Redesigned Breather Setup

[VETTE_50_TH]

I know that there has been many articles about how to properly setup and not setup the Crankcase breather. And many heated battles have followed those articles. But i didnt see anyone make a setup like this. http://www.dsmtuners.com/forums/attachment.php?attachmentid=73164&stc=1&d=1177706248
redesigned catch can.bmp

Just let me know if that would work or not. I would have to cut a hole in the intake and put some type of fitting on it, but, logically, its very similar to a stock setup, but with the fact that its going to prevent oil into the nice shiny intake.

Thanks

James

 

[romeen]

Since there isn't any connection to the IM it will not provide for any significant ventilation when the intake is under vacuum.

 

[VETTE_50_TH]

So, if there was a T fitting after the catch can, which would go to either the IM or the intake, that would be better? Isnt the setup on a stock 1g go directly from the intake to the valve cover though?

 

[romeen]

I haven't given it a lot of thought but if you tee into the line between the catch can and VC (I think that's what you mean) then under boost you would have a blast of pressurized air being injected into the intake pipe at a right angle to the incoming air. I would speculate that this would cause a lot of turbulence possibly affecting performance.

In addition some of the metered air that is headed into the combustion chambers is going to get diverted back into the intake pipe when under boost. Even though it's being reintroduced after the MAS it may still affect A/F ratios. I'm not positive about that but it seems possible since your taking away a metered amount of air out of the equation at the last second.

But if you would be running a line to the IM anyway then just use the PCV and run a catch can inline with that. If you do this you must use a check valve between the IM and the catch can to avoid pressurizing it when under boost.

Both 1G and 2G cars run a line directly from the VC to the intake pipe.

 

[daren_p]

Am I missing something or are you just installing a catch can inline between the valve cover & intake? If so this is nothing new, this is what is recommended to keep a stock style setup but eliminate the mess in you intake/IC setup. You want the catch can sealed as well. I know this setup has been mentioned many times because I'm one of the ones who recommends it in these type of threads (& ofcourse Oldman ).

Romeen, Im not following your train of thought. Unless Im reading it wrong he's just adding a catch can inline with the crank case vent & he is leaving the factory PCV setup as stock? If so it obviously operates in the same way the stock system does & there won't be any pressure coming from the crank case vent under boost conditions.

 

[oldman]

romeen is getting old.

 

[romeen]

But i didnt see anyone make a setup like this.

This statement led me to believe that he couldn't be talking about simply running an inline catch can. I ASSumed there must be something else that he was looking at doing. So I took his diagram literally for the fact that it does not show any provision for the PCV valve.

James, you need to get back in here and back me up if I did understand you correctly otherwise Bruce won't let me live it down for awhile.

If I'm right then at them.

romeen is getting old.

Don't remind me.

 

[dsm-onster]

It was Bruce that pointed me to this thread. It's everything you need to know to have the best running PCV/breather system.

Stupid PCV question

Great reading.

 

[VETTE_50_TH]

i have a new intercooler pipe with the translator. i got the dejon tool intake pipe. I want to set it up similar to the stock setup by making a VC to intake, but adding a catch can in between so i dont get oil in my new turbo. Thats all. It seemed kinda logical, but must people dont want to cut a new hole in their brand new intake pipe, but since i got my dremel, i love cutting shit. . I thought my picture sorda explained that. I hope this is making sense now?

James



Thanks for the input guys. I love seeing people battle.

 

[Rice Over Wheat]

I have my valve cover breather vented to the bottom of the car. I don't see any point to recirculating that back into the intake. I can see why people with SMIMs may do this because they don't have PCVs anymore, but not if you have a stock intake manifold.

 

[oldman]

I have my valve cover breather vented to the bottom of the car. I don't see any point to recirculating that back into the intake. I can see why people with SMIMs may do this because they don't have PCVs anymore, but not if you have a stock intake manifold.

I would have expected this from some newbie but definitely not from you Kevin.

 

[Rice Over Wheat]

This is being discussed on dsmlink forums right now as well and nobody has been able to give me a satisfactory answer as to why you must recirc the crankcase pressure back into the intake. The only arguments I've heard in favor of it so far have to do with using the turbo to draw excess pressure out by recirculating back into the intake, and also in order to be environmentally conscious.

My thoughts are that since the pressure is sufficient to move on its own, hence it being pressure, the turbo isn't needed to help. And as for being better for the environment, I eliminated all my emissions and have no cat anyway. I know other people with dsms more built than mine who also just vent through a tube to the ground. And as for me, I have no ill effects from doing this. I'd really like to know why this is required because it sounds like people are saying it's an air metering issue or something?

And btw, we all have things we need to learn about.

 

[oldman]

This is being discussed on dsmlink forums right now as well and nobody has been able to give me a satisfactory answer as to why you must recirc the crankcase pressure back into the intake. The only arguments I've heard in favor of it so far have to do with using the turbo to draw excess pressure out by recirculating back into the intake, and also in order to be environmentally conscious.

My thoughts are that since the pressure is sufficient to move on its own, hence it being pressure, the turbo isn't needed to help. And as for being better for the environment, I eliminated all my emissions and have no cat anyway. I know other people with dsms more built than mine who also just vent through a tube to the ground. And as for me, I have no ill effects from doing this. I'd really like to know why this is required because it sounds like people are saying it's an air metering issue or something?

And btw, we all have things we need to learn about.

Kevin, air metering issues aside, the problem with your way of thinking is that you think crankcase ventilation is all about relieving crankcase pressure when in reality, pressure relief is only half of its intended purposes, IMO the less important half. What you're neglecting is VENTILATION, the removal of harmful contaminates resulted from blowby to prevent contamination of your oil which requires vacuum in the ventilation system, this is where both PCV valve and breather comes in. This topic has really been beaten to death and I'm surprised you have not read one of many threads on this topic, even members on DSMTalk have started to take notice on the importance of keeping both PCV and breather properly re-routed in the stock formation. Instead of retyping everything, I will just copy and paste what I posted in the past, I'm sure Daren and romeen would have more to add as both of them have become stronger/better advocates of the stock crankcase ventilation system than I.

For a PCV system (both PCV vavle and breather) to work effectively in ventilating the crankcase, they must work together as a team. While the system is under boost, PCV closes and ventilation is done through breather via vacuum in the intake pipe. While the system is under vacuum, PCV opens to relief pressure but more importantly, to remove blowby/contaminates from the crankcase then replace with fresh/metered air pulled in through the breather, this is the second part of crankcase ventilation that most seems to ignore, most only focuses on pressure relief.

Possible problems with other options:

1. Keeping PCV intact while venting the breather: Most running this setup will experience excessive crankcase pressure when under boost due to lack of vacuum coming from the intake pipe which can lead to dipstick pop out, leaky valve seals, tubo seal and gaskets. Less importantly, your AFR will go slightly leaner due to unmetered air.

2. Venting both PCV and brether: Pressure relief is not as big of an issue (provided that pcv is replace by a straight fitting) but because vacuum is completely removed, there are no ventilation and most blowby and contamintes will end up in your oil system. Less importantly your AFR will go slightly richer due to disabling the pcv vavle. Not a big problem for a track only cars but a DD is a different story.

You can easily maintain the integrity of your pcv system while keeping your intake tract clean as well as addressing the known leaky OEM PCV.

PCV side : IM -> heavy duty check valve -> inline/sealed catch can -> PCV valve -> VC

Breather side : VC -> 2nd inline/sealed catch can -> intake pipe

Furthermore, it's unfair that people on this side of the fence are always asked to justify our theories, let's turn the table around, what are your reasoning and the benefits of venting your crankcase ventilation system besides "because I see others do it all the time"?

 

[romeen]

Kevin, if the hose is long enough to reach the bottom of the car then what you have setup is basically a road draft tube which is what all cars used to ventilate the crankcase before the advent of the PCV system (it's at least better than just a filter on the VC breather). The idea being that the airflow across the end of the tube while the car is in motion would create a little vacuum thus pulling blow by out of the crankcase. This does work to an extent but the question should be is it preferable or better than the stock configuration?

In my opinion it wont be as effective as a connection to the intake pipe in a TURBOCHARGED car. Although I don't know what kind of velocities the incoming air reaches when under boost I would be willing to bet that it is considerably more than any speed that your car will typically see while driving. More velocity=more vacuum effect. Of course the main downside to this is the oily buildup (which can be nearly negated with a catch can) as well as some contamination of the air charge leading to slightly less efficient combustion (probably not enough to make a significant difference unless you are racing professionally). The ideal system is of course a seperate vacuum pump but cost, space, added complexity and legality makes this not very practical for a DD.

As Bruce mentioned removing blow by gases which can get absorbed into the oil and form acids and other corrosive substances which break down the oil is the most important function. Not adequately removing these leads to a vicious cycle. The more the oil breaks down the more cylinder wall scouring you get. The more cylinder wall erosion the more blow by you get and on and on.

I can tell some personal experiences and you can draw your own conclusion. Over the years I have had:

1) Just a breather filter on the VC
2) Filter at the end of a hose
3) PCV disabled with both VC fittings leading to a vented catch can (RRE method)
4) And for the past year the stock configuration with the addition of sealed catch can and check valve.

Over the years of doing the first three methods my oil would come out looking very dark, thin, and smelling really nasty. Since going back to the stock configuration my oil comes out looking quite clean with good lubricity remaining and not smelling like something that belongs in a military bio weapon or something. And I just use regular (petroleum) Valvoline 10-30....nothing fancy at all. Again, draw your own conclusions.

 

[Rice Over Wheat]

Oldman and Romeen, I have read dozens of threads on this topic and that is the first logical explanation I've read on the topic. In fact, now I think I know why I've been suspecting I may have leaky valve seals.

If that isn't in the FAQs then it should be. Sometimes things get lost in all the noise. That explanation is what I was asking for originally in the thread. I guess I'll do this mod next. Thanks for the info.

 

[romeen]

No problem Kevin.

Let's not bother Bruce. He's watching Lawrence Welk reruns.

 

[oldman]

Let's not bother Bruce. He's watching Lawrence Welk reruns.

I had to google that!

Kevin, now go and educate your brothers on Link.

 

[turbo addict]

Kevin, if the hose is long enough to reach the bottom of the car then what you have setup is basically a road draft tube which is what all cars used to ventilate the crankcase before the advent of the PCV system (it's at least better than just a filter on the VC breather). The idea being that the airflow across the end of the tube while the car is in motion would create a little vacuum thus pulling blow by out of the crankcase. This does work to an extent but the question should be is it preferable or better than the stock configuration?

In my opinion it wont be as effective as a connection to the intake pipe in a TURBOCHARGED car. Although I don't know what kind of velocities the incoming air reaches when under boost I would be willing to bet that it is considerably more than any speed that your car will typically see while driving. More velocity=more vacuum effect. Of course the main downside to this is the oily buildup (which can be nearly negated with a catch can) as well as some contamination of the air charge leading to slightly less efficient combustion (probably not enough to make a significant difference unless you are racing professionally). The ideal system is of course a seperate vacuum pump but cost, space, added complexity and legality makes this not very practical for a DD.

As Bruce mentioned removing blow by gases which can get absorbed into the oil and form acids and other corrosive substances which break down the oil is the most important function. Not adequately removing these leads to a vicious cycle. The more the oil breaks down the more cylinder wall scouring you get. The more cylinder wall erosion the more blow by you get and on and on.

I can tell some personal experiences and you can draw your own conclusion. Over the years I have had:

1) Just a breather filter on the VC
2) Filter at the end of a hose
3) PCV disabled with both VC fittings leading to a vented catch can (RRE method)
4) And for the past year the stock configuration with the addition of sealed catch can and check valve.

Over the years of doing the first three methods my oil would come out looking very dark, thin, and smelling really nasty. Since going back to the stock configuration my oil comes out looking quite clean with good lubricity remaining and not smelling like something that belongs in a military bio weapon or something. And I just use regular (petroleum) Valvoline 10-30....nothing fancy at all. Again, draw your own conclusions.

Which sealed catch can and check valve do you use,recommend?
I think that is one of the first intelligent explanations on the subject I've heard, thanks guys!

 

[romeen]

Which sealed catch can and check valve do you use,recommend?
I think that is one of the first intelligent explanations on the subject I've heard, thanks guys!

Since I already had a RRE catch can I just removed the filter off the top and capped it, but pretty much any sealed cc that you can fit into the engine bay should work. Mine is loosely stuffed with some filtering material to promote better removal/settling out of blow by gases.


This is the check valve that I and several others are using inline between PCV valve and intake manifold:

http://www.usplastic.com/catalog/va...ory_name=45&product_id=15641&variant_id=64175

Since you have to pay for shipping and they are so cheap you may as well order a few for DSM X-mas time.

 

[turbo addict]

Since I already had a RRE catch can I just removed the filter off the top and capped it, but pretty much any sealed cc that you can fit into the engine bay should work. Mine is loosely stuffed with some filtering material to promote better removal/settling out of blow by gases.


This is the check valve that I and several others are using inline between PCV valve and intake manifold:

http://www.usplastic.com/catalog/va...ory_name=45&product_id=15641&variant_id=64175

Since you have to pay for shipping and they are so cheap you may as well order a few for DSM X-mas time.

"Mine is loosely stuffed with some filtering material"-what are you using here? I know of some people using steel wool, if I try this I want to do it right.

Again thank you for the explanation.

 

[romeen]

I would not recommend steel wool. Since blow by contains water vapor it may cause the steel wool to rust and break down much quicker needing more frequent replacement. Copper pot scrubbers work well and are much more resistant to corrosion.

I ended up using some filtering material used in fish pond filtration. This was only because my dad had a bunch of it laying around so I snagged some. It's made out of nylon fibers so it definitley won't corrode. After you stuff and seal the catch can you should be able to blow through one fitting and have air exit out the other without difficulty otherwise it may be packed too tightly.

 

[nightspeed87]

I just used a 3 dollar fuel filter tapped between the intake pipe and head line. Works fine .
Ive seen a dsm valve cover recently were it was tapped for a second breather line therefore it had two
catch cans ran back to the intake hose, so id say double the effect.

 

[RedTurboEclipse]

I use to vent my VC breather to the bottom of the car, I was feeling some air/vac through the hose, I just gave in and recirculated it to the intake, and I gained 1hg vac?

 

[95blackGsTurbo]

I have found the best thing for me so far was to just cut the stock hose that goes from the valve cover to the intake and put an inline gas filter in there. Allows for plenty or air to flow and catches any oil that tries to get into the intake. Have run this setup on all 5 of my DSM's. Basically a 2.99 catchcan that looks pretty decent.

 

[blcknspo0ln]

I had to google that!

Kevin, now go and educate your brothers on Link.

Bruce you're going to kill me, but this is how I'm currently setup.

plugged PCV and filter breather on the VC. I can get a catch can, but I can't route back to the intake filter because my FP pipe isn't provisioned for it?