of the engine compartment. The bottom of the pipe was open to the atmosphere, and was placed such that when the car was in motion a slight vacuum would be hopefully obtained, helping to extract combustion gases as they collected in the crankcase. The oil mist would also be discharged, resulting in an oily film being deposited in the middle of each travel lane on heavily-used roads. The system was not positive though, as gases could travel both ways, or not move at all, dependent on conditions. Most modern diesel engines still use this type of system to dispose of crankcase fumes. During World War II however, a different type of crankcase ventilation had to be invented to allow tank engines to operate during deep fording operations, where the normal draft tube ventilator would have allowed water to enter the crankcase and destroy the engine. The PCV system and its control valve were invented to meet this need but the need for it on automobiles was not recognized.
In 1952, Professor A. J. Haagen-Smit, of the California Institute of Technology at Pasadena, postulated that unburned hydrocarbons were a primary constituent of smog, and that gasoline powered automobiles were a major source of those hydrocarbons. After some investigation by the GM Research Laboratory (Dr. Lloyd L. Withrow) it was discovered in 1958 that the road draft tube was a major source, about half, of the hydrocarbons coming from the automobile. GM's Cadillac Division, which had built many tanks during WWII, recognized that the simple PCV valve could be used to become the first major reduction in automotive hydrocarbon emissions. After confirming the PCV valves' effectiveness at hydrocarbon reduction, GM offered the PCV solution to the entire U.S. automobile industry, royalty free, through its trade association, the Automobile Manufacturers Association (AMA). In the absence of any legislated requirement, the AMA members agreed to put it on all California cars voluntarily in the early 1960s, with national application following one year later.
Following its introduction into production, several years later the PCV became the subject of a Federal grand jury investigation in 1967, when it was alleged by some industry critics that the AMA was conspiring to keep several such smog reduction devices like the PCV on the shelf to delay smog control. After eighteen months of investigation by U.S. Attorney Samuel Flatow, the grand jury returned a "no-bill" decision, clearing the AMA, but resulting in a "Consent Decree" that all U.S. automobile companies agreed not to work jointly on smog control activities for a period of ten years.
I'm not being a *****, just protective of my data. Like I stated above, there are many studies on this subject, but none are free. You'll have to pay for their research or pay for your own to see the data.
The wikipedia information is okay for recreational reading, but it only covers a very narrow aspect of the total subject.
Last edited by thetorch; Sep 21, 2009 at 11:45 AM.
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
I am concerned that my oil looks dirtier now that I have the open system....
In addition to some scientific oil analysis data, it would be great if a trusted engine builder could chime in with some real world thoughts as to engines they've rebuilt with both types of systems, stock and open to atmosphere.
In addition to some scientific oil analysis data, it would be great if a trusted engine builder could chime in with some real world thoughts as to engines they've rebuilt with both types of systems, stock and open to atmosphere.
At the very least drag only motors have a scavange evac system in the header colletors to pull vac, and anyone thats serious has a belt driven vac pump.....especially the Alky motors due to the amount of moisture the alchol introduces to the crankcase. Next time your at a sanctioned )NHRA/IHRA) race walk around the pits and look at the dragster motors and how they evac. You will see that any w/a vac pump run a relief valve on the opposite valve cover because if you pul any more than 14-15" of vac you start to pull oil off the wrist pins & rod journals.
I have run a pro team for 7 years and we run most every sanctioned track in the Eastern US and have yet to see a high HP dragster or door car w/out evac so I'm curious to what class they race and where.
The oil analysis will show the acid build up....and no, it takes a year or two before you would see any substantial damage to your internal engine parts.....but an easy way is after 6 mnths or so of runninng like you describe pull a valve cover and look and the corrosion from the vapors on your rocker arms. This is the first place it is visable.
More of my background? My team holds several local, divisonal, National, & World championships in Super Pro, Super Comp, Quickrod, Top Dragster, and non-electronics.....I am also a graduate of the Reher Morrision Racing engine building school and have been an engine builder for over 35 years. Take a little time & read David Reher's tech tips......a world of information: http://www.rehermorrison.com/blog/?cat=3
Bottom line is, w/out a proper evac system you WILL sustain long term engine damage. It may take a few years to notice, but I build motors 6 days a week when not racing and see the results first hand.
Can you send me pics of how the can was set-up? If plumbed correctly, and the oil is coming into the intake from the PCV then the can will catch all but a very small amount (no can can catch 100%). It is also possible if you have an early design (over 8 months old) that the perforated dispersion tube may have come loose so the vapors are going in the top and right out the outlet instead of down the tube and dispersed to condense to droplets that are trapped...just send it back & they will repair & update it free). There are several other ways for oil mist to enter the intake manifold, the PCV system is the most common with the fresh air make up source (the fitting on the top rear of your throttle body) being the second most common. To eliminate that you need to cap the TB fitting and run a valve cover breather (installed as far from the crankcase vent as possible...ideally you want to pull filtered fresh air in one valve cover & evac it out the other or the LS6/LS2 style valley cover is sencond best) Then if it is excess crankcase pressure pushing oil vapor/mist out faster than the PCV can evac it you will see it pushed back through the line from the pass valve cover front to the TB and it is ingested from there. The 3rd point of ingestion is from reversion. This of course needs at least one piston/ring/bore/valveguide or seal issue that is allowing oil to be pulled into that one or more intake port and at high RPM's the reversion pulse will "push" that oil throughout the entire intake manifold. It will appear to have entered from the vac fitting that the PCV system uses but is really from one of the cylinders (reversion is a whole different process that is not widely understood but do a Google search and you can actually find some super high speed video of engines on dyno's where at high RPM's...9-10-12K plus the reversion cloud of A/F mixture is actually rising out of the intake runners or carb on a non fuel injected motor). To test for that just place a clean clear fuel filter inline between the catch can outlet (the side fitting on the RevX can) and the vac fitting. If it gets oil on the can side, oil is coming through the can. If it first appears on the intake vacuum side, then it is reversion so you have a deeper issue. On the LS motors we pull apart it is usually # 7 ringland broken between the compression & middle ring, or the land itself broke off at the top. We also find the top ringland pinched or crushed down on the top ring (comp. ring) and metal transfer along the piston side has caused the oil & scraper ring to stick allowing oil & blow-by. Also, try this: at idle (vac is at it's greatest when at idle or when the throttle blade closes from high RPM's) remove the oil fill cap and hold your hand over it. Does it pull a slight suction? If so, all is good with most of the system and I doubt you have a damaged piston/ring/bore. But if there is ANY pressure pushing back you have a deeper issue and that is the cause of the oil problem.
Now on big cam/stroker builds a can inline on the dirty side, and a can inline from the fresh air source may be needed (the bigger the bore & longer the stroke, the more crankcase pressure is built up) If it is forced induction, then you have a whole new process to deal with......and that is the PCV system works proerly when at idle & non-boost, but when you start making boost you have switched from the intake manifold being negative atmosphere to a pressurized component and the PCV system is rendered useless and pressure escapes wherever it can. The solution then is to have oneway check valves inline so the vacuum need for proper evacuation comes from in front of the compressor (head unit) through a line run to the air filter.
This is getting a bit long and I hope all can follow this, but if not ask me specific questions for clarification so this helps all. I'll go over every type of solution and the pros & cons of each....and remeber, this problem is NOT just in the GM LS based engines, but is an issue with ALL modern closed systems. We just tear into our cars where as the Mercedes or Lincoln owner never even realizes there is an issue.
I also wanted to address the water in the oil. You will NOT fill your crankcase up in short order with just breathers. What happens is each time your engine reaches operating temp the unburnt fuel, water vapor, combustion by-products will gass or "flash-off" as vapor. But only the excess crankcase pressure being relieved through the breather will carry any of that out....and without a proper evac system, a good amount remains in the crankcase and recondenses back to droplets that coat the internal engine parts as your motor cools down and it contaminates the oil. Every time you heat cycle you are adding more contamination and it is not very visable to just "look" at your oil....you need a proffesional analysis to see just what is accumulating in your oil and how it is breaking down its ability to protect...but the corrosion from the sulferic acid is also very damaging over time (I'll try to post up some pics of parts showing just this in the near future). Just pull the dipstick on a diesel 20 miles after an oil change...it already "looks" black & dirty, but is still new and providing the proper protection. Sight is deceiving. Oil might look pretty clean or dirty but an analysis report will show destructive levels of contaminants.
Drifting
Joined: Apr 2008
Posts: 1,955
Likes: 22
From: Lehigh Valley Pennsylvania
May I suggest that if you want to find the real answer rather than discuss it a few more times, you do the testing/research yourself. It takes a significant amount of money and time to perform this testing and since I've done it all on my dime I'm hesitant to give away the investment. I'll offer my opinion based on my testing but that's where I draw the line.
I'm not being a *****, just protective of my data. Like I stated above, there are many studies on this subject, but none are free. You'll have to pay for their research or pay for your own to see the data.
The wikipedia information is okay for recreational reading, but it only covers a very narrow aspect of the total subject.
I'm not being a *****, just protective of my data. Like I stated above, there are many studies on this subject, but none are free. You'll have to pay for their research or pay for your own to see the data.
The wikipedia information is okay for recreational reading, but it only covers a very narrow aspect of the total subject.
Unsubscribed to another intriguing and fact filled PCV discussion thread. Thanks for your, um, input.
Last edited by NormWild; Sep 21, 2009 at 08:13 PM.
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
I hope you find free information your looking for. I'm sure you have vendors beating down the door to give you free parts and services.
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Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
First I want to thank everyone for their contributions to this thread. All the discussion and information I find extremely valuable. I am learning a great deal. I modified my PCV system (C6 - LS2) to that of a breather can in May of this year when installing my SpinFAST. I am now concerned that eliminating the Catch Can will lead to bigger problems than my concerns of oil vapor ingestion.
Will running two Catch Cans in series do a better job of eliminating oil ingestion than a single Catch Can or is this just a waste of effort and money? Which Catch Can does the best job of reducing the ingestion of oil (oil vapor)?
Will running two Catch Cans in series do a better job of eliminating oil ingestion than a single Catch Can or is this just a waste of effort and money? Which Catch Can does the best job of reducing the ingestion of oil (oil vapor)?
Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
Which Catch Can is most effective in reducing the amount of oil vapor returned to the intake manifold?
Will Catch Can's in series help with this problem or does the law of diminishing returns rule here?
Will Catch Can's in series help with this problem or does the law of diminishing returns rule here?
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
I have never ran cans in series and I'm sure it would help some, but I wouldn't bother. If your going to run two cans, put one on the clean side and one on the dirty side.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
Torch and Tracy, thanks for this information and taking the time to type it.
I am convinced. This makes inherent sense to me and I trust your word that it is scientifically proven.
I'll call tomorrow Tracy to order a can. Same number as above?
I am convinced. This makes inherent sense to me and I trust your word that it is scientifically proven.
I'll call tomorrow Tracy to order a can. Same number as above?
Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
Aaron, thanks for your input and suggestions. I will change the plumbing of my C6 LS2 to again take advantage of my Elite Engineering Catch Can. I will also purchase the RevXtreme Catch Can and plan to use the Elite Can on the fresh air side and the RevXtreme Can on the dirty air side.
Can anyone tell me how the RevXtreme Can differs from Elite's Can. Is one more efficient than the other or is the difference so small its of no consequence?
Can anyone tell me how the RevXtreme Can differs from Elite's Can. Is one more efficient than the other or is the difference so small its of no consequence?
Melting Slicks
Joined: Mar 2007
Posts: 2,002
Likes: 2
From: Carlsbad CA
Okay, I read this whole thread. I was amazed when I discoverd this thing started so long ago and just came back! The discussion is quite frankly over my head. More technical information than I need. I have what I hope is a simple question .... I have an Elite Catch Can, if hooked up the way the manufacture instructs, am I doing good or is it a waste?
I removed it a year or so ago because it is such a PIA to drain but I will put it back on for sure if it truely is beneficial.
Thanks
I removed it a year or so ago because it is such a PIA to drain but I will put it back on for sure if it truely is beneficial.
Thanks
Pro
Joined: Jul 2006
Posts: 608
Likes: 1
From: LZ IL
What I wonder is the clean air side ,which at idle, is flowing toward the pass side valve cover. At WOT has to flow toward the bellows in front of the TB right? I would think this would cause more oil ingestion than the dirty side at idle. Does the clean side vent the engine during WOT? How can it not with that line being in front of the throttle valve? What prevents it from sucking everything out that valve cover?
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 231
From: SoCal
Okay, I read this whole thread. I was amazed when I discoverd this thing started so long ago and just came back! The discussion is quite frankly over my head. More technical information than I need. I have what I hope is a simple question .... I have an Elite Catch Can, if hooked up the way the manufacture instructs, am I doing good or is it a waste?
I removed it a year or so ago because it is such a PIA to drain but I will put it back on for sure if it truely is beneficial.
Thanks
I removed it a year or so ago because it is such a PIA to drain but I will put it back on for sure if it truely is beneficial.
Thanks
You will see for your self how much oil you catch. Different cars and drivers, street or track/canyons will vary the amount caught. But it can't hurt .... any oil it catches is oil not going were you don't want it
DH
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
Aaron, thanks for your input and suggestions. I will change the plumbing of my C6 LS2 to again take advantage of my Elite Engineering Catch Can. I will also purchase the RevXtreme Catch Can and plan to use the Elite Can on the fresh air side and the RevXtreme Can on the dirty air side.
Can anyone tell me how the RevXtreme Can differs from Elite's Can. Is one more efficient than the other or is the difference so small its of no consequence?
Can anyone tell me how the RevXtreme Can differs from Elite's Can. Is one more efficient than the other or is the difference so small its of no consequence?
Diameter and length are calculated minimum outputs from given engine parameters for catch can size. It's very important to maintain these minimums as it significantly contributes to the overall effectiveness of the can by allowing gravity time to do it's job in the separation process. For carry over oil to drop out of suspension, PCV system flow must slow to a minimum of 1 meter per second and maintain this flow rate for as long as possible. This allows gravity to help the process because heavy oil particulate matter falls out of suspension and pools in the can.
Internal design separates the good from the bad. There are many ancillary methods employed in catch can design to aid carry over oil removal. The RevX can uses a long dispersion tube with vent holes running the length of the can and a black flow restricter disk in the upper one third. The EE can uses media and a diffuser in the top to help condensation. Media does well when it's dry, but becomes saturated quickly where it no longer catches oil droplets. The diffuser can be effective but it's too far up in the design to work effectively. This is not to say the EE can won't catch anything. The internal design isn't the best.
Originally Posted by oneblackvette
What I wonder is the clean air side ,which at idle, is flowing toward the pass side valve cover. At WOT has to flow toward the bellows in front of the TB right? I would think this would cause more oil ingestion than the dirty side at idle. Does the clean side vent the engine during WOT? How can it not with that line being in front of the throttle valve? What prevents it from sucking everything out that valve cover?
At WOT the clean side SHOULD still flow into the engine and only reverse if dirty side flow is restricted or has reached capacity. On LSx engines, the top end holds oil making clean side reversion even easier. Autocross and road course cars will frequently see clean side reversion.
Hinson Supercars is a supporting vendor that sells the RevX can.
HTH,
Last edited by thetorch; Sep 24, 2009 at 11:02 PM.
Safety Car
Joined: Aug 2006
Posts: 4,347
Likes: 25
From: Apache Junction AZ
The RevX and EE can differ in size and internal design. Both are important factors in the design of an efficient catch can.
Diameter and length are calculated minimum outputs from given engine parameters for catch can size. It's very important to maintain these minimums as it significantly contributes to the overall effectiveness of the can by allowing gravity time to do it's job in the separation process. For carry over oil to drop out of suspension, PCV system flow must slow to a minimum of 1 meter per second and maintain this flow rate for as long as possible. This allows gravity to help the process because heavy oil particulate matter falls out of suspension and pools in the can.
Internal design separates the good from the bad. There are many ancillary methods employed in catch can design to aid carry over oil removal. The RevX can uses a long dispersion tube with vent holes running the length of the can and a black flow restricter disk in the upper one third. The EE can uses media and a diffuser in the top to help condensation. Media does well when it's dry, but becomes saturated quickly where it no longer catches oil droplets. The diffuser can be effective but it's too far up in the design to work effectively. This is not to say the EE can won't catch anything. The internal design isn't the best.
The clean side is designed to be the air clean air input path for the PCV system, but since the LSx PCV systems don't have flow path directors each side can flow either direction based on engine running condition.
At WOT the clean side SHOULD still flow into the engine and only reverse if dirty side flow is restricted or has reached capacity. On LSx engines, the top end holds oil making clean side reversion even easier. Autocross and road course cars will frequently see clean side reversion.
Hinson Supercars is a supporting vendor that sells the RevX can.
HTH,
Diameter and length are calculated minimum outputs from given engine parameters for catch can size. It's very important to maintain these minimums as it significantly contributes to the overall effectiveness of the can by allowing gravity time to do it's job in the separation process. For carry over oil to drop out of suspension, PCV system flow must slow to a minimum of 1 meter per second and maintain this flow rate for as long as possible. This allows gravity to help the process because heavy oil particulate matter falls out of suspension and pools in the can.
Internal design separates the good from the bad. There are many ancillary methods employed in catch can design to aid carry over oil removal. The RevX can uses a long dispersion tube with vent holes running the length of the can and a black flow restricter disk in the upper one third. The EE can uses media and a diffuser in the top to help condensation. Media does well when it's dry, but becomes saturated quickly where it no longer catches oil droplets. The diffuser can be effective but it's too far up in the design to work effectively. This is not to say the EE can won't catch anything. The internal design isn't the best.
The clean side is designed to be the air clean air input path for the PCV system, but since the LSx PCV systems don't have flow path directors each side can flow either direction based on engine running condition.
At WOT the clean side SHOULD still flow into the engine and only reverse if dirty side flow is restricted or has reached capacity. On LSx engines, the top end holds oil making clean side reversion even easier. Autocross and road course cars will frequently see clean side reversion.
Hinson Supercars is a supporting vendor that sells the RevX can.
HTH,
BJK
Burning Brakes
Joined: Jul 2000
Posts: 1,134
Likes: 1
From: Arlington Texas
You may want to call, I couldn't find it on their website.
If your running forced induction, you will need to configure the PCV system a little differently. Please post your specific engine configuration and detailed PCV configuration to ensure the can will be plumbed correctly.
Last edited by thetorch; Sep 24, 2009 at 01:04 PM.
Safety Car
Joined: Aug 2006
Posts: 4,347
Likes: 25
From: Apache Junction AZ
http://www.hinsonsupercars.com/default.aspx
You may want to call, I couldn't find it on their website.
If your running forced induction, you will need to configure the PCV system a little differently. Please post your specific engine configuration and detailed PCV configuration to ensure the can will be plumbed correctly.
You may want to call, I couldn't find it on their website.
If your running forced induction, you will need to configure the PCV system a little differently. Please post your specific engine configuration and detailed PCV configuration to ensure the can will be plumbed correctly.
BJK