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

[BlazerLT]

Originally Posted by 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.

I hope you are not upset with me. =(

Ah, the $64,000 question you mean, it sounded more like a statement, not something youwanted me to answer directly.

You know what enough flow is, it is enough that the idle is exactly the same as before when it was not installed.

The MAP pressure sensor will tell you that for sure and does the measurements for you by controlling the vacuum in the intake.

If my idle is the same, then the flow and vacuum must be the same right?

Either way, you are removing the PCV gas out of the crank seeing if you didn't have enough flow, you sure wouldn't be bringing enough vapour into the separator to cause that amount of oil to collect.

But honestly, I installed it as many other have and suffered no problems whatsoever over 1000s of miles worth of direct evidence.

I understand you point but nothing is exact science like you seem to want it to be.

Example

- Do you think the difference in airflow from a cold air intake might hurt the engine?
- Does a high performance muffler reduce backpressure and does that hurt the exhaust valves?

Do we have any hard evidence saying that these tow things might in the long run cause harm to our engine? Not really....

But they sure will help which is exactly what this mod does. If it was a problem or it caused potential damage, you wouldn't think the diesel industry would use it in their industrial applications because I know my father's construction equipment has it.

Most of his equpment is 10-20 years old and working just fine.

Most of the mods on the market don't have the hard tested evidence you are asking for Brian.

[Brian R.]

Upset with you? No never. The only way I'd be upset is if you refused to discuss it and called me some kind of asshole for asking questions. You always attempt to answer question and do a really good job in that regard.

I don't expect answers to all the questions perfectly. I want answers to as many as possible. If you run out of science, it's not your fault. The systems are too damn complex. Once I know the limit of people's understanding of the system, I can give better recommendations on what to do and what not to do.

Getting that discussion on paper (more or less) is important for others to make up their mind about whether to adopt a mod or not. Saying "I've tried it and it worked for me" is not good enough for alot of engine mods. People need as much information as is available to provide the most critical of them to make an informed decision. Many mods are so simple in their effect, this is not necessary. This mod your advocating is not simple in its effect on the crankcase ventilation over time.

If the "hard tested evidence" is not available, I can easily live with that. That's the way things normally are. I just want to know that it's not available and have it on paper for the reasons I've just cited.

Just to belabor one point. IMO, the lack of oil in the separator is too coarse of an indicator to show that flow has been reduced when and if the filter partially plugs. The reduction in flow may be critical to crankcase ventilation and oil life.

Those examples you provided are much more simple than the mod in question. They both only change airflow through the combustion chambers of the engine. The potential problem with the oil-separator is a reduction in crankcase ventilation when the filter partially plugs. That is much more complex a system (lubricating ability of engine oil over time with varying ventilation) and really difficult to predict, even in an engine you are extremely familiar with - much less the rest of the engines belonging to people who might read this forum.

Don't worry about me. I think I know my limitations.

PS I apologize if I've trashed your thread with nonsense. To me, it's important - I know it isn't to everyone.

[BlazerLT]

I appreciate your thoughts and you are right on the money.

But I wantd to firm up one point. The filter is on the outlet of the separator and fluid is unable to plug it. There is no relative solids coming through this system so filter plugging is practically non-existent.

The filter is extremely coarse and by the picture I showed earlier with is cut across the center, it is not a considerable restriction even when wet.

[herkyhawki]

This will mainly help high-mileage engines. Large amounts of oil are an indication of excessive blow-by due to worn piston rings. As the amount of blow-by increases, the velocity of flow through the PCV system increases. The faster-flowing air is able to keep more oil-mist particles in suspension, and therefore carries more oil mist through the PCV system.
One thing to keep an eye on is to watch for new leaks from your engine gaskets. Addition of this filter will increase the pressure that is acting on all the seals and gaskets in your engine.
With all things considered, it is probably a good idea IF the separator screen is always clean, AND you change your oil often.
Another indication of excessive blow-by or plugged/restricted PCV is prescense of oil in the breather inlet line (hose from air filter to valve cover).
When the amount of blow-by exceeds the amount that can flow through the PCV valve, the blow-by starts to flow OUT of the breather line, where it is sucked into the main air intake. If your intake butterfly is getting gummed up, this is why. So if the addition of this separator causes restriction, you should keep an eye on the breather hose for signs of oil.

[BlazerLT]

Originally Posted by herkyhawki

This will mainly help high-mileage engines. Large amounts of oil are an indication of excessive blow-by due to worn piston rings. As the amount of blow-by increases, the velocity of flow through the PCV system increases. The faster-flowing air is able to keep more oil-mist particles in suspension, and therefore carries more oil mist through the PCV system.
One thing to keep an eye on is to watch for new leaks from your engine gaskets. Addition of this filter will increase the pressure that is acting on all the seals and gaskets in your engine.
With all things considered, it is probably a good idea IF the separator screen is always clean, AND you change your oil often.
Another indication of excessive blow-by or plugged/restricted PCV is prescense of oil in the breather inlet line (hose from air filter to valve cover).
When the amount of blow-by exceeds the amount that can flow through the PCV valve, the blow-by starts to flow OUT of the breather line, where it is sucked into the main air intake. If your intake butterfly is getting gummed up, this is why. So if the addition of this separator causes restriction, you should keep an eye on the breather hose for signs of oil.

I understand what you are saying, but my friend just installed this on his 2004 Civic with 20,000 miles and he is already seeing collection after only 1000 miles. Honda's are known to really consume oil through the PCV system.

This system will NOT cause crankcase pressure. I just removed the hose connected to the PCV valve and stuck my finger over the hole and the suction was so strong it kinda hurt and left a raised area of skin that was sucked up the hole in the hose. I then removed the hose from the outlet side of the filter and again stuck my finger over the hole and was met with the same state with no real difference felt.

The filter in this setup is not a serious restriction in this system. The filter element is extemely thin and I wish you guys would go buy one and look instead of saying it is restrictive from your computer chair. There is no way a liquid can plug this small hollow porous filter element. It just won't happen.

As said earlier, I thought the same thing as you guys and cut the element off only to have to much PCV flow through causing the engine to perform and idle like I had a vacuum leak.

I will prove this by attaching a vacuum gauge sometime in the near future for you guys to show the relative small difference.

[ZL1power69]

LT, i just finished the install on my 95 jimmy 5 minutes ago. Took about 10 minutes to install. I started the truck and the idle was spot on. I also left the filter in. like u said, i looked at the filter and it is thin. I installed it similar to urs. i routed the hose coming from the pcv behind the accumulator and tucked it in between the ecm and the accumulator. How long did it take for u to notice contamenents in the separator? I am curious to see how this thing works on my 200,000+ mile engine. anyway, i'll get some pics up here ASAP. O and the total cost was about $30-$40. thanks to everyone for the info and i'll keep u updated on the system's performance.

[BlazerLT]

Shouldn't take long at all.

Remove the PCV valve with it hooked up and feel the strong vacuum still there. You can reference me as to just how strong this vacuum is.

[ZL1power69]

Originally Posted by BlazerLT

Shouldn't take long at all.

Remove the PCV valve with it hooked up and feel the strong vacuum still there. You can reference me as to just how strong this vacuum is.

i just did what u told me to do. yes the vacuum is very stong and it does hurt after a while. just as i put my finger over the hose, the engine started to bog down. let off and the idle rises somewhat. plug the pcv back in and normal idle resumes. i guess this means the system is working well.

[Brian R.]

Originally Posted by BlazerLT

I understand what you are saying, but my friend just installed this on his 2004 Civic with 20,000 miles and he is already seeing collection after only 1000 miles. Honda's are known to really consume oil through the PCV system.

This system will NOT cause crankcase pressure. I just removed the hose connected to the PCV valve and stuck my finger over the hole and the suction was so strong it kinda hurt and left a raised area of skin that was sucked up the hole in the hose. I then removed the hose from the outlet side of the filter and again stuck my finger over the hole and was met with the same state with no real difference felt.

You are confusing vacuum (a presure measurement) with air flow (a mass transfer measurement). They are two different things. Your finger stopped the flow and measured the vacuum available. This vacuum is available anywhere in the system and is independent of the opening. Flow is dependent on the diameter of the opening and the difference in pressure between the two sides of the opening.

This is analogous to measuring normal fuel pressure and assuming your fuel filter is OK. You have to measure fuel flow to see if the fuel filter is plugged and you are starved for fuel. Vacuum is a static measurement. Flow is dynamic.

[BlazerLT]

Originally Posted by Brian R.

You are confusing vacuum (a presure measurement) with air flow (a mass transfer measurement). They are two different things. Your finger stopped the flow and measured the vacuum available. This vacuum is available anywhere in the system and is independent of the opening. Flow is dependent on the diameter of the opening and the difference in pressure between the two sides of the opening.

This is analogous to measuring normal fuel pressure and assuming your fuel filter is OK. You have to measure fuel flow to see if the fuel filter is plugged and you are starved for fuel. Vacuum is a static measurement. Flow is dynamic.

Yes, but if there was a restriction there wouldn't be any vacuum or very small flow.

There is a lot of vacuum and flow here and we both have seen it and experienced it.

[drdd]

doesn't the pcv valve control airflow (mass) by how far it opens? At low idle, blowby is not strong which means the pcv valve will only open slightly. Under heavier engine load, the blowby is greater and the pcv opens wider allowing more airflow (mass) to go thru.

Thus, if vacuum is normal (as determined by MAP and idle), then the PCV is under normal conditions / circumstances to do its job controlling the (mass) ... ???

also, if the blowby is so strong that the pcv cant allow ALLl blowby to escape (or perhaps the catchcan filter is slightly dirty) then the excess goes back thru the breather hose? is that right?

seems like changes in airflow (mass) caused by a filter (gradually over time becoming saturated) would be compensated for at the PCV valve.

thoughts ??

Originally Posted by Brian R.

You are confusing vacuum (a presure measurement) with air flow (a mass transfer measurement). They are two different things. Your finger stopped the flow and measured the vacuum available. This vacuum is available anywhere in the system and is independent of the opening. Flow is dependent on the diameter of the opening and the difference in pressure between the two sides of the opening.

This is analogous to measuring normal fuel pressure and assuming your fuel filter is OK. You have to measure fuel flow to see if the fuel filter is plugged and you are starved for fuel. Vacuum is a static measurement. Flow is dynamic.

[Brian R.]

Originally Posted by BlazerLT

Yes, but if there was a restriction there wouldn't be any vacuum or very small flow.

That's not correct. As long as there is any flow (and no leaks), you will get the same vacuum as with high flow. That's my point.

[Brian R.]

Originally Posted by drdd

doesn't the pcv valve control airflow (mass) by how far it opens? At low idle, blowby is not strong which means the pcv valve will only open slightly. Under heavier engine load, the blowby is greater and the pcv opens wider allowing more airflow (mass) to go thru.

Thus, if vacuum is normal (as determined by MAP and idle), then the PCV is under normal conditions / circumstances to do its job controlling the (mass) ... ???

also, if the blowby is so strong that the pcv cant allow ALLl blowby to escape (or perhaps the catchcan filter is slightly dirty) then the excess goes back thru the breather hose? is that right?

seems like changes in airflow (mass) caused by a filter (gradually over time becoming saturated) would be compensated for at the PCV valve.

thoughts ??

The PCV valve only controls the direction of flow (a check valve), not how much is flowing. It is not a variable valve, only an on-off valve.

What you said about the strong blowby is pretty much correct.

[drdd]

yup, I just got to thinking ... its not a spring loaded valve ...

got it.

Originally Posted by Brian R.

The PCV valve only controls the direction of flow (a check valve), not how much is flowing. It is not a variable valve, only an on-off valve.

What you said about the strong blowby is pretty much correct.

[drdd]

http://gm-trucks.com/IAR_pcv.shtml

fixed-orifice VS valve style?????????????


thoughts ?

would changing over to the fixed-orifice (kinky) do the same thing as the catch-can? are these on late-model trucks?

Originally Posted by Brian R.

The PCV valve only controls the direction of flow (a check valve), not how much is flowing. It is not a variable valve, only an on-off valve.

What you said about the strong blowby is pretty much correct.