Oil catch cans and or breathers
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Joined: Jan 2007
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From: Sin City
Oil catch cans and or breathers
I know this is talked about a lot over in the FI section and some with the street kids but ....... Let's talk high rpm track use.
I know we have two separate sides we can set up. Coming off the PVC and coming off the drivers side valve cover to inlet pipe.
My motor is getting old and I'm pulling a ton of oil from both. I want to extend its life a bit till I figure out the direction of the car.
So two separate closed tanks , one vented to atmosphere tank running to both valve covers, a combo. Let's have a nice discussion.
I know we have two separate sides we can set up. Coming off the PVC and coming off the drivers side valve cover to inlet pipe.
My motor is getting old and I'm pulling a ton of oil from both. I want to extend its life a bit till I figure out the direction of the car.
So two separate closed tanks , one vented to atmosphere tank running to both valve covers, a combo. Let's have a nice discussion.
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Joined: Aug 2002
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From: NC
I know this is talked about a lot over in the FI section and some with the street kids but ....... Let's talk high rpm track use.
I know we have two separate sides we can set up. Coming off the PVC and coming off the drivers side valve cover to inlet pipe.
My motor is getting old and I'm pulling a ton of oil from both. I want to extend its life a bit till I figure out the direction of the car.
So two separate closed tanks , one vented to atmosphere tank running to both valve covers, a combo. Let's have a nice discussion.
I know we have two separate sides we can set up. Coming off the PVC and coming off the drivers side valve cover to inlet pipe.
My motor is getting old and I'm pulling a ton of oil from both. I want to extend its life a bit till I figure out the direction of the car.
So two separate closed tanks , one vented to atmosphere tank running to both valve covers, a combo. Let's have a nice discussion.
I'm also on a single can, but then again I'm only venting a single head on the LS motor. I actually found that the interior of the can had the greatest effect on its functionality.
Thread Starter
Joined: Jan 2007
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From: Sin City
So I'm looking at this here http://www.jegs.com/i/JEGS-Performan...oductId=760016 then run one to the Pvc ( drilled out, or changed to a fitting ) then the other port to the back of the drivers valve cover. The block off the port to the manifold and inlet pipe.
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Joined: Apr 2015
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From: NY Long Island
So I'm looking at this here http://www.jegs.com/i/JEGS-Performan...oductId=760016 then run one to the Pvc ( drilled out, or changed to a fitting ) then the other port to the back of the drivers valve cover. The block off the port to the manifold and inlet pipe.
Last edited by wisniaPl; Sep 17, 2015 at 08:39 AM.
There is no internal baffling in that can. Your relying on just the can wall to separate the air and oil which will only work marginally at best.
Also correct me if I'm wrong, but won't that allow unmetered air to enter the engine since its behind the MAF?
Also correct me if I'm wrong, but won't that allow unmetered air to enter the engine since its behind the MAF?
Last edited by armt350z; Sep 17, 2015 at 09:01 AM.
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From: NY Long Island
u can always put chceck valve so air is only getting out not pulling in.... Btw a hose going from one othe valve covers goes to intake port behind maf in a stock form any way.......and you are right he needs cc with internal baffle...
Ill throw this here
http://www.evolutionm.net/forums/evo...nlet-tube.html
I did the same baffling to my cheap ebay cc...but added 10an ports and ss braided hoses and breather for clean install.Yo
Last edited by wisniaPl; Sep 17, 2015 at 09:31 AM.
You couldn't use it as a vacuum source because its receiving an unknown amount of air from the crank case blow bye. But the intake tube on an N/A car is always under some sort of vacuum. If you add a breather, all you are doing is adding a source of air to get sucked through to the intake. Since that source is behind the MAF its going to be unmetered.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
Thread Starter
Joined: Jan 2007
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From: Sin City
Wouldn't think a baffle is needed if it's vented to atmosphere. If I was doing it like the non modded diagram, I believe a baffled system would be better
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Joined: Apr 2015
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From: NY Long Island
You couldn't use it as a vacuum source because its receiving an unknown amount of air from the crank case blow bye. But the intake tube on an N/A car is always under some sort of vacuum. If you add a breather, all you are doing is adding a source of air to get sucked through to the intake. Since that source is behind the MAF its going to be unmetered.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
That should make engine bay less saturated with smell.....just like they do on motorcycles
Last edited by wisniaPl; Sep 17, 2015 at 12:10 PM.
Ah gotcha, I was under the assumption the motors in question were N/A. Just throw a one way check valve in between the CC and the intake tube and your diagram works. Thats how My RB26 is routed.
So I'm looking at this here http://www.jegs.com/i/JEGS-Performan...oductId=760016 then run one to the Pvc ( drilled out, or changed to a fitting ) then the other port to the back of the drivers valve cover. The block off the port to the manifold and inlet pipe.
This is my current setup, but I run the kit sold by a local tuner shop.
http://projectimport.com/store/pi-35...catch-can-kit/
a bit expensive though, but I had alot of oil in my intake beforehand, even reaching my spark plugs.
Glad you made your purchase, take pics. I would run it the same as you are, vented one can. If it were my daily, I would run a closed system two baffled cans.
Vented to atm:
-Need to block port on manifold and port on intake tube, drill/replace PCV valve
-No baffles needed
-One can or two no difference (so just do one)
-Completely eliminates any oil and dirty air recirculation
-All you are doing is relieving excess pressure in the crankcase
Closed system:
-Retain stock circuit, retain PCV valve
-Baffled can(s) necessary
-Two can design is necessary to retain oem pcv function, both sides flow differently at different load states
-The amount of oil caught depends on can design and your specific motor, but at the very least you are still introducing "dirty" air back into the intake by maintaining a recirculating PCV system
-Pundits say introducing a vacuum sucks out corrosive gasses, vapor and moisture
Obviously less pollution is the main benefit of a PCV system. As to vacuuming the corrosive gasses/oil vapor/moisture point, I really dont know. I would assume if youre running the car and changing your oil regularly that point is probably somewhat moot.
Vented to atm:
-Need to block port on manifold and port on intake tube, drill/replace PCV valve
-No baffles needed
-One can or two no difference (so just do one)
-Completely eliminates any oil and dirty air recirculation
-All you are doing is relieving excess pressure in the crankcase
Closed system:
-Retain stock circuit, retain PCV valve
-Baffled can(s) necessary
-Two can design is necessary to retain oem pcv function, both sides flow differently at different load states
-The amount of oil caught depends on can design and your specific motor, but at the very least you are still introducing "dirty" air back into the intake by maintaining a recirculating PCV system
-Pundits say introducing a vacuum sucks out corrosive gasses, vapor and moisture
Obviously less pollution is the main benefit of a PCV system. As to vacuuming the corrosive gasses/oil vapor/moisture point, I really dont know. I would assume if youre running the car and changing your oil regularly that point is probably somewhat moot.
I have a Mishimoto catch can that doesn't have a breather, but I don't want to drill a hole into it. Wouldn't it be the same thing if u added a T fitting between both valve cover hoses into one port on the catch can and just added a filter to the other port to relieve the pressure?
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Joined: Jan 2015
Posts: 166
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From: So.Cal.
You couldn't use it as a vacuum source because its receiving an unknown amount of air from the crank case blow bye. But the intake tube on an N/A car is always under some sort of vacuum. If you add a breather, all you are doing is adding a source of air to get sucked through to the intake. Since that source is behind the MAF its going to be unmetered.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
To make the PCV system functional it needs to have some sort of vacuum to assist and pull out the oil vapor which is why its connected to the intake tube. In old 50's era cars the crankcases were hooked up to a slotted tube that ran under the can and the air flowing by the tube opening during driving provided the vacuum source.
Just venting to atmosphere is also no bueno since it would only make the engine bay smell horribly like burnt oil but also has insufficient vacuum to properly vent the crank case.
This is all in reference to N/A cars FYI.
If you have a vent on your can in an N/A car now your STFT and LTFT's have got to be way off spec.
TLDR : Don't vent the catch can.
I shut the plenum port and the other port on the intake tube. Then connected the hollowed out PCV to one side of the can and the other side to the driver side valve cover. There seems to be a thin mist coming out of the breather but no oil has been trapped in the can so far.
Should I just cap off the breather? Would it still be possible to run it the same way? I prefer to keep the plenum port not connected to the valve cover.