PCV Oil Catch Can, see what your engine is burning!

[BlazerLT]

Originally Posted by Brian R.

As I said, if you leave the filter in, you better have a way of check it's contribution to flow restriction as time goes on. Your short time using it is not indicative of how it will perform in your truck (nor in other's trucks) in the future. How much it resticts the flow now and how much it restricts the flow in 20k miles are two different things.

Regardless of what happens in your truck, i think it is advisable for everyone who tampers with the PCV system to be cautious and be aware of how much each truck differs in blow-by, as well as oil viscosity.

Extrapolating advise to everyone on the basis of what is best for your truck is chancy in this type of modification, at best.

All I am communicating is what I have noticed and what performs the best through my in-hand testing.

If you are concerned about restrictions, you can always clean it every 10,000 miles or clean it everytime you dump out the trapped oil.

Reagardless, the benefits out-weigh all drawbacks and if anyone is concerned you, can see the 1000s of them on ebay and on racing and performance enthusiest sites along with the links in the top starting post in this thread.

Thanks for your contribution Brian, I rally appreciate it.

[BlazerLT]

Originally Posted by drdd

with the filter and catch can being oriented at 90 degrees to the hose/air flow ... ... ... how is the oil/air/fuel/gunk being drawn towards the filter and into the can?

does the filter extend up into the black plastic part with the directional arrow? meaning all flow must go thru the filter first?

The outlet for the separator is actually the filter in the center. The inlet spins the air around the ouside causing the vortex you see in the video earlier. The cleaner air is sucked up through the center and then into the intake.

[Brian R.]

Originally Posted by BlazerLT

All I am communicating is what I have noticed and what performs the best through my in-hand testing.

If you are concerned about restrictions, you can always clean it every 10,000 miles or clean it everytime you dump out the trapped oil.

Reagardless, the benefits out-weigh all drawbacks and if anyone is concerned you, can see the 1000s of them on ebay and on racing and performance enthusiest sites along with the links in the top starting post in this thread.

I understand your purpose exactly and I am not misinterpreting that at all. I am just making sure that everyone sees the possible problems with this system. I don't care if everyone in the world uses it. Popularity has very little to do with functionality, particularly when there is a drawback that is not easily measured, as there is in this case. I am not concerned about restrictions (since I will not install this) but everyone who does install it better be concerned about restrictions. I am only concerned about their engines.

Your caution about washing the filter periodically is exactly the type of caution that needed to be submitted up front, and my point in bringing this to everyone's attention since it was obviously overlooked. I think it is absolutely necessary to either check it by flow, or clean it. How often is going to be each person's responsibility to determine for their engine and driving habits, oil viscosity, etc. If their engine gunks up the PCV valve, it will certainly gunk up that filter over time.

[ZL1power69]

so either don't use the filter or use it, but clean it when u dump out the contamenents. thats all u had to say.

[drdd]

sorry to be so 'un-scientific' but ... if it flows (with no change in vacuum or rpms or idel), then, it flows! right!

of course, oil will slightly restrict flow ...

all filters (and the junk that they collect) slightly restrict flow ... thats why we replace filters ...


" ... It's up to you whether you want to keep the filter or not, but you'd better keep an eye on it and have some way of telling if it is restricting PCV system flow.[/QUOTE ... "

IS NOT THE CATCH-CAN ITSELF A WAY OF TELLING IF IT IS RESTRICTING PCV SYSTEM FLOW ???!!!

If idle/vacuum are OK, and oil/gas/vapors are collecting in the can ... what other evidence is necessary ???

Originally Posted by Brian R.

The oil that is in the filter will restrict flow through the filter. It will continuously and slowly flow through the filter, slowly since the oil is viscous, and continuously since once it flows through the filter, it will be replaced by more oil from the crankcase. Your oil viscosity and dilution will change how much the filter restricts flow, so each engine will have different restrictions. As the filter gets dirty, it will restrict more.

The PCV valve is the biggest restriction in the stock system by alot. If you hook up bigger tubing, it will not make any difference to the flow since it will not affect the PCV valve restriction. Also, the PCV valve is either on or off. There is no variability to how open it is. If it clicks closed, it is closed. If it clicks open, it is open. If the filter becomes nearly as restrictive or more restrictive than the PCV valve, then the total restriction of the PCV system will increase and you will get less flow out of the crankcase.

It's up to you whether you want to keep the filter or not, but you'd better keep an eye on it and have some way of telling if it is restricting PCV system flow.

[BlazerLT]

Originally Posted by Brian R.

I understand your purpose exactly and I am not misinterpreting that at all. I am just making sure that everyone sees the possible problems with this system. I don't care if everyone in the world uses it. Popularity has very little to do with functionality, particularly when there is a drawback that is not easily measured, as there is in this case. I am not concerned about restrictions (since I will not install this) but everyone who does install it better be concerned about restrictions. I am only concerned about their engines.

Your caution about washing the filter periodically is exactly the type of caution that needed to be submitted up front, and my point in bringing this to everyone's attention since it was obviously overlooked. I think it is absolutely necessary to either check it by flow, or clean it. How often is going to be each person's responsibility to determine for their engine and driving habits, oil viscosity, etc. If their engine gunks up the PCV valve, it will certainly gunk up that filter over time.

If you have a bad restriction in this PCV system on this truck, you wil know it. The engine wil actually start to stumble and the idle rpms will fall low enough that the engine idle rather poorly.

If you want a test for that when you install this system, pinch the PCV hose between your thumb and index finger and you will hear the engine idle drop about 100rpms. You release and the idle sooths out perfectly.

[BlazerLT]

Originally Posted by drdd

sorry to be so 'un-scientific' but ... if it flows (with no change in vacuum or rpms or idel), then, it flows! right!

of course, oil will slightly restrict flow ...

all filters (and the junk that they collect) slightly restrict flow ... thats why we replace filters ...


" ... It's up to you whether you want to keep the filter or not, but you'd better keep an eye on it and have some way of telling if it is restricting PCV system flow.[/QUOTE ... "

IS NOT THE CATCH-CAN ITSELF A WAY OF TELLING IF IT IS RESTRICTING PCV SYSTEM FLOW ???!!!

If idle/vacuum are OK, and oil/gas/vapors are collecting in the can ... what other evidence is necessary ???

This is true, there is plenty of flow through it seeing if you pinch the new tubng the engine actually starts to stumble and the idle drops, you release and the idle comes back up to normal.

[Brian R.]

Originally Posted by ZL1power69

so either don't use the filter or use it, but clean it when u dump out the contamenents. thats all u had to say.

No. Apparently, in BlazerLT's engine, you have to use the filter to add restriction. If your engine is exactly the same as his, then you better use the filter too.

[Brian R.]

Originally Posted by drdd

sorry to be so 'un-scientific' but ... if it flows (with no change in vacuum or rpms or idel), then, it flows! right!

of course, oil will slightly restrict flow ...

all filters (and the junk that they collect) slightly restrict flow ... thats why we replace filters ...


" ... It's up to you whether you want to keep the filter or not, but you'd better keep an eye on it and have some way of telling if it is restricting PCV system flow.[/QUOTE ... "

IS NOT THE CATCH-CAN ITSELF A WAY OF TELLING IF IT IS RESTRICTING PCV SYSTEM FLOW ???!!!

If idle/vacuum are OK, and oil/gas/vapors are collecting in the can ... what other evidence is necessary ???

Yes, it will always flow to some extent. How much restriction you can tolerate without additional oil contamination is unknown.

Yes, that is why you replace filters. I don't believe that most people who read the first few posts in this thread would replace or clean that filter periodically. It's my job to make sure that any advice given out is as complete as possible so that anyone who reads about any recommendations on this site isn't mislead or remains even partially uninformed. I have to be more careful than the average poster. The reputation of this site and this forum is at stake.

No, the catch-can will not tell you what flow is going through the system. If you never catch any oil, then you have no flow and that's about all you can say. If the flow is restricted, then how much is acceptable? I doubt you or I or BlazerLT, or for that matter anyone else here knows that.

All I can do is make you aware of potential problems that I see. I don't mind being corrected by anyone who knows more about a particular engine than I do. Such discussion adds to everyone's knowledge. In the end, it's your truck and you can do what you like to it. I just don't want people to go away from here partially uninformed.

[Brian R.]

Originally Posted by BlazerLT

If you have a bad restriction in this PCV system on this truck, you wil know it. The engine wil actually start to stumble and the idle rpms will fall low enough that the engine idle rather poorly.

If you want a test for that when you install this system, pinch the PCV hose between your thumb and index finger and you will hear the engine idle drop about 100rpms. You release and the idle sooths out perfectly.

Excellent - here is a way of telling if you have no flow. Now the $64,000 question that everyone should figure out is: How much flow restriction is acceptable and how much is harmful to your engine?

This is not important only if the filter never gets plugged further than it is when freshly installed. If it gets more and more plugged, you have a problem that is different for each engine.

[BlazerLT]

Originally Posted by Brian R.

Excellent - here is a way of telling if you have no flow. Now the $64,000 question that everyone should figure out is: How much flow restriction is acceptable and how much is harmful to your engine?

This is not important only if the filter never gets plugged further than it is when freshly installed. If it gets more and more plugged, you have a problem that is different for each engine.

Easy really, check your idle rpms, if it is in the range, you are fine. If it was plugged your engine will idle low.

Also, there is proactically no chance that an liquid will plug this coarse filter. Only solids will.

[BlitzKeg]

yea, I would'nt recommend this to anybody who has a problem with keeping up there car maintence.

If your pcv filter became clogged it can cause oil leaks from seals and/or gaskets due to high crankcase pressures.


besides the blow-by, fuel, and moisture from the crankcase actually helps the combustion process by improving drivability and performance.

Its normal for automobiles to have some oil comsumption. just aslong its nothing big.

If you suspect your valves be clogged, just use a top end engine cleaner.


the way I see it, if it works fine why f*** with it?

[BlitzKeg]

oh yea a good way to check ur pcv valve is to either take it out and shake it,....
its normal for the valve plunger inside the valve body to make a rattle,,....no rattle bad valve.

or you can use a suitable tool to pinch the pcv valve hose while the engine is at idle,..
there should be a change rpms when u pinch and u may hear a clicking noise when releasing and pinching the hose.
No change in rpms or no click means bad valve.

[BlazerLT]

Try it if you want, but I don't think blowby gas is good for the driveability.

Our engines are only made to recycle this back into the intake for emmisions and environmental purposes, NOT to make the engine run better.

[Brian R.]

It's good that you can see restriction in your truck. I don't know how good an indicator this is for others with either the same or different engines.

Thanks for attempting to answer my questions.