Oil Cap Breather vs Separator
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Join Date: August 2, 2013
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Oil Cap Breather vs Separator
I will be installing a Steeda CAI and 93 octane tune once the car if finally out of storage. I was thinking about installing a catch can to aid with retaining the octane rating, but then I came across this.
https://lmr.com/item/UPR-501301/must...-5013-01-07-17
![](https://cfc7329ad537523a5de1-b21544d490ba797ec9de9d17e947de3d.ssl.cf1.rackcdn.com/upr-501301_69c5fc15.jpg)
It replaces the oil cap, and seems to have a similar function. It will clearly not "catch" any oil, other than what little makes it into the filter, but I guess it vents blow-by to atmosphere. Is it worth $69? Should I bother, or just get the catch can instead?
What are your thoughts?
https://lmr.com/item/UPR-501301/must...-5013-01-07-17
![](https://cfc7329ad537523a5de1-b21544d490ba797ec9de9d17e947de3d.ssl.cf1.rackcdn.com/upr-501301_69c5fc15.jpg)
It replaces the oil cap, and seems to have a similar function. It will clearly not "catch" any oil, other than what little makes it into the filter, but I guess it vents blow-by to atmosphere. Is it worth $69? Should I bother, or just get the catch can instead?
What are your thoughts?
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Under normal driving conditions and part throttle, the check ball valve remains closed just as a regular oil cap, but once your under boost and WOT, the check ball valve opens up and vents the crankcase..
IMHO they really do work very well and are designed to work with the factory PCV system in place with an oil separator/catch can..
I have the C-F-M billet version that's almost exactly identical to the UPR one your interested in.. IMO they are most definitely worth it and highly recommended to use with a catch can for added insurance..
Here's some images of my CFM setup below...
https://www.c-f-m.com/performancepar...-GT-847p86.htm
IMHO they really do work very well and are designed to work with the factory PCV system in place with an oil separator/catch can..
I have the C-F-M billet version that's almost exactly identical to the UPR one your interested in.. IMO they are most definitely worth it and highly recommended to use with a catch can for added insurance..
Here's some images of my CFM setup below...
https://www.c-f-m.com/performancepar...-GT-847p86.htm
Last edited by m05fastbackGT; 2/6/17 at 09:20 PM.
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I will be installing a Steeda CAI and 93 octane tune once the car if finally out of storage. I was thinking about installing a catch can to aid with retaining the octane rating, but then I came across this.
https://lmr.com/item/UPR-501301/must...-5013-01-07-17
![](https://cfc7329ad537523a5de1-b21544d490ba797ec9de9d17e947de3d.ssl.cf1.rackcdn.com/upr-501301_69c5fc15.jpg)
It replaces the oil cap, and seems to have a similar function. It will clearly not "catch" any oil, other than what little makes it into the filter, but I guess it vents blow-by to atmosphere. Is it worth $69? Should I bother, or just get the catch can instead?
What are your thoughts?
https://lmr.com/item/UPR-501301/must...-5013-01-07-17
![](https://cfc7329ad537523a5de1-b21544d490ba797ec9de9d17e947de3d.ssl.cf1.rackcdn.com/upr-501301_69c5fc15.jpg)
It replaces the oil cap, and seems to have a similar function. It will clearly not "catch" any oil, other than what little makes it into the filter, but I guess it vents blow-by to atmosphere. Is it worth $69? Should I bother, or just get the catch can instead?
What are your thoughts?
According to some users................your engine compartment !!
.
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Thread Starter
Join Date: August 2, 2013
Location: Little north of Stuttgart, Germany
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Under normal driving conditions and part throttle, the check ball valve remains closed just as a regular oil cap, but once your under boost and WOT, the check ball valve opens up and vents the crankcase..
IMHO they really do work very well and are designed to work with the factory PCV system in place with an oil separator/catch can..
I have the C-F-M billet version that's almost exactly identical to the UPR one your interested in.. IMO they are most definitely worth it and highly recommended to use with a catch can for added insurance..
Here's some images of my CFM setup below...
https://www.c-f-m.com/performancepar...-GT-847p86.htm
IMHO they really do work very well and are designed to work with the factory PCV system in place with an oil separator/catch can..
I have the C-F-M billet version that's almost exactly identical to the UPR one your interested in.. IMO they are most definitely worth it and highly recommended to use with a catch can for added insurance..
Here's some images of my CFM setup below...
https://www.c-f-m.com/performancepar...-GT-847p86.htm
I was hoping I could get away with using this in place of a catch can to be honest. I don't really like the idea of a catch can, but now that I'm about to start running premium only in my motor I'm considering it.
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Nice! Thanks for the feedback. How oily does the filter get? Do you ever find oil drips from the vent?
I was hoping I could get away with using this in place of a catch can to be honest. I don't really like the idea of a catch can, but now that I'm about to start running premium only in my motor I'm considering it.
I was hoping I could get away with using this in place of a catch can to be honest. I don't really like the idea of a catch can, but now that I'm about to start running premium only in my motor I'm considering it.
Case vents are really designed for race engines that get serviced and fresh oil after every race weekend and are not ideal for street driven cars. Because they don’t remove the blow-by gasses and condensate from the crankcase, those contaminants build up inside of it.The end result is your oil will contaminate with acids and moisture causing them to prematurely break down and cause sludging inside the engine. One last thing, quite often users notice a slow deposition oil film on under-hood surfaces and more importantly the windshield.
In our circletrack cars we always used a scavenge tube connected to the headers. It acted like a venturi and very effectively drew air through the valve cover vents and tossed it into the exhaust. Other side benefits to a neutral or low pressure in the crankcase are reduced parasitic drag (The pistons are not compressing blow-by gasses on their way down)...this also aids the ring seal.
Your car,y our decision but unless used wisely and correctly, they’re not for me!
John
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I am not sure why you're reluctant to run a catch can, but I know from experience that they do remove oil from the vapor being drawn into the engine through the breather system. How much or how well can vary depending on the can's design. IMO you will be hard pressed to find one that equals much less exceeds Bob's for quality of design, construction, media efficiency and ease of service. I wanted to be able to return my car back to stock so I bought a passenger side pipe and fittings from my local Ford dealer so I could use the fittings from it and save my original one in case I ever remove the catch can. The plastic pipe and fittings cost under $20.00 and it was easy to remove the fittings from the factory piece after softening it with a heat gun. Since Bob's has a ball valve at the bottom there isn't any need to disassemble anything to drain the can. FWIW I also found the service from Bob's to be excellent. I have a track key for my '14 GT, but most of the time I just use the standard key and regular fuel. Naturally when I do use the track key I make sure to have only 91 or 93 octane fuel in the tank. In any case pinging or detonation has never been an issue.
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Nice! Thanks for the feedback. How oily does the filter get? Do you ever find oil drips from the vent?
I was hoping I could get away with using this in place of a catch can to be honest. I don't really like the idea of a catch can, but now that I'm about to start running premium only in my motor I'm considering it.
I was hoping I could get away with using this in place of a catch can to be honest. I don't really like the idea of a catch can, but now that I'm about to start running premium only in my motor I'm considering it.
In other words, the check ball valve only opens up when PCV vacuum routed to the intake manifold closes under boost and WOT in order to vent the crankcase, otherwise as I mentioned, the check ball valve remains closed and functions just like an ordinary oil cap.. Btw: also no oil drips from anywhere..
That being said, the purpose of these oil cap/check valve breathers are designed to function in conjunction alongside an oil separator/catch can with the factory PCV system fully intact..
Last edited by m05fastbackGT; 2/7/17 at 04:58 PM.
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I am not sure why you're reluctant to run a catch can, but I know from experience that they do remove oil from the vapor being drawn into the engine through the breather system. How much or how well can vary depending on the can's design. IMO you will be hard pressed to find one that equals much less exceeds Bob's for quality of design, construction, media efficiency and ease of service. I wanted to be able to return my car back to stock so I bought a passenger side pipe and fittings from my local Ford dealer so I could use the fittings from it and save my original one in case I ever remove the catch can. The plastic pipe and fittings cost under $20.00 and it was easy to remove the fittings from the factory piece after softening it with a heat gun. Since Bob's has a ball valve at the bottom there isn't any need to disassemble anything to drain the can. FWIW I also found the service from Bob's to be excellent. I have a track key for my '14 GT, but most of the time I just use the standard key and regular fuel. Naturally when I do use the track key I make sure to have only 91 or 93 octane fuel in the tank. In any case pinging or detonation has never been an issue.
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Case vents are really designed for race engines that get serviced and fresh oil after every race weekend and are not ideal for street driven cars. Because they don’t remove the blow-by gasses and condensate from the crankcase, those contaminants build up inside of it.The end result is your oil will contaminate with acids and moisture causing them to prematurely break down and cause sludging inside the engine. One last thing, quite often users notice a slow deposition oil film on under-hood surfaces and more importantly the windshield.
In our circletrack cars we always used a scavenge tube connected to the headers. It acted like a venturi and very effectively drew air through the valve cover vents and tossed it into the exhaust. Other side benefits to a neutral or low pressure in the crankcase are reduced parasitic drag (The pistons are not compressing blow-by gasses on their way down)...this also aids the ring seal.
Your car,y our decision but unless used wisely and correctly, they’re not for me!
John
I know this through personal experience and haven't ran into any negative issues at all during the past year since I began using it alongside my oil separator/catch cans..
-Rocky
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I installed the Moroso Oil Separator a couple years back. Works great. It is a fairly large one. It has a relief valve so it is easy to empty, dont have to disassemble to empty. I usually drain it about every 1000 miles. Seems to catch quite a bit of oil, I'd say somewhere between 1 to 2 ounces. I am very happy with this unit. I also bought a second pvc hose assembly from my Ford dealer to butcher and pull the ends off for installation. Wanted to keep my original hose in case I decided to go back to stock. Personally I prefer a separator over a breather.
Last edited by shaneyusa; 2/7/17 at 09:32 PM.
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I have ran a moroso catch can since less than 100 miles,
I have been very happy, my throttle body and intake are like new
Not even a little oil residue!
I have been very happy, my throttle body and intake are like new
Not even a little oil residue!
Last edited by ElkGroveFordGuy; 2/7/17 at 10:12 PM.
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John ! I really hate to disagree, however the c-f-m oil cap breather is not an open breather element, but is actually a one way check valve that includes a breather filter which only opens one way to allow crankcase vapors to escape during pressurization, it does not allow anything back into the crankcase whatsoever.. It also functions just like an ordinary oil cap under part throttle and normal driving conditions in which the check valve remains fully closed..
I know this through personal experience and haven't ran into any negative issues at all during the past year since I began using it alongside my oil separator/catch cans..
-Rocky
I know this through personal experience and haven't ran into any negative issues at all during the past year since I began using it alongside my oil separator/catch cans..
-Rocky
I stand by what I wrote previously…and now that the function of that particular breather has been explained I understand. It wasn’t clear to me prior. It’s actually a crankcase pressure pop-off valve of sorts for supercharged engines. When the blow-by under power overwhelms the PCV system, it opens and vents the balance rather than pushing the blow-by gasses into the air cleaner housing. Call me dense but I still don’t see the need in an non-supercharged application…unless you have really bad rings!
John
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I stand by what I wrote previously…and now that the function of that particular breather has been explained I understand. It wasn’t clear to me prior. It’s actually a crankcase pressure pop-off valve of sorts for supercharged engines. When the blow-by under power overwhelms the PCV system, it opens and vents the balance rather than pushing the blow-by gasses into the air cleaner housing. Call me dense but I still don’t see the need in an non-supercharged application…unless you have really bad rings!
John
So yes, it's function is to open and vent the crankcase when the factory PCV system becomes inactive while under WOT and boosted conditions and therefore as you said, prevents blow-by gases from being pushed into the combustion chamber through the air cleaner housing..
I'll also add by saying these oil cap/check valve breathers were not designed to replace an oil separator/catch can, but are actually designed to function with them..
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All those oil vapors and oil residue cause the octain level of your fuel to drop and cause earlier detonation which robs H.P. Even on a completely stock car with no tune you will make max HP by not having the computer adjust for engin detonation caused by the oil residue and vapor!
Thus you want a oil separator!
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It actually took going through 3 different oil separators before finally finding the right one's that not only catch crankcase blow-by, but also stop it from entering the crankcase through the intake manifold to begin with..
The first was JLT.. Although it did capture a small amount of crankcase blow-by, there was still quite a bit that got through it's small filtering screen and into the combustion chamber through the intake manifold..
My best results have been with the Bob's autosports oil separator which has a similar chamber and filtering design with Moroso.. I've also had great results with UPR's 4 chamber design catch can as well in which no crankcase blow-by has got past the PCV hose connectors at the intake manifold whatsoever
The first was JLT.. Although it did capture a small amount of crankcase blow-by, there was still quite a bit that got through it's small filtering screen and into the combustion chamber through the intake manifold..
My best results have been with the Bob's autosports oil separator which has a similar chamber and filtering design with Moroso.. I've also had great results with UPR's 4 chamber design catch can as well in which no crankcase blow-by has got past the PCV hose connectors at the intake manifold whatsoever
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If you don't think you need a catch can or breather system on a N/A motor, just go pull the throttle body off any mustang without a seperator and you will see all the oil residue built up in the throtle body and inside the intake manifold!
All those oil vapors and oil residue cause the octain level of your fuel to drop and cause earlier detonation which robs H.P. Even on a completely stock car with no tune you will make max HP by not having the computer adjust for engin detonation caused by the oil residue and vapor!
Thus you want a oil separator!![Thumb](https://themustangsource.com/forums/images/smilies/thumb.gif)
All those oil vapors and oil residue cause the octain level of your fuel to drop and cause earlier detonation which robs H.P. Even on a completely stock car with no tune you will make max HP by not having the computer adjust for engin detonation caused by the oil residue and vapor!
Thus you want a oil separator!
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