Oil Breather Tank instead of Catch Can

[Agentlongwood]

I've been reading a lot and watching a lot of videos about how catch cans operate and the purpose of the various lines in a closed system like the 3.5 Ecoboost.  It seems like a lot of it is more complicated than it really needs to be, for the sake of emissions.  That, coupled with the fact that even the highest quality catch cans don't stop all the gunk from going back into the intake, has led me to this conclusion; I'd like to try out the old hot-rodder setup of a breather tank like this one

https://www.amazon.com/Aluminum-Catch-Breather-Drain-Baffled/dp/B06XY938KV/ref=sr_1_7?ie=UTF8&qid=1503500846&sr=8-7&keywords=breather%2Btank&th=1

It's very similar to a catch can, but simpler.  Both ports on the tank are inlets, one for each valve cover.  No check valves, no connection to a vacuum source.  It's just a vent for positive pressure in the crank case, and a place for gunk to collect.  There is an internal baffle so it won't "puke" into the filter on top unless it's REALLY full.  Soaking the filter is one of the downsides to just sticking a breather filter on each valve cover.  This setup having no return line means absolutely zero contaminants are recirculated into the motor.  The motor gets only clean air, and nothing else.  This setup is also way cheaper than the high quality catch cans.  $60 plus fittings/hoses, instead of a $400 all inclusive kit.  While those $400 setups are a huge improvement, they still do allow a non-negligible amount of contaminant back into the motor, as shown by this guy who actually put them to the test: 

https://www.youtube.com/watch?v=IZYYdnwIEX0&lc=z131cvyxet2rxngru04ccniacvrdglspqeo.1495984962462811

Being that it uses a filter that is open to air, this means it is NOT a closed system so it would likely not pass emissions inspections.  Other than that, is there any huge drawback that I'm not seeing?  If I'm being a complete goofus and not seeing a huge downside, then I have no problem with someone pointing it out.  I'd actually prefer it, before I make a blunder.

 

[Macgyver]

Interesting idea.

I mean. How many emissions are we talking about here.

Will any vapors get stuff dirty in the engine bay that pass through the filter?

It wont effect the running of the motor/vacuum etc ?

 

[Agentlongwood]

As far as emissions it would be whatever the motor generates via blow-by, minus the amount that collects in the tank itself.  I do not have any specific numbers on an amount, though I don't imagine it would be a lot of volume. 

I do not believe it would get anything dirty in the engine bay.  I say that because some folks have run a breather filter on the front valve cover as part of a different setup, and they have not had issues with vapors getting things dirty.  I could be wrong though, since I do not have any first hand knowledge.

It should not affect the vacuum system in any way.  You will need to block off the port in the intake manifold that the PCV hooks into. (Or use it for meth/nitrous?) It would affect the running of the motor in a good way, by preventing deposits from accumulating on the intake valves.  Also, I've read that oil vapor lowers octane, but I do  not know if there is enough oil vapor recirculating in a healthy motor to make any significant difference.  Mostly I want to keep the intake tract (Valves, Turbos, CAC, etc) clean and free of the gunk that comes out of the crankcase. If there is a theoretical improvement in performance I won't complain, but I'm not holding my breath.

 

[sholxgt]

I'm no expert, but I think you'd be giving up a positive system (where vacuum is used to draw out the vapors) to a passive system where it would only vent.

I did this on a 5.0 back in the '90's and the vapors that came out of the filter were quite strong.  Car always had an oil odor.  Didn't care since it was a race car.  Not sure I'd want that in my Lincoln though.

 

[Agentlongwood]

It would definitely be a system where it would only vent vapors as opposed to actively drawing them out via  vacuum and fresh air supply.  I always thought that made it a "positive" system since it is relying on positive crank case pressure to vent the system...  I've been wrong before, so I wouldn't be surprised if it happens again, lol.

There is a fair bit of nuance to the factory system, which leads me to believe it isn't as effective at drawing out vapor as it would seem at first glance. Yes it has a vacuum source at all times, but without an inlet for fresh air that vacuum is only drawing out as much as blow-by generates, and no more.  The factory system has a source of fresh air only when not under boost. The front valve cover.  At idle the PCV connection gets vacuum from the manifold and fresh air from the front valve cover.  Under boost front valve cover becomes a source of vacuum, and the PCV  is closed.  So under boost there is no fresh air circulating, it is just a vacuum source being fed by blow by gasses and nothing else.

So vacuum, when coupled with fresh air source, does circulate more air through the crank case.  The downside is that it feeds the vapors right back into the motor, where it gums up the intake valves and pools in the CAC.  The breather tank would remove vapors at the rate they are generated via blow-by.  The positive pressure of blow-by gasses being what forces those gases and vapors out of the crank case.  None of it would be fed back into the motor though. 

As for smell, that certainly does suck...  I would think that an MKS would generate less than a 5.0 race car, but I've never tried so I don't actually know.  On your 5.0 were there just breathers fitted straight onto the valve covers, or were they routed to a breather tank?

 

[sholxgt]

I had baffled breathers on the valve covers.  No breather tank.  It was a mess that required regular cleaning.

I like that you're pursuing options.  In my mind, the advantage your idea has over a full blown catch can system is simplicity and cost.  The downside could be odor and worse polluting for the environment.

As for the 5.0 vs this 3.5 EB, it would not surprise me if this 3.5 isn't dirtier than a 5.0 with good rings and seals.  These do not seem to be overly clean judging by the oil pooling I get in the CAC.

 

[Agentlongwood]

For sure, simplicity, cost as well as 100% efficiency at preventing gunk from getting into back into the intake tract.  No more oil pooling in the CAC.

My "hope" is that using some tubing and a breather tank cuts down on the mess.  If the fluid has to travel that much further and pass through a tank, then "hopefully" it won't splash into the filter and cause a mess which will cut back on smell.

Who knows, it may be way worse than your old 5.0, lol.  I think this might be a situation where the only way to be sure it for me to try it.  As long as nobody points out some catastrophic failure that this would cause, I think I'll put something together and report back on it, in a week or two.  It may be a lesson that needs to be learned the hard way... Luckily it's cheap enough that I won't feel bad if it ends up a failure.

 

[sholxgt]

Mostly just a cost of time.  Figure the tank can be sold used to recapture some of the cost if the plan fails.

Good luck!!!

 

[Agentlongwood]

Well I pulled the trigger and ordered that 1 liter breather can.  I'm going to give it a try.  Once I get it hooked up and put some miles on it, I'll let yall know if it works out or not.  If nothing else, it should be an interesting learning experience.

 

[SHOdded]

Fingers crossed

 

[GIGANTORE]

Well I pulled the trigger and ordered that 1 liter breather can.  I'm going to give it a try.  Once I get it hooked up and put some miles on it, I'll let yall know if it works out or not.  If nothing else, it should be an interesting learning experience.

I replied to this topic in your other thread. I can appreciate you wanting to do something to address the crap these cars produce. But removing vac from the system will have you going in the wrong direction. Turbo engines run dirty. You need to have vacuum to remove it.

 

[Agentlongwood]

Removing vac from the system will have you going in the wrong direction. Turbo engines run dirty. You need to have vacuum to remove it.

What do you mean, specifically, by turbo motors run dirty?

 

[GIGANTORE]

Meaning that you are sucking those oil vapors back into the intake tract and through the turbo.

 

[Agentlongwood]

Meaning that you are sucking those oil vapors back into the intake tract and through the turbo.

Hmmm, I guess I'm not understanding something here.  I wanted to eliminate the source of vacuum specifically to prevent sucking vapors though the turbo and intake tract...  With a breather tank, the vapors are pushed out via positive crank case pressure, and condense in a tank, rather than using the negative pressure to suck them into the intake.  Don't get me wrong, I don't claim to know this stuff super well, lol.  Never done a catch-can or breather tank setup.  I would just like a system that feeds the motor 100% clean air instead of "mostly" clean air, that catch cans provide. 

 

[GIGANTORE]

Meaning that you are sucking those oil vapors back into the intake tract and through the turbo.

Hmmm, I guess I'm not understanding something here.  I wanted to eliminate the source of vacuum specifically to prevent sucking vapors though the turbo and intake tract...  With a breather tank, the vapors are pushed out via positive crank case pressure, and condense in a tank, rather than using the negative pressure to suck them into the intake.  Don't get me wrong, I don't claim to know this stuff super well, lol.  Never done a catch-can or breather tank setup.  I would just like a system that feeds the motor 100% clean air instead of "mostly" clean air, that catch cans provide.

The only way to do it without rerouting back through your intake is to collect the waste before it goes back through. So a catch can is your only way. Because crank case pressure is usually not enough to push all of it out. And once it leaves the valve cover it loses that pressure. That’s why it’s not suggested to just put a filter on there. The filter ends up getting soaked and presents a fire hazard. Vacuum is a necessary aspect of a good system.