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I'm just starting to look at the various catch cans on the market. I had a question about the check valves. The UPR catch can includes a check valve that goes in the line that feeds back into the intake manifold. I understand its purpose and get what it is there for, but I was wondering why some catch cans use one and others don't. Like I mentioned UPR is one that uses it. Radium however does not have a check valve in their catch can kit. Do any of you happen to know why some of the catch cans use one in the "out" line of the catch can and why some other catch cans don't have one in that line.
I think because Radium has the check valve in the baffle plate (theirs or the stock one) so same same.
 

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I found that the easiest way to get the CC out is to disassemble the mounting bracket from the engine mount, which is one bolt. I've been thinking about drilling and tapping a hole in the bottom of the CC to install a petcock and run a drain line down to the bottom but never have the time. Maybe this year...

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I was going to do the same after talking with UPR and like you I haven’t gotten around to it yet.
They have a remote drain kit they sell - you just need to tap the can for it.
 

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I think because Radium has the check valve in the baffle plate (theirs or the stock one) so same same.
No It doesn't. Like all breather plates for the RS engine it re uses the original PCV valve. The PCV valve does close under boost like a CV but I think the OP is referring to people that use a CV in addition to the PCV valve.
The only advantage as I said to adding the additional CV is to isolate the can from boost pressure when the induction pressure goes positive.

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Its just to isolate the catch can from boost pressure when the engine comes on boost as it will see boost pressure before the PCV valve at that time. Radium for instance say their can is quite capable of handling boost pressure and above so its not necessary.
This is prob a very noob question but aren't you loosing some amount of boost pressure without a CV? I'm asking because I decided to go for UPR over Radium just because of the CV and it would be a lot easier for me to get radium since I live in Europe.
 

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No It doesn't. Like all breather plates for the RS engine it re uses the original PCV valve. The PCV valve does close under boost like a CV but I think the OP is referring to people that use a CV in addition to the PCV valve.
The only advantage as I said to adding the additional CV is to isolate the can from boost pressure when the induction pressure goes positive.

Ciao
The radium pcv breather plate does use its own PCV valve instead of the stock one. I think that is one reason why their catch can hoses don't use a check valve. The other being like you mentioned, radium's cans themselves are designed to withhold the pressure, whereas, other cans such as UPR, they don't feel their cans can take the boost pressure so they include a check valve in the hose. Without the check valve, the PCV valve would still do its job preventing boost from going back into the crankcase, but if the cans can't hold the boost pressure, that would be a source of a boost leak right there. Obviously using the stock breather plate uses the stock PCV valve, but also upgrading to other aftermarket breather plates (such as mountune) they have you remove the stock PCV value (the blue one) from the stock plate and put it on their breather plate.

I think i've read somewhere online that you can buy radium's upgraded pcv vale that they use for their breather plate separately, and put that on the outlet side of the catch can itself, (if you are not using their breather plate and are sticking with stock or mountune's, etc.) and that would prevent their can from seeing boost pressure. Also there wouldn't be anything stopping you from buying the UPR check valve by itself and putting that in the outlet hose of a radium catch can either. But like they claim, they designed it to handle the pressure anyway, so a check valve is not needed. Boost would be built up all the way back through the hose and into the can itself, and then the PCV on the breather plate would do its job of preventing boost from going back into the crankcase.
338062
 

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The radium pcv breather plate does use its own PCV valve instead of the stock one. I think that is one reason why their catch can hoses don't use a check valve. The other being like you mentioned, radium's cans themselves are designed to withhold the pressure, whereas, other cans such as UPR, they don't feel their cans can take the boost pressure so they include a check valve in the hose. Without the check valve, the PCV valve would still do its job preventing boost from going back into the crankcase, but if the cans can't hold the boost pressure, that would be a source of a boost leak right there. Obviously using the stock breather plate uses the stock PCV valve, but also upgrading to other aftermarket breather plates (such as mountune) they have you remove the stock PCV value (the blue one) from the stock plate and put it on their breather plate.

I think i've read somewhere online that you can buy radium's upgraded pcv vale that they use for their breather plate separately, and put that on the outlet side of the catch can itself, (if you are not using their breather plate and are sticking with stock or mountune's, etc.) and that would prevent their can from seeing boost pressure. Also there wouldn't be anything stopping you from buying the UPR check valve by itself and putting that in the outlet hose of a radium catch can either. But like they claim, they designed it to handle the pressure anyway, so a check valve is not needed. Boost would be built up all the way back through the hose and into the can itself, and then the PCV on the breather plate would do its job of preventing boost from going back into the crankcase.
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Ok cool. I looked at plates and cans a few years ago and I'm sure at that time the radium plate still used the std PCV valve, maybe their valve is newer than the plate or maybe my memory is slipping. Either way if the catch can can handle the boost pressure then a check valve is just another restriction and complication (even simple check valves can fail and stick at times) in the vent system and adds additional possible leak points.Thirty psi is a very low pressure for a can like the radium to deal with.
As a side note I chose the mk2 version of the Mountune plate ( the one they dont sell in the US for some bazaar reason)and the dual radium cans.
 

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This is prob a very noob question but aren't you loosing some amount of boost pressure without a CV? I'm asking because I decided to go for UPR over Radium just because of the CV and it would be a lot easier for me to get radium since I live in Europe.
No because the PCV valve is in effect a reverse flow check valve for when the intake pressure goes positive.This is how the std factory setup works. The PCV valve has more functionally and is little more complicated than a std CV but one of its functions is it closes off when the manifold sees boost. So in reality the only difference is that with a can fitted when the inlet manifold sees boost pressure that pressure is transmitted to the PCV valve via a catch can to make it close as opposed to the exact same process just via a straight plain hose. As long as the can can withstand 30 psi or so then you dont have an issue and 30 psi for that quality of can (Radium) is nothing.

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No It doesn't. Like all breather plates for the RS engine it re uses the original PCV valve. The PCV valve does close under boost like a CV but I think the OP is referring to people that use a CV in addition to the PCV valve.
The only advantage as I said to adding the additional CV is to isolate the can from boost pressure when the induction pressure goes positive.

Ciao
Looks like @ItalianStallion beat me to it for the correction. As Radium offers more robust PCV as they say the OEM can leak under pressure.

I get what you are saying about the additional CV along with the PCV the OP was asking about and I remembered I asked UPR about that...

They talked to Radium and here is what I received back:

“They (Radium) confirmed it is an actual PCV valve and recommend using it if there is no check valve present in the kit, or if you are installing the plate without a catch can on the car. However, it can be used if there is an inline check valve present as both the PCV valve and check valves are essentially doing the same thing, at the same time depending on if the engine is under boost or vacuum. It would be as if you installed the catch can and left the stock PCV fitting in place, albeit the Radium fitting is probably night and day more efficient than the stock piece. “

Hope this helps clear up more.
 

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That is a very good question. If OCC's are so useful, work so well, and could be added by the manufacturer for about ten bucks; why aren't they OE?
The reasoning behind not including a catch can (at least what I've heard) is the manufacturers don't expect most owners to empty the cans as needed which would cause more problems.
 

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The reasoning behind not including a catch can (at least what I've heard) is the manufacturers don't expect most owners to empty the cans as needed which would cause more problems.
This is one of the very reasons - then overflow, engine damage, etc.
 

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The reasoning behind not including a catch can (at least what I've heard) is the manufacturers don't expect most owners to empty the cans as needed which would cause more problems.
Doubt that...they could just put it in their regular maintenance schedule and have dealers do it, same as with all other fluid checks, brakes, oil changes, etc. Pretty sure most owners aren't great with any maintenance. It seems like there must be another reason that no manufacturers do this...
 

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Doubt that...they could just put it in their regular maintenance schedule and have dealers do it, same as with all other fluid checks, brakes, oil changes, etc. Pretty sure most owners aren't great with any maintenance. It seems like there must be another reason that no manufacturers do this...
That's simply part of the reason. Add to that added cost (more partals, hardware, mounting brackets, tubing etc vs simply routing a tube into the intake), added complexity, which can lead to more points of failure/issue, and emissions regulations (in some areas, you'd be in violation if it starts leaking at the cab or at any of the additional joints/connections) that all can lead to warranty claims if not properly engineered (which also adds development costs) and now the argument for an OEM to put one in ain't so compelling.

Don't get me wrong, there are plenty of fleet vehicles, heavy duty trucks, farm equipment etc. that come with catch cans stock. They are also more expensive, get more maintenance and are considered "durable goods" that lasts years and years. A regular, mass produced passenger car that is meant to be obsolete within several years is probably just not worth it in the end.
 

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That's simply part of the reason. Add to that added cost (more partals, hardware, mounting brackets, tubing etc vs simply routing a tube into the intake), added complexity, which can lead to more points of failure/issue, and emissions regulations (in some areas, you'd be in violation if it starts leaking at the cab or at any of the additional joints/connections) that all can lead to warranty claims if not properly engineered (which also adds development costs) and now the argument for an OEM to put one in ain't so compelling.

Don't get me wrong, there are plenty of fleet vehicles, heavy duty trucks, farm equipment etc. that come with catch cans stock. They are also more expensive, get more maintenance and are considered "durable goods" that lasts years and years. A regular, mass produced passenger car that is meant to be obsolete within several years is probably just not worth it in the end.
This is true. It amazes me that people dont quite understand the corporate capitalistic model even today. So the RS engine is totally in 99% of cases going to go well beyond the warranty mileage before any valve coking issues cause problems. So as far as Ford corporate is concerned its not an issue that's a hitter for them. But think about the economics of it. If as someone proffered, a catch can set up costs $10/car to fit on the line and wasn't actually necessary from Fords perspective as a warranty claim issue that's $340,000 that goes straight to Fords bottom line and also makes production simpler.Every single part and process no matter how small comes under the most intense cost scrutiny. That's how we ended up with mustang head gaskets, except the engineering risk V benefit didn't pan out. But even then they went with the cheapest possible recovery programme they could muster.

Ciao
 

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And it's why we have the interior of a $10k car, lol cost
This is true. It amazes me that people dont quite understand the corporate capitalistic model even today. So the RS engine is totally in 99% of cases going to go well beyond the warranty mileage before any valve coking issues cause problems. So as far as Ford corporate is concerned its not an issue that's a hitter for them. But think about the economics of it. If as someone proffered, a catch can set up costs $10/car to fit on the line and wasn't actually necessary from Fords perspective as a warranty claim issue that's $340,000 that goes straight to Fords bottom line and also makes production simpler.Every single part and process no matter how small comes under the most intense cost scrutiny. That's how we ended up with mustang head gaskets, except the engineering risk V benefit didn't pan out. But even then they went with the cheapest possible recovery programme they could muster.

Ciao
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