Anyone Here Ever Use an Oil Catch Canister?

[EXCellR8]

These are not the same as Oil/Water separators found on boosted applications... but are similar in what they do

I see these in a lot of engine bays these days... a canister that is placed between the PCV valve and the intake manifold. To my basic understanding, they claim to trap any contaminants that could be floating around in the heated vapor that is released from the crank case--since piston rings are not 100% effective at keeping fuel, additives, and possibly water out of the block. The oil filter is, quite obviously, responsible to filtering out whatever is in the oil but the vapor is normally just routed back into the combustion chamber.

(it's the box with the little red filter)

I was reading a nice write-up on Radium Engineering's website but is something like this worth installing on something like a daily with retail fuel or would it be more suitable for something that is driven hard or for competition purposes?

As far as emissions go, it would seem that only "closed" systems are guaranteed to pass inspection whereas open ones (or ones that vent to atmosphere) may not depending on where you are. A lot of these systems I see put in place appear to be both though, or are connected directly to the valve cover. There are a lot of cheap ones floating around just from doing some searching but according to many sites only catch cans with filters/baffles will actually do anything.

Any input?

 

[zinfamous]

I've briefly considered getting one for the GTI but I probably won't. They are very popular for performance VWs and related because they do help to reduce the notorious carbon buildup, but no matter what you do, that is going to happen anyway, so those valves will have to be cleaned eventually.

On top of that, you do have to drain the thing from time to time and, I guess, top off your oil a bit more frequently? Seems like more hassle than it's worth as it doesn't prevent one of the main things you want it to prevent. I guess it might be worth it if really improves your engine life above some marginal level.

 

[jlee]

If you do get one, you definitely want baffles. A non-baffled catch can with a filter on top will just blow oil vapor all over the place. Recirculating into the intake with a baffled can is the way to go, IMO (if you do it at all).

 

[EXCellR8]

Yea I'm not so sure I buy into the whole "maximizing of octane" sell-up since we're just talking about blow by but I would just be in it for engine life/lasting performance if anything. If the Radium canister wasn't so darn expensive I'd just grab one for my FR-S because I like the design, placement, and how it features a little dipstick to check the level. Boxer engines are known for burning a little bit of oil though so I'd probably end up having to top off my oil more frequently, like zinfamous stated above.

Eh, kind of on the fence but more so leaning to just not bothering... $200 is way steep though.

 

[mindless1]

They are useful for GDI (only) engines. They are a waste of money for anything else.

 

[RLGL]

You are overthinking it. Spend your money on something else.

 

[Hail The Brain Slug]

They are useful for GDI (only) engines. They are a waste of money for anything else.

This is not true in some cases, as well. Look at Honda's 10th generation L15B7 GTDI engine - the plastic valve cover with integrated PCV valve routes the PCV through a snaking passage of baffles to runoff the oil back to the crankcase before recirculating.

As newer GDI platforms come out the engineers are starting to learn how to redesign the PCV system to accommodate the intricacies of GDI.

 

[mindless1]

^ We were talking about adding an aftermarket to an engine that doesn't have one.

A design that drains contaminated oil back into the crankcase does not seem like a complete solution. Separating it from the water does not make it as clean as the rest of the oil, especially if the engine suffers from fuel dilution.

At the same time, I could see an engine with that problem filling up a catch can faster. Trade off inconvenience of emptying it for a healthier engine? I'd want to change the oil on such an engine more often if not discarding it instead.

I would rather an engine without that problem, not one where they make it more complex and costly to repair later. "plastic valve cover with integrated PCV valve", no thanks.

 

[EXCellR8]

I would think the amount of actual oil escaping from a natural aspirated engine via PCV valve would be negligible; if not automakers would be replacing/servicing a LOT of engines. If you've got a turbo or super charger cramming air and fuel into the motor and there's just more overall pressure, then something like this in conjunction with a AoS would be more advisable. That takes much more into consideration anyway though; in a lot of cases the health of the engine (if not properly set up) is void anyway.

Thanks for all of the input

 

[mindless1]

^ Amount of oil pulled is about driving conditions and vac level, turbo/super charging would affect piston blow by gasses, water, and fuel far more than oil vapor.

The main issue is neither, rather GDI gets valve deposits from the oil cooked on if not a more recent design with an additional port injector added upstream of the intake valves to clean them off and in some cases keep them a little cooler.

 

[dave_the_nerd]

 

[HarryLui]

I use a genuine Provent 200 on my Turbo Omni.
http://www.turbo-mopar.com/forums/showthread.php?83057-Provent-200-installation

 

[Hail The Brain Slug]

^ We were talking about adding an aftermarket to an engine that doesn't have one.

A design that drains contaminated oil back into the crankcase does not seem like a complete solution. Separating it from the water does not make it as clean as the rest of the oil, especially if the engine suffers from fuel dilution.

At the same time, I could see an engine with that problem filling up a catch can faster. Trade off inconvenience of emptying it for a healthier engine? I'd want to change the oil on such an engine more often if not discarding it instead.

I would rather an engine without that problem, not one where they make it more complex and costly to repair later. "plastic valve cover with integrated PCV valve", no thanks.

The reality is a lot of newer engines are being designed with a plastic parts - plastic valve covers, plastic intake manifolds, plastic cooling system hose mounts, etc. All of which can easily crack or have integrated components fail. I've had all three of these parts replaced under warranty on newer cars I've owned.

There's nothing wrong with draining the oil back into the crank case, so long as the water and fuel contaminants can escape to be circulated through the intake.

 

[bill1024]

I have a small oil separator like you would use on an air compressor and a brass check valve in line. That is connected after the PCV valve before it goes back into the intake plenum.
It keeps the intake plenum, valves and #4 ,#8 plugs clean and oil free.
302 the back plugs gets wet from the crap coming back in the intake. No more.
I empty it every couple of months. Some oil, water, not much, maybe an ounce or so.
The car is a 93 SVT Mustang Cobra, aluminum heads, cam and blower. 8# boost.

 

[mindless1]

There's nothing wrong with draining the oil back into the crank case, so long as the water and fuel contaminants can escape to be circulated through the intake.

You seem to be implying that's a 100% separation when it is nowhere near that, which makes it inferior, though less maintenance, to let the owner not deal with it but the engine has to.

There is no way to effectively get fuel contaminants out of the oil vapor. In a lab yes, in a PCV vehicle setup, not so much.

I don't take much consolation about parts repaired under warranty. I'm more concerned about the fact that they had to be replaced under warranty. It means in best case, of high cost OEM parts, you can expect it to fail again, or worse if an inferior aftermarket part, unless the aftermarket comes up with a solution. Sometimes they do, but often it's more about making the same part cheaper... maybe similar, even better quality, but undercutting the OEM price so there's a market for the part.

Warranty period is the part I hate about a vehicle, where depreciation is so very high. Plus, problems that cause repairs that early in the vehicle life, tend to tank the resale value of a vehicle.

 

[DrDoug]

I have a small oil separator

Same here on my 351W but I built mine. Regarding the picture at the top, that's a really horrible design for a PCV system. With that layout there is no fresh air going in to the crankcase. A better layout would have fresh filtered air going in one valve cover and the other cover connection going to the separator, then the separator being connected to the PCV at the intake.

 

[Hail The Brain Slug]

You seem to be implying that's a 100% separation when it is nowhere near that, which makes it inferior, though less maintenance, to let the owner not deal with it but the engine has to.

There is no way to effectively get fuel contaminants out of the oil vapor. In a lab yes, in a PCV vehicle setup, not so much.

I don't take much consolation about parts repaired under warranty. I'm more concerned about the fact that they had to be replaced under warranty. It means in best case, of high cost OEM parts, you can expect it to fail again, or worse if an inferior aftermarket part, unless the aftermarket comes up with a solution. Sometimes they do, but often it's more about making the same part cheaper... maybe similar, even better quality, but undercutting the OEM price so there's a market for the part.

Warranty period is the part I hate about a vehicle, where depreciation is so very high. Plus, problems that cause repairs that early in the vehicle life, tend to tank the resale value of a vehicle.

100% seperation in any system is contingent on sufficient time at full operating temperature to allow time for the contaminants to evaporate.

You're right in that the system I've described is less efficient - it takes more time at full operating temperature to evaporate contaminants. That's why Honda has the massive oil dilution scandal and that's why their "fix" only includes preventing the heater from working until the engine is at full operating temperature so it has more time to evaporate. It also has some remapping for cold start fuel injection since apparently there was a significant amount of blowby occuring before reaching operating temperature.

I'm not saying a catch can isn't a better solution for effectiveness, but air oil seperators that do not drain back into the crankcase are illegal in California and in every state that has adopted CARB regulations. OEMs will probably never use catch cans because of this, but they're definitely going to be engineering more advanced PCV systems for new platforms like Honda has.

Pretty soon most new cars will have something like this, an air-oil seperator that drains back into the crankcase. Everyone's implementation will be different and focus on different aspects. Honda went a bit too far toward the high speration at the cost of time to evaporate - they wanted their first mainstream TGDI engine to live up to their reliability standards and not require intake valve cleaning. Obviously that's bitten them in the ass because a significant amount of people don't drive long enough for that seperation system to allow sufficient evaporation.