[98Cobra_sleeper]

i was researching this. I believe i should have one, or two. Where would i hook it up without issues being that im boosted? i was thinking i should use UPR's can because its not vented to atmosphere. i dont want oil sprayed on my engine bay.

[WickedSnake00]

One is fine.

The plumbing is rather simple as well. You just run the two PCV lines on your valve covers to the catch can.

If it's a good vented catch can it should have a filter to keep all the oil mist off your engine. If you don't want to take the change, use one of the non-vented ones, and route the return/outlet back to the intake elbow.

[98Cobra_sleeper]

only issue ive read is how can u prevent pressurizing the crankcase?

[musclemerc]

I would advise to not run both sides of the pcv into the catch can

The catch can should run between the pcv valve and the intake.

You may be a little dissapointed in the UPR catch cans ability to stop oil vapors. The single plate design is not capable of stopping blow by or vapors

[WickedSnake00]

Originally Posted by 98Cobra_sleeper only issue ive read is how can u prevent pressurizing the crankcase?

If you've got anything running from the PCV ports you're allowing the excess pressure to be relieved.

To drop it further you need to apply vacuum, which means plumb it to the low pressure side of the intake.

Originally Posted by musclemerc I would advise to not run both sides of the pcv into the catch can The catch can should run between the pcv valve and the intake. You may be a little dissapointed in the UPR catch cans ability to stop oil vapors. The single plate design is not capable of stopping blow by or vapors

Well if the catch can is in between the PCV and intake it's not much of a catch can, it's a coalescing oil filter. But you're right, a coalescing oil filter is more desirable than a catch can.

It may just be semantics. A "catch can" is a can that basically allows the oil to be dumped in from the PCV, but with a filter at the top to allow gases to escape to atmosphere.

A coalescing oil filter (oil separator) takes the PCV gases, seperates the oil out of the gas, and allows the gas to go back into the intake. It's the same as the stock PCV system, but with the oil separator stuck in between the valve covers and intake.

[musclemerc]

Originally Posted by WickedSnake00 One is fine. The plumbing is rather simple as well. You just run the two PCV lines on your valve covers to the catch can.If it's a good vented catch can it should have a filter to keep all the oil mist off your engine. If you don't want to take the change, use one of the non-vented ones, and route the return/outlet back to the intake elbow.

Originally Posted by WickedSnake00 If you've got anything running from the PCV ports you're allowing the excess pressure to be relieved. To drop it further you need to apply vacuum, which means plumb it to the low pressure side of the intake. Well if the catch can is in between the PCV and intake it's not much of a catch can, it's a coalescing oil filter. But you're right, a coalescing oil filter is more desirable than a catch can. It may just be semantics. A "catch can" is a can that basically allows the oil to be dumped in from the PCV, but with a filter at the top to allow gases to escape to atmosphere. A coalescing oil filter (oil separator) takes the PCV gases, seperates the oil out of the gas, and allows the gas to go back into the intake. It's the same as the stock PCV system, but with the oil separator stuck in between the valve covers and intake.

For the pcv system to work correctly it has to have an inlet/outlet. On a 4v the inlet is metered (air comming in after the MAF) the outlet feeds back to the upper intake so (in theory) the oil, water vapors, and oil vapors can be burned in the combustion chamber. If you tie both cam covers together then where is the inlet? They would both become outlets and the vent on the top of the can will relieve the crankcase pressure (along with engine oil, water vapors, and the oily smell) directly to the atmosphere.

I wouldnt run a catch can with a vent but thats just me. Closed loop is the only way to go. The biggest issue with most catch can Mfgs. is they start with the wrong design. None of them do anything to stop oil vapors and all of them have the inlet/outlet in the same location (at the top of the can) where the supposedly clean air going out is just as contaminated as the dirty air comming in.

Here is a thread I wrote on catch cans:
Catch Can Comparisons

[WickedSnake00]

Originally Posted by musclemerc For the pcv system to work correctly it has to have an inlet/outlet. On a 4v the inlet is metered (air comming in after the MAF) the outlet feeds back to the upper intake so (in theory) the oil, water vapors, and oil vapors can be burned in the combustion chamber. If you tie both cam covers together then where is the inlet? They would both become outlets and the vent on the top of the can will relieve the crankcase pressure (along with engine oil, water vapors, and the oily smell) directly to the atmosphere. I wouldnt run a catch can with a vent but thats just me. Closed loop is the only way to go. The biggest issue with most catch can Mfgs. is they start with the wrong design. None of them do anything to stop oil vapors and all of them have the inlet/outlet in the same location (at the top of the can) where the supposedly clean air going out is just as contaminated as the dirty air comming in. Here is a thread I wrote on catch cans: Catch Can Comparisons

It's really a comparison of CCV vs OCV (I also did a writeup on this, waiting to get it published in the tech section.)

Since he's got a catch can, which I'm assuming is vented, it's OCV. I also assumed he would plug the return port in the intake elbow to prevent unmetered air. This is an old school technique, and is about the same as the old big blocks with breathers on the valve covers, but cleaner. The upside of this routing is you keep oil consumption and contamination down by sucking less oil into the intake (ideally none).

CCV is the optimial situation, but only with a separator. That's basically the stock lines, but with an element to remove the oil from the blowby. This drops crankcase pressure for more power using intake vacuum and removes the oil before it gets in the intake.


As far as your comment of the PCV system needing an "inlet" I don't believe that is necessarily true. The blowby is effectively the inlet. Excess pressure that makes it past the rings is where the air gets in, and you have to vent that out.

[musclemerc]

The UPR catch can the OP mentioned he has is the same unit I included on my comparison.

It does not have a vent.... He will be running a closed loop system....

[WickedSnake00]

Originally Posted by musclemerc The UPR catch can the OP mentioned he has is the same unit I included on my comparison. It does not have a vent.... He will be running a closed loop system....

I must have had the wrong model in mind. When I hear "catch can" I think well, a vented catch can. Otherwise I think of a coalescing filter.


Going back to the original question, if the UPR is a seperator, plumb it in between your valve covers and your intake and you're done. Then don't forget to drain it now and then.

[musclemerc]

What your referring to as a coalesing filter is not an oil seperator, but it is an "air" separator commonly used on an air compressor to remove water dropplets from compressed air.

An "air" separator will do nothing to stop oil vapors or wet oil? The filter element is'nt designed to "separate" anything as heavy as oil. They barely work well enough separating water dropplets.

Do some research on what synthetic oil does to the filter element on an "air " separator.

[WickedSnake00]

Originally Posted by musclemerc What your referring to as a coalesing filter is not an oil seperator, but it is an "air" separator commonly used on an air compressor to remove water dropplets from compressed air. An "air" separator will do nothing to stop oil vapors or wet oil? The filter element is'nt designed to "separate" anything as heavy as oil. They barely work well enough separating water dropplets. Do some research on what synthetic oil does to the filter element on an "air " separator.

Maybe we're having a problem with words again. We do refer to application specific designs on engines as both "separators" and "coalescing filters." "Breather" is also an acceptable term here, though to some this would mean an open filter on the valve cover.

Take a look at this:


See that big ass black box that sits on top of the valve cover? Call it what you want, separator (after all, it does separate oil from blowby gas), coalescing filter, or breather. It's a big ass box where blowby gases go in, oil is filtered out and returned to the crankcase, and the filtered air is sent on its merry way (you can see the tube that goes into the turbo inlet). That is what I mean when I say any of the above terms.

Ya dig?

[HBK_2007]

awwww... what a cute little isb

[98Cobra_sleeper]

well i havent bought a catch can yet. my turbos are mounted behind the headlights, so running lines to the intake might not be feasible. if i run a line from after the intercooler (intake pipe that leads to TB) from the 'OUT' line of the catchcan/ oil separator then it'll recieve boost.