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hey fellas, thanks for the help on my other post,we got it running right finally, anyways whats everyones opinion on a breather on the valve cover? is it bad for the motor? does it hurt anything? make a difference? or what? i capped mine off and capped off the nipple piece on my cold air intake. i was just told that it would hurt my motor, that it was bad for it. any other opinions?
 

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I've been using a breather filter for years. Never had a problem even with boost. You NEED to let the engine vent atleast. Running it back to the intake just helps the pressure escape quicker. Either way put the hose back on or a breather filter.
 

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Bizzar said:
I've been using a breather filter for years. Never had a problem even with boost. You NEED to let the engine vent atleast. Running it back to the intake just helps the pressure escape quicker. Either way put the hose back on or a breather filter.
To the original author, do not cap them off, you need that line there.

Also, it is a common misconception that the breather allows the engine to vent, but its the opposite, air is supposed to come in from the intake into the hole on the valve cover. Problem is there is not a vacuum on the head, so you need to cram air into it from the intake.

take a look at the helms manual for the pcv system. it has a diagram showing how air is supposed to flow through the system.

You need the line there and search on "slash cut tube"
 

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egSi said:
i used to have a filter now i got a oil catch can with a filter on top.

pimp IMO ;-)
you have a catch can going from the breather port on the valve cover? hate to tell you this, but you've got it in the wrong place. it should be connected :

breather chamber (on back of engine) -> catch can -> pcv valve -> intake manifold.
 

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i dont get it Kommon sense, how is air gonna enter the head when the intake port is under vacuum? That would be like puttin a vacuum in a balloon and sayin that the balloon is gonna fill with air. Correct me if im wrong.
 

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The intake is under vacuum, but air is flowing through the intake and past the breather tube right? Think about it like this... you have a stream and water flowing past you, now you stick a bucket into the stream and the stream fills the bucket with water... as long as the bucket is pointing in the right direction.. don't forget to search on "slash cut tube"

Here is the diagram of the pcv system and the way that air is supposed to flow through the system. click on the image to enlarge it.

http://www.redpepperracing.com/technical/143/agu
 

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For the catch connection, will this work??

breather chamber (on back of engine) -> PCV valve -> catch can -> intake manifold.

Please respond
 

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kommon_sense said:
The intake is under vacuum, but air is flowing through the intake and past the breather tube right? Think about it like this... you have a stream and water flowing past you, now you stick a bucket into the stream and the stream fills the bucket with water... as long as the bucket is pointing in the right direction.. don't forget to search on "slash cut tube"

Here is the diagram of the pcv system and the way that air is supposed to flow through the system. click on the image to enlarge it.

http://www.redpepperracing.com/technical/143/agu
Ok, I don't want to start a fight, but this sounds wrong. I read the link you posted, but I say BS. EVERYTHING connected to the intake system is in a vacuum (on a N/A car). It doesn't matter if you have a slash cut tube facing the right way to 'catch' the air as it goes by. It's the opposite. Think of a siphon. The air rushing over the tip of the tube creates a vacuum much like the way an airplane wing generates lift. The point of the breather hose is to recirculate blow-by gas that makes it's way to the valve cover. Take your oil cap off when the car is idling. You can feel distinct pulses of the blowby. If the point was to push air into the valve cover, where would the air go?

In any case, you don't want to plug that hole, it's there for a reason, you just don't have to run it to the intake if you don't want to. OEM connects the hose to the intake to burn off any oil vapors.
.02

-ic
 

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icarusdown said:
In any case, you don't want to plug that hole, it's there for a reason, you just don't have to run it to the intake if you don't want to. OEM connects the hose to the intake to burn off any oil vapors.
.02

-ic
I'm not sure how you can disagree with the pics that the honda engineers drew. The diagram clearly shows the flow of air through the system and it clearly shows that it was intended for air to go from the intake into the head. It does not show air flowing in the other direction.
 

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I've been here at Saturn for 8 years and we have seen literaly HUNDREDS of misprints and mistakes. I'm sorry I disagree if you pressurise the valve cover you are looking for trouble. The first thing that will happen is the front crank seal will go caput. Next inline is the valve seals and IF you are lucky the engine might survive. Try it, go for it put some pressure INTO your valve cover. The air flows OUT of the valve cover and it is supposed to. Air from the intake rushing over the breather tube will create a vacuum back into the intake out of the valve cover. N/A it is fine to disconnect the hose but you must leave some sort of venting on the valve cover to relive pressure. On a boosted car its a huge NO-NO to leave it connected as under boost it will pressurise the head and the entire oiling system.
 

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I'll go do some more digging on the topic. However every honda manual that I've looked at shows the same picture/setup.

Keep in mind that this is a small inlet tube and you won't really be able to pressurize the head/crankcase. The pcv valve is there to allow the crankcase to vent. So we have a way in and a way out.
 

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back to topic. UNCAP and attatch breather filters.
DONE!
 

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I've never worked on one, just stating what I see in the picture.

From the service manual, it looks like its the pressure difference between the two connections in the intake that make the gases move. The PCV valve is opened by manifold vacuum when the throttle is closed. The intake manifold has a much greater vacuum than the one created by the passing air over the vent tube, thereby causing the gases to move from the intake, through the vent tube, motor, out the PCV valve, and into the IM. When the manifold isn't at vacuum, like at WOT, the PCV closes, and any excess pressure that occurs may exit the vent tube (likely why it is not at an angle in the intake).

Just my guess.
 

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Ok, I don't want to start a fight, but this sounds wrong. I read the link you posted, but I say BS. EVERYTHING connected to the intake system is in a vacuum (on a N/A car). It doesn't matter if you have a slash cut tube facing the right way to 'catch' the air as it goes by. It's the opposite. Think of a siphon. The air rushing over the tip of the tube creates a vacuum much like the way an airplane wing generates lift. The point of the breather hose is to recirculate blow-by gas that makes it's way to the valve cover. Take your oil cap off when the car is idling. You can feel distinct pulses of the blowby. If the point was to push air into the valve cover, where would the air go?

In any case, you don't want to plug that hole, it's there for a reason, you just don't have to run it to the intake if you don't want to. OEM connects the hose to the intake to burn off any oil vapors.
.02
LOLOLOL

So here's my question for you. Why the hell would u run a breather filter on something that needs vacuum. If it needs vacuum then a filter wouldnt provide that... just saying. So nice try. Keep it simple and use some common sense. Dude it's funny to look at people who go to school for this stuff and work on this stuff. And then they think they know how everything works... SMDH.
 
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