Catch Cans - Ideas

[royster]

I recently heard about "catch cans"...they're sort of an air filter for the PCV valve vacuum. They keep crankcase gunk from going into your intakes. More and more, I see the benefit of doing this.

At present, I'm scratching my chin thinking HOW I want to do this. Forum input will benefit everybody.

Redneckmoparman offers a starting point with this website:

http://forum.2gn.org/viewtopic.php?t=9377

[royster]

Here is the simplest design I can think of. Using literally a jar, sealing the lines in and out, and loosely filling 1/2 to 3/4 of the jar with cheesecloth.

Any reason why this wouldn't perform the task of filtering gunk and trapping moisture?

8112

[royster]

Ill make one of these and let you know how it turns out.

[camoit]

The PCV is there to reduce moisture in the engine. With out it you will have moisture in the crank case. That was always a big problem with the old type 1 VW engines. I can't remember how many time my dip stick would be coved with white foam.

[Redneckmoparman]

i would add a drain to the bottom of the jar and fill it with steel wool or an aluminum version to avoid rust

[royster]

I appreciate the input.

There is some smog-related black canister on the fender...the parts truck has one, complete with a holder. (According to the service manual, it has charcoal in it). I'm going to see how that can be frankensteined into a viable catch can. I think that with duct tape, anything is possible. It's a metaphysical fact that certain areas of the universe ARE held together with duct tape. Quantum physics proves it, and quantum mechanics work on Hondas. (They won't work on a Stratus, though, because they're afraid of them. It's known as a "Stratus Fear").

[pennyman1]

that is the evap canister - I guess I don't understand why you just don't buy one made - they aren't that expensive and they will probably work better without bad possible issues if they aren't made right

[royster]

I guess I don't understand why you just don't buy one made

THIS, coming from Geronimo's creator! :)

[Merrill]

I don't know how to put this without trying to sound like I'm making a pitch here, but we manufacture catch cans as part of our product line.

Only catch cans, are meant to be catch cans. There is a separation and filtering process that needs to take place to keep the ventilation high and the crank waste low as well as out of the engine.

Here is an example of an empty "Universal catch can" can vs a real catch can

81238124

Here's the thing - YES proper purposed catch cans will keep the crank waste out of the engine and allow the crank case to breathe better. However, they are not going to do anything for you if you don't actually need one, other than adding bling. If you have no serious mods, you don't need one. The factory system will do just fine and regular maintenance will keep the vented crank waste from harming anything. Simple things like fuel cleaners (I like BG44k personally), and intake cleaners will wipe all that stuff away and all you need to do is dump it in the tank or spray it.

If you use a makeshift can, or an empty "universal" can, you run the risk of clogging your ventilation system, restricting it, or even worse, storing oil and moisture that is un-contained (slosh). If you use a recirculating ventilation system, you run the risk of letting your engine take a giant drink of crank waste if you let it slosh around. That's worse than the factory recirculating system.

Some re-circulation type catch cans of the "Universal" variety (like eBay) have ports that are actually smaller than your factory system. This is also worse than the factory system because you are taking a restrictive system (compared to performance systems) and restricting it even more. They are also empty cans, many of which can't be opened to be baffled.

8125

Just some food for thought. I can answer just about any question you have about this subject.

[royster]

No, you've answered very informatively, and it's what I needed to hear. I thank you!

[4doorciv]

http://i3.photobucket.com/albums/y66/4doorciv/E8FF3247-9331-461E-8F25-4AAA629E45FB-1630-000000DF6D547BDE_zps5c395ecb.jpg

Drilled a hole in my intake and added a barbed fitting. Connected a silicone hose from the can to the intake. It's a mishimoto catch can bought on Amazon.

[Merrill]

I'm confused... Are you talking about the intake to the turbo? From the looks in the pic, you have a hose going to the air intake which does absolutely nothing.

[camoit]

One thing you should know if you live in a state that you must pass a SMOG then do not change the way things are. A breather box or catch can as Merrill shows above is for a performance engine. You mush have a closed system or you will fail smog. Use of one of the items above will fail your test. Because it is an open system. As for crankcase gunk going into the intake it's not much. An engine can eat a lot of things. I have seen them eat a finger up to the first knuckle and nothing happened. We tore the hole thing down looking for the finger but it was gone. Snowmobiles don't have air cleaners but they do have a closed breather system.
As for the charcoal canister. It is built catch fuel tank vapors and allow them to be vented into the air cleaner to be burned at a cruse. Solid fuel will be returned to the tank. But I have never seen that happen. Because on the tank there is a separator with a check valve to stop fuel from making it's way to the charcoal canister.

[BradMph]

I don't know how to put this without trying to sound like I'm making a pitch here, but we manufacture catch cans as part of our product line.


Hey Merrill on those catch cans your selling with the material inside, what is the material (filtering product) that is contained in the canister?
Also I would imagine that the material is replaceable so when it gets clogged with collection of the crank case stuff. (if I'm correct)


I think some also use the catch can to catch the heavy materials that fall in from the case and though having baffles is a great idea to stop the direct return flight into the motor, most the heavy material will drop to the bottom of even an empty canister and not be sucked back. I agree on the restriction, if your restricting the line flow through a fitting or hose, this is not a good idea.
I use one on a car I have and it seems to work very well being empty. I'm not sure if it is fluke thing, but it's doing the job.
I also am exempt from any smog requirements due to vehicle year fall off.

[royster]

I'm glad this topic took off, because there's lots of great information here from people who know. As an added bonus, we get to learn about the charcoal canister.

My original thought for the catch can idea was to prevent excessive oil beads and blow-by from getting sucked into the engine and contributing to visible smoke...probably a "sky is falling" view on my part, but without facts, the human mind creates some unreasonable stuff and considers it possible.

From what I've been given on this thread, the standard system I have is good enough for stock performance. (An inspection of the PCV lines revealed no excessive oil sucking). Having spent a good amount of time cleaning out the plenium, my "fears" seemed justified. Then again, I corrected the original problem, so that shouldn't be a problem anymore. It was a concern that the PCV line is a down-hill, short shot into the plenium.

There's also a good chance the engine is still burning off Seafoam and residual oil from the exhaust system. After I run the vehicle on the road for a while, I'll have a better idea what's going on (or the problem will disappear).

Meanwhile, many thanks for the input from members who know.

[Merrill]

You mush have a closed system or you will fail smog. Use of one of the items above will fail your test.

California smog is mid evil to say the least lol. However, the bottom pic I posted is for re-circulation style systems (closed). All it does is filter the crank waste, and send the air back in. Many of our California clients use this system exactly for that reason and none of them have reported a failure because of it. The atmospheric type (with the filter on top) will fail a California smog right off the get go.



Hey Merrill on those catch cans your selling with the material inside, what is the material (filtering product) that is contained in the canister?
Also I would imagine that the material is replaceable so when it gets clogged with collection of the crank case stuff. (if I'm correct)

Gravity is the filter. The baffling and chambers of our system allow gravity to do its job (separate the crank waste from the air). There is a ton of R&D, engineering and live product testing that went in to these. They took over a year to develop. The main reason they took so long is they are a sealed, lifetime use product that never needs filter of baffling to be replaced. You simply wash them out during normal service intervals. You can use products such as brake parts cleaner, de-greaser, detergent, or just tip it over to dump the crank waste out. If the baffling ever does fail for whatever reason, it is covered under warranty.


The other part of this is the factory ventilation system. Yes many systems will line the intake manifold and CC's with gunk. They technically were meant to do that. The combatant to that problem is regularly scheduled maintenance. Catch cans are primarily for performance engines. Relieving excessive crank pressure is a modification that produces results (like installing a cold air intake is a modification). Unfortunately it also produces excessive crank waste (oil and moisture). Many race engines remove their baffling which allows more airborne crank waste to escape. The last thing you want to do is send all that crap back into the engine - especially an engine with a lot of performance mods. The catch can is the solution to the problem.

[4doorciv]

I'm confused... Are you talking about the intake to the turbo? From the looks in the pic, you have a hose going to the air intake which does absolutely nothing.

I have 2 vents on the valve cover. One has a check valve and goes the the intake manifold. I have theory her vent that is supposed to go to the intake pipe, that hose is routed to the catch can you see in the pic. Other end that is open see in pic, goes to the intake pre turbo.

[noahwins]

Catch cans work well on turbo applications. No point on a street car other than as an underhood farkle. A better solution might be to clean the PCV valve with carb cleaner and change it for a new one if it gets clogged. They cost around $3. If you see a lot of gunk building up around the PCV or any oil dribbling out, clean it or replace it. Also pull the breather hose off and make sure it's clean.