Catch can
03-11-2005, 07:58 PM
#3
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On a normal piston engine when intake system is not under pressure (ie a shift), a small amount of engine oil escapes into the intake track. This is a very small amount, but over time it adds up. A catch can catches this extra amount of oil. This is why if you've ever inspected your intake you'll find a small residue of oil all over.
Now, on a rotary I don't know if this is true, as I am new to them. Anyone else know more specifically?
Trevor
Now, on a rotary I don't know if this is true, as I am new to them. Anyone else know more specifically?
Trevor
03-11-2005, 09:56 PM
#5
this is the cheepest i found it just orded mine.. they have gold price i think
http://www.rx8garage.net/?page=shop/...cc4c6f9806117&
http://www.rx8garage.net/?page=shop/...cc4c6f9806117&
03-12-2005, 05:15 PM
#6
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There Is no Need for a Catch can when running low boost as with the Greddy kit, Catch can is mainly used under high amounts of boost 20-25 lbs, because the turbo creates so much force, oil acually spits out of the dipstick and the catch can reuses the oil that comes out. my boy is running 22lbs of boost on his FD and He doesnt have a catch can and hes fine, Save your Money....
03-13-2005, 05:29 PM
#8
Ex- member.
I'd recommend one.
Pictures below are from several stock RX8 owners that have found oil in their intake.
What is a catch can?
What is a breather filter?
A catch can is a small container, sometimes with a filter, that collects oil blown out of the PCV valve or valve cover intake hose. The idea is to keep the oil out of the intake, which helps keep the intercooler running at maximum efficiency. It has also been reported that the catch can mod can reduce the crankcase pressure, helping to eliminate the problem of having the oil dip stick pop out of the engine. It is necessary to periodically empty the catch can to prevent it from overflowing. Some cans provide a drain for this purpose.
Other people have installed a K&N 'breather' filter in place of the stock hose. The filter allows gases to escape but keeps liquid oil inside the block, thus providing the same benefit as the catch can without requiring maintenance. A few believe they are too restrictive, but many people have used them with good results. Unfortunately, the breather filter can sometimes allow oil to escape and get onto the engine.
Pictures below are from several stock RX8 owners that have found oil in their intake.
What is a catch can?
What is a breather filter?
A catch can is a small container, sometimes with a filter, that collects oil blown out of the PCV valve or valve cover intake hose. The idea is to keep the oil out of the intake, which helps keep the intercooler running at maximum efficiency. It has also been reported that the catch can mod can reduce the crankcase pressure, helping to eliminate the problem of having the oil dip stick pop out of the engine. It is necessary to periodically empty the catch can to prevent it from overflowing. Some cans provide a drain for this purpose.
Other people have installed a K&N 'breather' filter in place of the stock hose. The filter allows gases to escape but keeps liquid oil inside the block, thus providing the same benefit as the catch can without requiring maintenance. A few believe they are too restrictive, but many people have used them with good results. Unfortunately, the breather filter can sometimes allow oil to escape and get onto the engine.
03-17-2005, 08:04 PM
#13
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Catch can = cheap insurance against oil back flow in the air box. I run NA, AT, and got about 200 mL of oil in the stock air intake. As I install a drop-in K&N air filter, I'll also put a catch can. Just in case...
Last edited by bxb40; 05-07-2005 at 09:00 AM.
09-15-2005, 04:40 PM
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I too have been accumulating oil in the airbox and intake duct and so an oil catch is on my shopping list. But there are 3 vent hoses that appear to go into the air intake duct, so which one should vented through the catch tank? I had always assumed that the oil was getting into the intake from the vent on the oil filler pipe. I have read elsewhere on this site that the oil is most likely to be coming from the lowest of the 3 vents. Sounds logical. So, my question to those of you who have installed oil catrch tanks, which of the 3 vents did you connect to your catch tank?
Also my Mazda dealership is going to fit a new sump for me. This sump is of a new design and is supposed to reduce oil foaming problems while running at high engine revs. Does anyone have a view as to whether this new ant-foaming sump will help to reduce oil getting into my air inlet?
Also my Mazda dealership is going to fit a new sump for me. This sump is of a new design and is supposed to reduce oil foaming problems while running at high engine revs. Does anyone have a view as to whether this new ant-foaming sump will help to reduce oil getting into my air inlet?
09-15-2005, 05:12 PM
#15
wow...some of the explanations you guys are giving him.
simply, the oil catch can is a reservoir that catches oil mist produced by blow-by gases coming from the motor. the positive crankcase is where the blow-by gases exit and routed into the intake.
for a turbo charged car, since you are adding a lot more air, the positive pressure is going to be higher. which means you have more blow-by/oil shooting into your turbo (compressor side). too much oil shooting into the turbo can damage the fins and ultimately destroy the turbo (turbo bearing goes bad causing the turbo to leak oil internally) this would also mean more oil shooting into the combustion chamber.
basically, the oil catch can is a preventative to any damage to the turbo. i'd definately recommend you getting one. i'm surprised you haven't got one by now. since you have the GReddy kit already, go with the GReddy catch can. but make sure you get the square one...the oval shaped one doesn't look good IMO. the craftsman ship in the oval one looks half ***...the squared one is definately much better.
simply, the oil catch can is a reservoir that catches oil mist produced by blow-by gases coming from the motor. the positive crankcase is where the blow-by gases exit and routed into the intake.
for a turbo charged car, since you are adding a lot more air, the positive pressure is going to be higher. which means you have more blow-by/oil shooting into your turbo (compressor side). too much oil shooting into the turbo can damage the fins and ultimately destroy the turbo (turbo bearing goes bad causing the turbo to leak oil internally) this would also mean more oil shooting into the combustion chamber.
basically, the oil catch can is a preventative to any damage to the turbo. i'd definately recommend you getting one. i'm surprised you haven't got one by now. since you have the GReddy kit already, go with the GReddy catch can. but make sure you get the square one...the oval shaped one doesn't look good IMO. the craftsman ship in the oval one looks half ***...the squared one is definately much better.
09-15-2005, 05:14 PM
#16
Originally Posted by powerman
I too have been accumulating oil in the airbox and intake duct and so an oil catch is on my shopping list. But there are 3 vent hoses that appear to go into the air intake duct, so which one should vented through the catch tank? I had always assumed that the oil was getting into the intake from the vent on the oil filler pipe. I have read elsewhere on this site that the oil is most likely to be coming from the lowest of the 3 vents. Sounds logical. So, my question to those of you who have installed oil catrch tanks, which of the 3 vents did you connect to your catch tank?
Also my Mazda dealership is going to fit a new sump for me. This sump is of a new design and is supposed to reduce oil foaming problems while running at high engine revs. Does anyone have a view as to whether this new ant-foaming sump will help to reduce oil getting into my air inlet?
Also my Mazda dealership is going to fit a new sump for me. This sump is of a new design and is supposed to reduce oil foaming problems while running at high engine revs. Does anyone have a view as to whether this new ant-foaming sump will help to reduce oil getting into my air inlet?
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