what are the benefits of a breather?

[quachster858]

what are the benefits of having a breather instead of just the pcv

[myeverlovinsir]

I can't see the logic in your question. If you were to replace the pcv with a breather, meaning your postive crankcase vent would go to air instead of back into the intake manifold, your engine would react violently and not idle correctly. Your idle properties would be 1000rpm to 3000rpm and back. This would occur roughly every second. If you need to test this to see for yourself, start your car and remove the hose from your pcv going into the intake maifold. You will know what I speak of.;)

[02blksi]

FYI the crankcase breather and the PCV units are Two different pieces, The PCY is located to the left of the intake manifold and the breather is located on the valve cover. --Joe

[JSIR]

the stock system is precisely designed, throwing a breather filter on there can only make it worse, and there certainly aren't any benefits. A waste of money more than anything.

[chunky]

messing with stock breather system = bad.

the only modifications i deem worthwhile are the installation of oil chatch cans on the pcv & breather hoses.

[Gibhunter]

Breather filter is there to keep debris out of the engine and to let it expel blow by gases. The reason why it's connected to the air box is that blow by gases are considered emissions and letting them out into the airbox keeps them out of atmosphere. The reason companies like Injen or AEM design their intakes to accept the breather tubes, is because otherwise they would never be able to get their carb certification.

Simple as that. Don't let these uninformed domsayers tell you otherwise.

[JSIR]

so what is the actual benefit of running a breather filter at the end ouf our breather tube ? .

There certainly arent any hp benefits, I've tested that many times on a dyno. If someone else has found any hp from disconnecing that, I'd love to see it.

It doesn't keep your intake much cleaner as air primarily flows from the intake into the valve cover direction not the other way as the filtered air replaces air being sucked out of the crankcase. In some driving conditions you can get a bit of reversion in the other direction but it isn't much. Take your intake tube and box apart and see how much oil is in there, doubt you will find more than a drop. All the oil residue in the intake manifold and on the throttle body comes from the pcv valve system , thus the oil catch can idea is what works best. The pcv valve system is beneficial in sucking out crankcase vapours, although it takes some oil with the vapours.

[Gibhunter]

Oil catch can at least the way I understand it is not going to let air come inside, or allow gasses to escape the engine. Since Honda designed that opening to be there for engine ventilation, I don't believe that it's a good idea to have it blocked. Therefore in my opinion if you can't connect it to your intake, put a breather filter on it. That's what these filters were designed after all.

[fishboy]

i have one that i use to catch oil. i didn't want oil shooting into my CAI, but i've checked it a few times and there is no oil coming out of there. the reason mine looks so dirty is because is was off my friend's prelude, which shot lots of oil into the thing.

i don't think air is getting through so i might be hindering my car, but i can't tell. i think my car picks up nice. i'm having trouble finding a new one that will work. my breather has a metal rod coming out of it that fits in that breather tube.

http://www.digitalpose.com/mbr/1/9140/p/190464_3982160137247214869_vl.jpg

edit: found a better pic in my cpu

http://www.digitalpose.com/mbr/1/9140/p/199177_575563980740625591_vl.jpg

i say do it if you feel like it, no biggie either way.

[quachster858]

hey thanx for the help guys, really apreciate it:cool:

[FascistDictator]

"When it's not broken don't fix it." should have been the only answer you needed.

[chunky]

Originally posted by Gibhunter
Oil catch can at least the way I understand it is not going to let air come inside, or allow gasses to escape the engine. Since Honda designed that opening to be there for engine ventilation, I don't believe that it's a good idea to have it blocked. Therefore in my opinion if you can't connect it to your intake, put a breather filter on it. That's what these filters were designed after all.

oil catch cans are nothing more than charcoal canisters that draw evaporated oil out from the air passing through the cans.

Honda designed the breather system to feed air INTO the valve cover - not to allow gasses to escape through the valve cover.

The air flows from the intake INTO the valve cover, then down to the crank case, where it flows out via the PCV valve. It was designed as a system, it needs the positive airflow current created by the air intake velocity.

breather filters over time will lead to a motor that has poor ring seal and burns lots of oil - this holds true for hondas but not necessarily for other makes of cars.

so on hondas, a breather filter is a no go - hook it up to your intake directly or via an oil catch can.

[quachster858]

heh, i guess ill just leave it as is for now until i get a lil bit more car savvy, neways thanx for the input all

[JSIR]

Chunky you are exactly right about the workings of the breather and PCV system as designed by Honda.

If you install an oil catch can it should go between the crankcase and the intake manifold which is located on the passenger side of the intake manifold , there is a rubber tube that enters the intake manifold from just under the idler pulley. That is where 99% of the oil accumlation comes from, not the breather tube that attaches to the intake. If installed between the crankcase and manifold you will filter out the oil from the gasses without restricting the air flow to the pcv valve on its way to the intake manifold.

hth

[JSIR]

if anybody wants I can scan a pic of the pcv and breather tube workings from my shop manual, clearly showing the path of airflow between the different parts. Air is meant to flow from intake through breather tube into valve cover down to crankcase.

[Gibhunter]

Originally posted by JSIR
if anybody wants I can scan a pic of the pcv and breather tube workings from my shop manual, clearly showing the path of airflow between the different parts. Air is meant to flow from intake through breather tube into valve cover down to crankcase.

Ok. Then blocking the tube would not be a good idea. Also I don't buy what Chunky said. The air velocity created by the intake is created by the suction from the intake manifold. If you look at the way that tube connects to the airbox, you can see that there is no special cutouts in there channeling the airflow into that tube and airflow itself is not going to force air in there. It's only purpose is to either deliver clean, fresh air into the engine or to remove the blow by gases back into the system. And it certainly is NOT going to help the rings seal better. I read the article where you got that BS idea from. It's nothing but some amateurish BS. Don't believe everything that you read on the internet.

[chunky]

Originally posted by Gibhunter


Ok. Then blocking the tube would not be a good idea. Also I don't buy what Chunky said. The air velocity created by the intake is created by the suction from the intake manifold. If you look at the way that tube connects to the airbox, you can see that there is no special cutouts in there channeling the airflow into that tube and airflow itself is not going to force air in there. It's only purpose is to either deliver clean, fresh air into the engine or to remove the blow by gases back into the system. And it certainly is NOT going to help the rings seal better. I read the article where you got that BS idea from. It's nothing but some amateurish BS. Don't believe everything that you read on the internet.

If JSIR posts the diagram from the factory service manual of the pcv/breather system, it will show without any question that honda designed the system to circulate air INTO the valve cover, and not out as you believe.

I am not a professional mechanic by any means, but this isn't a b.s. idea, it's a well documented fact with honda motors. Read on endyn's site. Read the factory service manual, they all say the same thing, air goes into the valve cover via the breather hose.

And oil catch cans do NOT block airflow. If they did, do you think there would be a return line from the catch can? The air flows into the catch can, gets filtered, and then continues on it's merry way.

[Gibhunter]

Originally posted by chunky

Read the factory service manual, they all say the same thing, air goes into the valve cover via the breather hose.

I wasn't arguing about that. I was arguing about what you said about the breather filter possibly leading to loss of compression.

[fishboy]

shit. i'm taking my breather off. i didn't realize the breather would let air escape. i thought it would suck in. i don't want oil to get in my filter though.:(

[02blksi]

"oil catch cans are nothing more than charcoal canisters "

LOL charcoal huh??? This isnt a fish filter LOLOL

Oil catch can either have baffles inside them that catch the oil that escapes from the PCV (NOT THE BREATHER) or what most people do is they get a can and put some brillo pads in it so that it catches the oily air that passes through it.

A correctly installed oil catch can is installed with one end in between the oem pcv (rubber hose) and the intake manifold itself. I should know because i already have one installed on my car. Ill post a pic later if i can find it. The only time you will see a catch can attached to the Breather area, is in the case that the OEM PCV valve is bypassed with a blocking plate which totally eliminates the oem pcv and rubber hose going to the intake. But on an OEM setup ALL CATCH CANS GO FROM PCV --- CATCH CAN--- Intake manifold...

Just wanted to clear some things up .. --Joe. :)

[myeverlovinsir]

Found this pic of your catch can Joe...


http://ephatch.com/forum/attachment.php?postid=53999

I've been meaning to do this, but have been preocupado with other engine stuff. tks for the info.;)

[02blksi]

ahh yes thats it... thanks bud, -Joe :)

[chunky]

Originally posted by 02blksi
"oil catch cans are nothing more than charcoal canisters "

LOL charcoal huh??? This isnt a fish filter LOLOL

Oil catch can either have baffles inside them that catch the oil that escapes from the PCV (NOT THE BREATHER) or what most people do is they get a can and put some brillo pads in it so that it catches the oily air that passes through it.

most of the catch cans utilize activated charcoal that is spread out over the baffle plates inside the catch can. The charcoal catches much finer drops of oil, and prevents the oil from pooling and blowing back out.



A correctly installed oil catch can is installed with one end in between the oem pcv (rubber hose) and the intake manifold itself. I should know because i already have one installed on my car. Ill post a pic later if i can find it. The only time you will see a catch can attached to the Breather area, is in the case that the OEM PCV valve is bypassed with a blocking plate which totally eliminates the oem pcv and rubber hose going to the intake. But on an OEM setup ALL CATCH CANS GO FROM PCV --- CATCH CAN--- Intake manifold...

Just wanted to clear some things up .. --Joe. :)
you can install a catch can anywhere where you want to filter oil from the passing air flow. I agree that most often catch cans are utilized between the PCV valve and the intake, but some people use them between the breather hose and the intake to prevent any oil from coming out of the valve cover - it's very rare that air will flow in the opposite direction, but it does happen.

Why anyone would put a blocking plate over the PCV valve on a honda I do not know. The PCV system on hondas DOES promote better ring seal. over time, it's practically garanteed that a motor with a non functioning PCV system will being to have crazy oil blowby.

[SpeeDemoN]

I'm coming into this topic a little bit late, but I will tell you this much.

At first when i started fooling around with my air filter, i left a cone with a breather filter installed. At first, the car felt really sluggish, but after a while the bogging went away (or maybe i just got used to it).

When i got around to installing an intake pipe and removed the breather (connected the tubing to the opening on the intake pipe) I was amazed at how much better the car was, it was a night and day difference. It pulled so much stronger, and there was no bogging AT ALL. even at really low rpm, the car felt totally different.

I guess what i'm trying to say is, there are no advantages to having the breather, just a disadvantage.