My catch can routing ok?
01-25-2009, 08:06 AM
#1
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My catch can routing ok? Fitted this catch can on my set up, is this routing ok? I have blanked all of the ones on the FAST intake and these two pipes are the only vents ( apart from servo ) , the cap on the tank is a vent with a gauze filter, but you can see mist coming out of it still. The can is empty so was thinking i might shove some gauze in that too.
01-25-2009, 11:35 AM
#5
So is fresh air coming in from the vent on the catch can and going to the engine at the passenger side valve cover? If so, then you are pulling in unmetered air. If not, you need to supply a fresh air source to go back to the engine and it needs to be after the maf.
01-25-2009, 12:45 PM
#6
The PCV system has two main parts. 1) the clean air side, 2) the dirty air side. The clean air side connects from the valve cover to a clean air source after the MAF and only routes through a catch can IF you have two separate cans installed. The dirty side connects from the valley cover or drivers side valve cover (depending on which configuration you have) through an inline PCV valve to the catch can and then back to the intake manifold.
Your PCV system should be closed. Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.
The intent of the PCV system is to reduce crankcase pressure manifested from blow-by during the engine cycle. Engine vacuum is much more efficient at drawing these gases out of the crankcase than venting to atmosphere. This also creates a small vacuum on the crankcase that does slightly improve ring seal and power output. The final benefit is the environment. A closed PCV system recirculates the blow-by gases rather than releasing them in the atmosphere.
Concerning the construction of catch cans; the internal construction is critical. If the can is empty, it's not doing anything to catch the vaporized fluids from the crankcase. In fact, there are very few catch cans with an effective internal design to function properly. Check out this link: http://www.saikoumichi.com/OCC_explanation.htm This is how an effective catch can is designed internally.
Here's a mark up on your picture of my recommendation. If you road race the car, I would recommend two SEPARATE catch cans connected to each the clean and dirty sides of the PCV system.
Here is how I have mine routed. I have two separate catch cans connected as I state above.
Your PCV system should be closed. Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.
The intent of the PCV system is to reduce crankcase pressure manifested from blow-by during the engine cycle. Engine vacuum is much more efficient at drawing these gases out of the crankcase than venting to atmosphere. This also creates a small vacuum on the crankcase that does slightly improve ring seal and power output. The final benefit is the environment. A closed PCV system recirculates the blow-by gases rather than releasing them in the atmosphere.
Concerning the construction of catch cans; the internal construction is critical. If the can is empty, it's not doing anything to catch the vaporized fluids from the crankcase. In fact, there are very few catch cans with an effective internal design to function properly. Check out this link: http://www.saikoumichi.com/OCC_explanation.htm This is how an effective catch can is designed internally.
Here's a mark up on your picture of my recommendation. If you road race the car, I would recommend two SEPARATE catch cans connected to each the clean and dirty sides of the PCV system.
Here is how I have mine routed. I have two separate catch cans connected as I state above.
Last edited by 405HP_Z06; 01-26-2009 at 12:05 AM.
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HillWilly (02-23-2023)
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01-25-2009, 07:13 PM
#10
From my experience, when I'm street driving the dirty side catches most of the oil vapor. During HPDE weekends, the clean air side usually catches just as much or more than the dirty side. This is why I run two separate catch cans.
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Homer_Simpson (08-06-2023)
01-25-2009, 07:23 PM
#11
So, are you are saying during road racing the top of the engine becomes loaded with oil and back travels through the valve cover to the clean catch can to the TB and into the intake? Which is the only way for the clean side can to come in contact with oil to begin with.
From my experience, the second catch can on the clean air side is needed when road racing the car. For normal street driving, the dirty side catch can is adequate to catch most air born vapor (assuming the catch can is designed correctly). However, during road racing the top end of the engine becomes loaded with oil causing the clean air side to ingest oil into the intake.
From my experience, when I'm street driving the dirty side catches most of the oil vapor. During HPDE weekends, the clean air side usually catches just as much or more than the dirty side. This is why I run two separate catch cans.
From my experience, when I'm street driving the dirty side catches most of the oil vapor. During HPDE weekends, the clean air side usually catches just as much or more than the dirty side. This is why I run two separate catch cans.
01-25-2009, 07:33 PM
#12
So, are you are saying during road racing the top of the engine becomes loaded with oil and back travels through the valve cover to the clean catch can to the TB and into the intake? Which is the only way for the clean side can to come in contact with oil to begin with.
With the catch can I no longer have this problem. The catch can prevents oil ingestion through this port.
01-26-2009, 11:42 AM
#16
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So if you have 2 cans just cut the green hose and run the hose from the valve cover to the top of the can and the lower hose back to the throttle body? How do you clean them? Will this work on a car with forced induction?
01-26-2009, 12:53 PM
#17
The PCV system has two main parts. 1) the clean air side, 2) the dirty air side. The clean air side connects from the valve cover to a clean air source after the MAF and only routes through a catch can IF you have two separate cans installed. The dirty side connects from the valley cover or drivers side valve cover (depending on which configuration you have) through an inline PCV valve to the catch can and then back to the intake manifold.
Your PCV system should be closed. Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.
The intent of the PCV system is to reduce crankcase pressure manifested from blow-by during the engine cycle. Engine vacuum is much more efficient at drawing these gases out of the crankcase than venting to atmosphere. This also creates a small vacuum on the crankcase that does slightly improve ring seal and power output. The final benefit is the environment. A closed PCV system recirculates the blow-by gases rather than releasing them in the atmosphere.
Concerning the construction of catch cans; the internal construction is critical. If the can is empty, it's not doing anything to catch the vaporized fluids from the crankcase. In fact, there are very few catch cans with an effective internal design to function properly. Check out this link: http://www.saikoumichi.com/OCC_explanation.htm This is how an effective catch can is designed internally.
Here's a mark up on your picture of my recommendation. If you road race the car, I would recommend two SEPARATE catch cans connected to each the clean and dirty sides of the PCV system.
Here is how I have mine routed. I have two separate catch cans connected as I state above.
Your PCV system should be closed. Do not use a breather on the catch can or valve cover as it allows for unmetered air to enter the engine and makes the PCV system function improperly and less efficiently.
The intent of the PCV system is to reduce crankcase pressure manifested from blow-by during the engine cycle. Engine vacuum is much more efficient at drawing these gases out of the crankcase than venting to atmosphere. This also creates a small vacuum on the crankcase that does slightly improve ring seal and power output. The final benefit is the environment. A closed PCV system recirculates the blow-by gases rather than releasing them in the atmosphere.
Concerning the construction of catch cans; the internal construction is critical. If the can is empty, it's not doing anything to catch the vaporized fluids from the crankcase. In fact, there are very few catch cans with an effective internal design to function properly. Check out this link: http://www.saikoumichi.com/OCC_explanation.htm This is how an effective catch can is designed internally.
Here's a mark up on your picture of my recommendation. If you road race the car, I would recommend two SEPARATE catch cans connected to each the clean and dirty sides of the PCV system.
Here is how I have mine routed. I have two separate catch cans connected as I state above.
Good info, but the PCV sytem does far more than just release excess crankcase pressure. On a street engine, the proper PCV system keeps a clean air flow through the crankcase that removes the moisture, unburnt fuel, and corrosive combustion by-products (Sulferic acid being just one) that "flash-off" during operating temps....and without a "flush" through the crankcase will re-condense back onto the internal parts & engine oil causing extensive damage over time. The proper catchcan does need to be prperly designed inside to #1, catch-cool& condense the oil mist/vapors into droplets and have a baffel system to trap them so they are not pulled through into the vacume source (intake manifold), and to properly cool enough to condense all possible a 1 qt design (or 2 1 pint smaller ones) is the minimum for a street driven car. On road track cars 1/2 gal seems to be the ticket.
Also, the OEM set-up draws filtered fresh air from the front of the TB, and it is adequate, but allows for oil mist to enter the intake via this connection through reversion pulses....and therefore a filtered oil fill cap eliminates this and if tuned with the breathered cap there are no metering issues.
Most mistake a PCV system for only releiving crankcase pressure, an important function, but it has an equally important function and that is to save your engine!!!
On track/drag applications a vacume pump is used to pull these out or a venturi style evac set-up into the header collectors works as well, but oil is changed every few races so the same issues a street car faces are avoided.
As far as the most functional design on the market, any with a mesh filter material will do a great job intially, until the material becomes saturated and then you will see droplets pulling off the mesh and getting into the intake. (Not a tone, but still some) thousands of mine are in use and have been tested side-by-side with most everyone on the market and have yet to find one as efficient. For a supporting vendor I would reccomend Mike Norris's using 2 in series.
01-26-2009, 09:43 PM
#18
Good info, but the PCV sytem does far more than just release excess crankcase pressure. On a street engine, the proper PCV system keeps a clean air flow through the crankcase that removes the moisture, unburnt fuel, and corrosive combustion by-products (Sulferic acid being just one) that "flash-off" during operating temps....and without a "flush" through the crankcase will re-condense back onto the internal parts & engine oil causing extensive damage over time. The proper catchcan does need to be prperly designed inside to #1, catch-cool& condense the oil mist/vapors into droplets and have a baffel system to trap them so they are not pulled through into the vacume source (intake manifold), and to properly cool enough to condense all possible a 1 qt design (or 2 1 pint smaller ones) is the minimum for a street driven car. On road track cars 1/2 gal seems to be the ticket.
Also, the OEM set-up draws filtered fresh air from the front of the TB, and it is adequate, but allows for oil mist to enter the intake via this connection through reversion pulses....and therefore a filtered oil fill cap eliminates this and if tuned with the breathered cap there are no metering issues.
Most mistake a PCV system for only releiving crankcase pressure, an important function, but it has an equally important function and that is to save your engine!!!
On track/drag applications a vacume pump is used to pull these out or a venturi style evac set-up into the header collectors works as well, but oil is changed every few races so the same issues a street car faces are avoided.
As far as the most functional design on the market, any with a mesh filter material will do a great job intially, until the material becomes saturated and then you will see droplets pulling off the mesh and getting into the intake. (Not a tone, but still some) thousands of mine are in use and have been tested side-by-side with most everyone on the market and have yet to find one as efficient. For a supporting vendor I would reccomend Mike Norris's using 2 in series.
Also, the OEM set-up draws filtered fresh air from the front of the TB, and it is adequate, but allows for oil mist to enter the intake via this connection through reversion pulses....and therefore a filtered oil fill cap eliminates this and if tuned with the breathered cap there are no metering issues.
Most mistake a PCV system for only releiving crankcase pressure, an important function, but it has an equally important function and that is to save your engine!!!
On track/drag applications a vacume pump is used to pull these out or a venturi style evac set-up into the header collectors works as well, but oil is changed every few races so the same issues a street car faces are avoided.
As far as the most functional design on the market, any with a mesh filter material will do a great job intially, until the material becomes saturated and then you will see droplets pulling off the mesh and getting into the intake. (Not a tone, but still some) thousands of mine are in use and have been tested side-by-side with most everyone on the market and have yet to find one as efficient. For a supporting vendor I would reccomend Mike Norris's using 2 in series.
I didn't mention the aspect you state above because you can't do one without the other. I use oil analysis to monitor contamination levels associated with engine oil. I haven't seen any difference in analysis results comparing results before and after the catch can so it's my hypothesis the PCV system was and still is functioning correctly. I disagree with venting the crankcase. This reduces the efficiency of the PCV system by introducing a large pressure drop that would normally be a constant slight vacuum. Short of a highly efficient coalescing filter pared with a vacuum pump configuration, it's impossible to completely eliminate all oil vapor from the PCV system. A little (hard to define) is okay, IMHO. Typically, if venting to atmosphere seems to help the PCV system it's because the flow through the clean and dirty sides is not adequate. A can with larger ports and larger ports on the rest of the system will typically cure this problem.
I've never used yours or seen the interior design of your catch can so I can't comment on it's specific effectiveness. I can say that most of the cans I've seen here and on other boards are a joke.
01-26-2009, 09:54 PM
#19
See Post: https://ls1tech.com/forums/11059703-post70.html for diagrams.
Last edited by 405HP_Z06; 03-04-2009 at 12:17 AM.
