Looks like I need a catch can. Which one to buy?
10-09-2009, 11:15 PM
#23
They do not all work the same as the internal design differs on so many. Think about it. If the inlet, and outlet, are1-2-3" from each other, the vapors drawn through do not have time to make complete contact with the external surface area to cool & condense, so all you are catching is the bigger particles and droplets already accumulating in the lines running to it. The rest, (fine mist & flashed off vapors & suspension) travels right on through and into the intake manifold (this is easy to document, just take a 3/8" clear fuel filter with the white media inside and put it inline just after the outlet on the can, run it for say 100-200 miles, and see if the media is saturated with oil or not. This is a good way to see just how effective each is (make sure it is the very same car driven the very same way during the tests). The smaller a can is, and the shorter the distance from the inlet to the outlet, the less effective it will be. Also, the internal design. Both the Saikou Michi & the RevX cans have a perforated disperssion tube that runs down the center from the inlet. This disperses the vapors/mists so they make contact with as much outer surface area as possible condensing nearly all the oil to droplets where they fall and collect at the bottom to be drained later through a bottom screw drain. The RevX adds an internal baffel disc between the outlet & the point the perforations begin to deflect the exiting vapors to outer surface area one last time & then has an integrated PCV/check valve in the outlet to regulate the amount of vacuum pulled & prevent any reversion or back-flow. The others shown & mentioned are real quality pieces and will trap a good amount as well, with the Mike Norris being the best largest (for cooling & condensing the vapors) IMHO out of the anodized billet ones as some of the others have just to short of a distance to the outlets from the inlet. The least of all as far as effectivness is the air compressore filter as it is plastic (does not conduct heat/cold very well), very small in capacity, and the inlet is only an inch or so from the outlet.
Remember. Even a beer can with 2 fittings poked into it will collect some oil, so this is an issue that affects most modern engines no matter what breed.
Remember. Even a beer can with 2 fittings poked into it will collect some oil, so this is an issue that affects most modern engines no matter what breed.
crappy thumbnailed link to picture - sorry i couldn't adjust the focus on my iphone.
having the air filter catch can is better than nothing, but i'll definitely go with the real deal after this.
10-10-2009, 07:22 AM
#24
i have a bit of oil in my husky air filter after about 500 hundred miles of driving, but you can see that a little oil is still getting through as can be seen lining the inner edge of this new pcv valve that was installed onto clean lines at the same time as my DIY catch can.
crappy thumbnailed link to picture - sorry i couldn't adjust the focus on my iphone.
having the air filter catch can is better than nothing, but i'll definitely go with the real deal after this.
crappy thumbnailed link to picture - sorry i couldn't adjust the focus on my iphone.
having the air filter catch can is better than nothing, but i'll definitely go with the real deal after this.
11-23-2009, 07:59 PM
#26
TECH Addict
www.conceptualpolymer.com if you want the best filtering. But you'll need to replace the filter in it with your oil and they're like $10 or $12. They work FAR better than anything else and do NOT get metal pieces into your engine like mesh-based filters.
12-17-2009, 07:21 PM
#27
www.conceptualpolymer.com if you want the best filtering. But you'll need to replace the filter in it with your oil and they're like $10 or $12. They work FAR better than anything else and do NOT get metal pieces into your engine like mesh-based filters.
Side by side testing of all including the CP unit show the Saikou Michi & RevX to be the most effective period although several of the other larger ones (Mike Norris, CCA, etc) not the small short ones work very well.
12-19-2009, 01:29 AM
#28
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...not quite.
As at least some catch can designers know, when it comes to wound filtration elements, anything less than 10 microns or so will allow particulates to clog up the element too quickly, resulting in an steadily decreasing vacuum pressure between the PCV valve and the filter. Once vacuum pressure drops 2.5-3 inches of mercury, crankcase pressure can increase enough to cause gasket leaks.
Stay away from Home Depot filters for a few reasons:
1. The polycarbonate body is rated to 125 degrees F. Blowby gases easily exceed 150F and engine bay temps (especially if LTs are installed) can soar past 160F.
2. The manufacturer of that polycarbonate body warns the user about exposing it to certain oils and fuels. Crazing of the plastic may occur and if the unit implodes, shards of plastic may find their way downstream.
3. A 5 micron filter will need to be replaced very often to avoid dangerously high crankcase pressures. This density of filter was designed for high positive pressure to assist air past the windings or perforations. Auto PCV systems never exceed 20" Hg, which is about 10 psi of negative pressure.
Also keep in mind that every catch can is a compromise in one way or another. Those that have no filter element and rely only on impaction and coalescence will never trap submicron and <5 micron oil droplets. This type of catch can, especially the giant versions, may be a good choice for racing, when extra-large amounts of blowby oil is produced, but for aggressive street driving and normal day-to-day driving, a filter element has the potential for catching more oil.
Catch cans with brillo pads (wound stainless steel fiber) are limited in their effectiveness by the diameter of the strands. The diameter must be large enough so that corrosion does not desinigrate the strands. Unfortunately, this means that very small droplets of oil will easily slip by the "mesh". In addition, loose strands may end up in the PCV line. Whether they make their way into the intake is not certain, but I for one will not take that chance.
The CP unit was not thrown together without research to verify its effectiveness. First, the 20 micron filter was chosen after tests using .5 to 10 micron filters showed that the tighter density of these filters allowed excessive clogging of the element to occur much too quickly. A 20 micron open cell structure was selected as a good, long-lasting element design. But that's not the only "filter" in the unit. The primary filter involves directing incoming blowby gasses out against the inner container wall, promoting coalescence when the hot gasses contact a cooler substrate. The gasses must also slam against a 90 degree bend twice. each added impaction releases a few more droplets from the airstream.
More info can be found in this article:
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
...one more thing I forgot to mention (although it is included in the article listed above) is that the PCV valve requires lubrication to operate properly. Never install it downstream of a filter. Oils contained in blowby gases are sufficient to lubricate the PCV valve adequately.
As at least some catch can designers know, when it comes to wound filtration elements, anything less than 10 microns or so will allow particulates to clog up the element too quickly, resulting in an steadily decreasing vacuum pressure between the PCV valve and the filter. Once vacuum pressure drops 2.5-3 inches of mercury, crankcase pressure can increase enough to cause gasket leaks.
Stay away from Home Depot filters for a few reasons:
1. The polycarbonate body is rated to 125 degrees F. Blowby gases easily exceed 150F and engine bay temps (especially if LTs are installed) can soar past 160F.
2. The manufacturer of that polycarbonate body warns the user about exposing it to certain oils and fuels. Crazing of the plastic may occur and if the unit implodes, shards of plastic may find their way downstream.
3. A 5 micron filter will need to be replaced very often to avoid dangerously high crankcase pressures. This density of filter was designed for high positive pressure to assist air past the windings or perforations. Auto PCV systems never exceed 20" Hg, which is about 10 psi of negative pressure.
Also keep in mind that every catch can is a compromise in one way or another. Those that have no filter element and rely only on impaction and coalescence will never trap submicron and <5 micron oil droplets. This type of catch can, especially the giant versions, may be a good choice for racing, when extra-large amounts of blowby oil is produced, but for aggressive street driving and normal day-to-day driving, a filter element has the potential for catching more oil.
Catch cans with brillo pads (wound stainless steel fiber) are limited in their effectiveness by the diameter of the strands. The diameter must be large enough so that corrosion does not desinigrate the strands. Unfortunately, this means that very small droplets of oil will easily slip by the "mesh". In addition, loose strands may end up in the PCV line. Whether they make their way into the intake is not certain, but I for one will not take that chance.
The CP unit was not thrown together without research to verify its effectiveness. First, the 20 micron filter was chosen after tests using .5 to 10 micron filters showed that the tighter density of these filters allowed excessive clogging of the element to occur much too quickly. A 20 micron open cell structure was selected as a good, long-lasting element design. But that's not the only "filter" in the unit. The primary filter involves directing incoming blowby gasses out against the inner container wall, promoting coalescence when the hot gasses contact a cooler substrate. The gasses must also slam against a 90 degree bend twice. each added impaction releases a few more droplets from the airstream.
More info can be found in this article:
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
...one more thing I forgot to mention (although it is included in the article listed above) is that the PCV valve requires lubrication to operate properly. Never install it downstream of a filter. Oils contained in blowby gases are sufficient to lubricate the PCV valve adequately.
Last edited by 01LS188; 12-19-2009 at 02:25 PM.
12-19-2009, 02:59 PM
#30
Although I had to wait for mine to arrive longer than I would have expected, I agree.
Reasonably priced, nice looking, and a cinch to install.
I have yet to put any miles on it. (Winter in Iowa seldom allows any F-body driving. At least my F-body.) But it seems to be doing the trick. I'll find out for sure this coming Spring.
Reasonably priced, nice looking, and a cinch to install.
I have yet to put any miles on it. (Winter in Iowa seldom allows any F-body driving. At least my F-body.) But it seems to be doing the trick. I'll find out for sure this coming Spring.
12-19-2009, 06:07 PM
#31
This is right from their website, and although much of the data quoted is correct, it does NOT work as good as the the two mentioned in side by side testing. The same filter is coalesing filter is availble for only a few dollars and although it DOES do a pretty good job,it is not as effective.
...not quite.
As at least some catch can designers know, when it comes to wound filtration elements, anything less than 10 microns or so will allow particulates to clog up the element too quickly, resulting in an steadily decreasing vacuum pressure between the PCV valve and the filter. Once vacuum pressure drops 2.5-3 inches of mercury, crankcase pressure can increase enough to cause gasket leaks.
Stay away from Home Depot filters for a few reasons:
1. The polycarbonate body is rated to 125 degrees F. Blowby gases easily exceed 150F and engine bay temps (especially if LTs are installed) can soar past 160F.
2. The manufacturer of that polycarbonate body warns the user about exposing it to certain oils and fuels. Crazing of the plastic may occur and if the unit implodes, shards of plastic may find their way downstream.
3. A 5 micron filter will need to be replaced very often to avoid dangerously high crankcase pressures. This density of filter was designed for high positive pressure to assist air past the windings or perforations. Auto PCV systems never exceed 20" Hg, which is about 10 psi of negative pressure.
Also keep in mind that every catch can is a compromise in one way or another. Those that have no filter element and rely only on impaction and coalescence will never trap submicron and <5 micron oil droplets. This type of catch can, especially the giant versions, may be a good choice for racing, when extra-large amounts of blowby oil is produced, but for aggressive street driving and normal day-to-day driving, a filter element has the potential for catching more oil.
Catch cans with brillo pads (wound stainless steel fiber) are limited in their effectiveness by the diameter of the strands. The diameter must be large enough so that corrosion does not desinigrate the strands. Unfortunately, this means that very small droplets of oil will easily slip by the "mesh". In addition, loose strands may end up in the PCV line. Whether they make their way into the intake is not certain, but I for one will not take that chance.
The CP unit was not thrown together without research to verify its effectiveness. First, the 20 micron filter was chosen after tests using .5 to 10 micron filters showed that the tighter density of these filters allowed excessive clogging of the element to occur much too quickly. A 20 micron open cell structure was selected as a good, long-lasting element design. But that's not the only "filter" in the unit. The primary filter involves directing incoming blowby gasses out against the inner container wall, promoting coalescence when the hot gasses contact a cooler substrate. The gasses must also slam against a 90 degree bend twice. each added impaction releases a few more droplets from the airstream.
More info can be found in this article:
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
...one more thing I forgot to mention (although it is included in the article listed above) is that the PCV valve requires lubrication to operate properly. Never install it downstream of a filter. Oils contained in blowby gases are sufficient to lubricate the PCV valve adequately.
As at least some catch can designers know, when it comes to wound filtration elements, anything less than 10 microns or so will allow particulates to clog up the element too quickly, resulting in an steadily decreasing vacuum pressure between the PCV valve and the filter. Once vacuum pressure drops 2.5-3 inches of mercury, crankcase pressure can increase enough to cause gasket leaks.
Stay away from Home Depot filters for a few reasons:
1. The polycarbonate body is rated to 125 degrees F. Blowby gases easily exceed 150F and engine bay temps (especially if LTs are installed) can soar past 160F.
2. The manufacturer of that polycarbonate body warns the user about exposing it to certain oils and fuels. Crazing of the plastic may occur and if the unit implodes, shards of plastic may find their way downstream.
3. A 5 micron filter will need to be replaced very often to avoid dangerously high crankcase pressures. This density of filter was designed for high positive pressure to assist air past the windings or perforations. Auto PCV systems never exceed 20" Hg, which is about 10 psi of negative pressure.
Also keep in mind that every catch can is a compromise in one way or another. Those that have no filter element and rely only on impaction and coalescence will never trap submicron and <5 micron oil droplets. This type of catch can, especially the giant versions, may be a good choice for racing, when extra-large amounts of blowby oil is produced, but for aggressive street driving and normal day-to-day driving, a filter element has the potential for catching more oil.
Catch cans with brillo pads (wound stainless steel fiber) are limited in their effectiveness by the diameter of the strands. The diameter must be large enough so that corrosion does not desinigrate the strands. Unfortunately, this means that very small droplets of oil will easily slip by the "mesh". In addition, loose strands may end up in the PCV line. Whether they make their way into the intake is not certain, but I for one will not take that chance.
The CP unit was not thrown together without research to verify its effectiveness. First, the 20 micron filter was chosen after tests using .5 to 10 micron filters showed that the tighter density of these filters allowed excessive clogging of the element to occur much too quickly. A 20 micron open cell structure was selected as a good, long-lasting element design. But that's not the only "filter" in the unit. The primary filter involves directing incoming blowby gasses out against the inner container wall, promoting coalescence when the hot gasses contact a cooler substrate. The gasses must also slam against a 90 degree bend twice. each added impaction releases a few more droplets from the airstream.
More info can be found in this article:
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
...one more thing I forgot to mention (although it is included in the article listed above) is that the PCV valve requires lubrication to operate properly. Never install it downstream of a filter. Oils contained in blowby gases are sufficient to lubricate the PCV valve adequately.
12-19-2009, 07:23 PM
#32
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True coalescing filters generally cost about $30 each, but as I mentioned, they were designed for much higher (positive) pressures. A 10% drop when pressure is 100 psi is not nearly as critical as a 10% drop when pressures barely reach -10 psi. In my own tests of many types of filters, some coalescing hybrids perform well initially, but tend to clog up more quickly than open cell particulate filters. Remember that coalescing filters were never meant as stand-alone filters due to their propensity to clog.
12-20-2009, 07:50 PM
#33
True coalescing filters generally cost about $30 each, but as I mentioned, they were designed for much higher (positive) pressures. A 10% drop when pressure is 100 psi is not nearly as critical as a 10% drop when pressures barely reach -10 psi. In my own tests of many types of filters, some coalescing hybrids perform well initially, but tend to clog up more quickly than open cell particulate filters. Remember that coalescing filters were never meant as stand-alone filters due to their propensity to clog.
12-20-2009, 08:21 PM
#34
I like the design of the RevXtreme catch can but with it's size I'm conserned about having a place for it on a C5 Vette. From what I understand you don't want to mount it on the front of the engine, it should be away from heat as much as possible. Does anyone have a pic of this can installed on a C5?
12-20-2009, 09:34 PM
#35
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12-21-2009, 09:54 AM
#36
I like the design of the RevXtreme catch can but with it's size I'm conserned about having a place for it on a C5 Vette. From what I understand you don't want to mount it on the front of the engine, it should be away from heat as much as possible. Does anyone have a pic of this can installed on a C5?
12-21-2009, 06:25 PM
#39
another question, I'm changing my LS1 valley to the LS6 valley that is off a '01 without the built in PVC. Would I need a PVC valve in-line from the catch can or will the one on the Rev X work? Also, do you a diagram of what I need to do to set this system up with the LS6 valley?
12-21-2009, 06:48 PM
#40
another question, I'm changing my LS1 valley to the LS6 valley that is off a '01 without the built in PVC. Would I need a PVC valve in-line from the catch can or will the one on the Rev X work? Also, do you a diagram of what I need to do to set this system up with the LS6 valley?
Give me your email address & I'll send you all the diagrams you could want.