pcv
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From: Crofton, MD
Re: (RotaryBzzzz)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david90 »</TD></TR><TR><TD CLASS="quote">how does vacumn relates of the valves operation? I though camshaft control them?</TD></TR></TABLE> totally different valves. yes the intake and exhaust valves are controlled by the cam, but there are many types of valves.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RotaryBzzzz »</TD></TR><TR><TD CLASS="quote">like a grouse jet</TD></TR></TABLE>
OK. now I'm confused?????
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RotaryBzzzz »</TD></TR><TR><TD CLASS="quote">like a grouse jet</TD></TR></TABLE>
OK. now I'm confused?????
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From: USA
Re: (david90)
it is pretty much a one way valve... it lets pressure out not in... the ball they are talking about is what is used to close the valve if it see's the wrong kind of pressure. the pressure comes in the wrong way and it pushes the ball into place to block flow through the valve. when it sees the right pressure it pushes the ball up and allows flow.
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so when there is pressure in the valve cover (no vacumn), the ball is open because the gas from the engine pushes it? What is the point of the ball opening and closing the valve? why let the gas escape?
when people put breather on the pcv hose (goes to intake), it doesn't create a vacumn in the valve cover, so is it bad? Am I even talking about the same thing? i'm confuse.
when people put breather on the pcv hose (goes to intake), it doesn't create a vacumn in the valve cover, so is it bad? Am I even talking about the same thing? i'm confuse.
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Re: (david90)
Your PCV system has 2 different hoses. The PCV valve is on the hose that goes to the intake manifold. The manifold vacuum sucks air out of the crankcase thru the PCV valve.
The other hose doesn't have any valve in it, and it lets fresh air into the crankcase to make up for what gets sucked out. People put breathers on this other hose.
The ball in the PCV valve does a couple things. It works like a check valve to prevent reverse flow - for example if you had a turbo. But if the manifold vacuum is strong, the valve almost closes so you don't get too much air sucked out. The idea is to have about the same amount of air sucked out through the PCV valve; no matter how strong the vacuum is.
The other hose doesn't have any valve in it, and it lets fresh air into the crankcase to make up for what gets sucked out. People put breathers on this other hose.
The ball in the PCV valve does a couple things. It works like a check valve to prevent reverse flow - for example if you had a turbo. But if the manifold vacuum is strong, the valve almost closes so you don't get too much air sucked out. The idea is to have about the same amount of air sucked out through the PCV valve; no matter how strong the vacuum is.
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Re: (david90)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by david90 »</TD></TR><TR><TD CLASS="quote">assuming there are no problem with the pcv system, under what condition will the valve open? I still don't get the purpose of the valves.</TD></TR></TABLE>
If you remove the valve from your engine, the ball inside is kind of hanging on a spring. You can feel it rattling if you shake it.
If you blow through it very lightly, the ball will stay near the middle. The air goes thru pretty easily. That's like wide-open throttle, when there's not much vacuum in the manifold.
If you blow through it harder, the ball will move and the valve will almost shut so only a little air goes through. That's like when the engine is idling & the vacuum is strong. It's supposed to be designed so that about the same amount of air goes through, even though you're blowing harder.
The purpose of the valve is to suck the same amount of air out of the crankcase, no matter how strong the manifold vacuum is.
If you blow through it in the opposite direction (towards the engine), the ball will move the other way & shut the valve. No more air gets thru. That's useful for turbo engines, so they don't blow air INTO the crankcase. But I really don't know why Honda did that since they don't make factory turbos.
If you remove the valve from your engine, the ball inside is kind of hanging on a spring. You can feel it rattling if you shake it.
If you blow through it very lightly, the ball will stay near the middle. The air goes thru pretty easily. That's like wide-open throttle, when there's not much vacuum in the manifold.
If you blow through it harder, the ball will move and the valve will almost shut so only a little air goes through. That's like when the engine is idling & the vacuum is strong. It's supposed to be designed so that about the same amount of air goes through, even though you're blowing harder.
The purpose of the valve is to suck the same amount of air out of the crankcase, no matter how strong the manifold vacuum is.
If you blow through it in the opposite direction (towards the engine), the ball will move the other way & shut the valve. No more air gets thru. That's useful for turbo engines, so they don't blow air INTO the crankcase. But I really don't know why Honda did that since they don't make factory turbos.
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From: USA
Re: (JimBlake)
the pcv system is not unique to honda's first of all, and the valve is extremely cost effective solution to relieving pressure.
it would be useless if it let the air be pushed or pulled through it without restriction.
it would be useless if it let the air be pushed or pulled through it without restriction.
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