oil catch can
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Joined: May 2004
Posts: 2,202
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From: San Fran
Seems like a lot of people don't know how to use the search.
If you want to do a search for a specific phrase you have to include quotation marks, ex.: "oil catch can"
Then it will search for that entire phrase. If you just do a search for oil catch can it will most likely give you a bunch of bogus links.
If you want to do a search for a specific phrase you have to include quotation marks, ex.: "oil catch can"
Then it will search for that entire phrase. If you just do a search for oil catch can it will most likely give you a bunch of bogus links.
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Joined: Jan 2004
Posts: 2,109
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search for oil catch can revealed MANY results here is a quote from a post by Naishou:
When a cylinder fires, some oil vapour, water vapour and other gunk is blown past the rings into the crankcase. In the old days this was vented to the air, but it's a pollutant. Nowadays legislation forces car makers to use Positive Crankcase Ventilation (PCV) which uses the pressure in the crankcase caused by blowby to redirect gases via a hose into the inlet, so they get burned again. The hose goes from the top of the valve cover to a place usually just after the throttle body. This is great if you have negative inlet pressure (inlet vacuum), but if you have a forced induction engine, you have a problem when under boost. To prevent inlet charge being blown into the crankcase, there is another connection (via a T-piece or similar) to a point before the turbo. Now when on boost the pressurised air will take this path instead and also create a little bit of vacuum in the part of the hose connected to the valve cover, helping to draw vapour out of the crankcase. The problem with this is that the oil vapour now goes through the intercooler and intake piping, condensing there. You can actually pour oil out of the intercooler on some high pressure turbo cars without a catch can. A catch can is a container that goes in the PCV line to filter and condense the vapour before it ends up in your intake. They are pretty much necessary on high pressure turbo engines, but on a NA engine the only point is to prevent the vapour getting into the cylinders again (it doesn't go into the intake hose on a NA car). This is bad because it reduces performance and effective fuel octane rating. However, unless it's got deliberately loose rings or is making a lot of power per litre, I don't think a NA car really needs one.
When a cylinder fires, some oil vapour, water vapour and other gunk is blown past the rings into the crankcase. In the old days this was vented to the air, but it's a pollutant. Nowadays legislation forces car makers to use Positive Crankcase Ventilation (PCV) which uses the pressure in the crankcase caused by blowby to redirect gases via a hose into the inlet, so they get burned again. The hose goes from the top of the valve cover to a place usually just after the throttle body. This is great if you have negative inlet pressure (inlet vacuum), but if you have a forced induction engine, you have a problem when under boost. To prevent inlet charge being blown into the crankcase, there is another connection (via a T-piece or similar) to a point before the turbo. Now when on boost the pressurised air will take this path instead and also create a little bit of vacuum in the part of the hose connected to the valve cover, helping to draw vapour out of the crankcase. The problem with this is that the oil vapour now goes through the intercooler and intake piping, condensing there. You can actually pour oil out of the intercooler on some high pressure turbo cars without a catch can. A catch can is a container that goes in the PCV line to filter and condense the vapour before it ends up in your intake. They are pretty much necessary on high pressure turbo engines, but on a NA engine the only point is to prevent the vapour getting into the cylinders again (it doesn't go into the intake hose on a NA car). This is bad because it reduces performance and effective fuel octane rating. However, unless it's got deliberately loose rings or is making a lot of power per litre, I don't think a NA car really needs one.
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Joined: May 2004
Posts: 2,202
Likes: 1
From: San Fran
This is my understanding of it:
In hard, high G corners (particularly right hand ones with this car) oil can make it's way up through the PCV valve and into the intake manifold where it's burned off once it gets into the cylinder. The solution for this is a catch can which does just that. It stores the oil blowby so the oil does not get into the intake manifold. Do a search for specifics.
In hard, high G corners (particularly right hand ones with this car) oil can make it's way up through the PCV valve and into the intake manifold where it's burned off once it gets into the cylinder. The solution for this is a catch can which does just that. It stores the oil blowby so the oil does not get into the intake manifold. Do a search for specifics.
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