1994 Honda Accord EX. I replaced my PCV with a simple air filter, which fits nicely in PCV hole in the valve cover. Now I am worried that the crankcase fumes will run backwards through the breather tube into my air intake, instead of out through the filter i put in the valve cover. Is there an after-market part that will inable me to force filtered air into the breather tube to prevent this?
Crank Case Venting
- Thread starter FordPerformance
- Start date
- Status
Why didn't you just get a PCV? Just wondering, I thought that was the whole point of a PCV...to prevent the gasses from going back into the system.
Pcvs are so cheap. What's the filter for?
This reply is for OP.
The "P" in PCV stands for positive. Is your set-up still "positive" ??
The "P" in PCV stands for positive. Is your set-up still "positive" ??
Hi.
Yes I am wondering why you replaced the PCV valve with an air filter. I'm trying to picture that right now.
PCV stands for, like Papa Bear said, Positive Crankcase Ventilation. That means that the crankcase is held at a certain pressure in order for it to function efficiently. Positive pressure within the crankcase means that it is held at a pressure higher than the surrounding pressure. The PCV valve is set to open and regulate crankcase pressure through the PCV valve. It functions mainly to allow excess pressure, oil fumes, and water vapor (from the combustion process) to vacate back into the intake stream where it will be used in the combustion process again.
There is no aftermarket part for the process that you want; I actually have never heard of something like this until now. So I may be wrong. Anyways, I think you should put the PCV valve back.
Yes I am wondering why you replaced the PCV valve with an air filter. I'm trying to picture that right now.
PCV stands for, like Papa Bear said, Positive Crankcase Ventilation. That means that the crankcase is held at a certain pressure in order for it to function efficiently. Positive pressure within the crankcase means that it is held at a pressure higher than the surrounding pressure. The PCV valve is set to open and regulate crankcase pressure through the PCV valve. It functions mainly to allow excess pressure, oil fumes, and water vapor (from the combustion process) to vacate back into the intake stream where it will be used in the combustion process again.
There is no aftermarket part for the process that you want; I actually have never heard of something like this until now. So I may be wrong. Anyways, I think you should put the PCV valve back.
Let's just say that here in NA: unless you have a highly modified, non emissions-compliant (or even non-streel-legal) automobile to begin with, otherwise: it is unwise to casually modify/take away PCV systems on an emissions-controlled vehicle without causing any further drivability issues.
Agree with dtt004 and Papa Bear said.
Q.
Agree with dtt004 and Papa Bear said.
Q.
I was taught that the primary reason for the PCV valve is to stop a backfire from traveling into the crankcase. The PCV works with or without a valve.
Well the filter I speak of is a simple crankcase breather made just for the job. It does a better job of venting the crankcase bacause there is no valve in the way. I did it to keep oil spray from gunking up my intake valves and spark plugs. PCV valves don't filter, they just open and close. Back in the good old days when the government governed instead of designing cars, most vented engines had a setup like mine. Non-vented engines had screw-in dip sticks and dirty oil. Today, all engines are vented, but the fumes from the PCV valve goes back into the air intake. Hense, oily fumes gunking up my intake and plugs.
IMO you are playing a dangerous game in eliminating the PCV system. Sludged engines result when PCV systems are not working properly.(Notice that it is a SYSTEM consisting of several parts) On a '94 accord, you have port injection which can readily be kept clean by using a product like Techron Complete Fuel System Cleaner (or others) on a regular schedule. I use it twice a year on my Mazda and Hyundai. FWIW--Oldtommy
Originally Posted By: 2oldtommy
IMO you are playing a dangerous game in eliminating the PCV system. Sludged engines result when PCV systems are not working properly.(Notice that it is a SYSTEM consisting of several parts) On a '94 accord, you have port injection which can readily be kept clean by using a product like Techron Complete Fuel System Cleaner (or others) on a regular schedule. I use it twice a year on my Mazda and Hyundai. FWIW--Oldtommy
You are probably right, but I am just experimenting here. The car is old and I am ready to replace it anyways. I only use it around town, no highway travel at all. The motor never goes about 3ooo rpm. I'm thinking at those pressures using a breather filter in place of a PCV would actually be beneficial.
IMO you are playing a dangerous game in eliminating the PCV system. Sludged engines result when PCV systems are not working properly.(Notice that it is a SYSTEM consisting of several parts) On a '94 accord, you have port injection which can readily be kept clean by using a product like Techron Complete Fuel System Cleaner (or others) on a regular schedule. I use it twice a year on my Mazda and Hyundai. FWIW--Oldtommy
You are probably right, but I am just experimenting here. The car is old and I am ready to replace it anyways. I only use it around town, no highway travel at all. The motor never goes about 3ooo rpm. I'm thinking at those pressures using a breather filter in place of a PCV would actually be beneficial.
In high school I had a '48 Merc that had so much blowby that it created a blue cloud under the car. I ran that blowby to the oil bath air cleaner and it was burnt and passed out via the tailpipes. At least I didn't have to smell it any more.
Originally Posted By: FordPerformance
Back in the good old days when the government governed instead of designing cars, most vented engines had a setup like mine. Non-vented engines had screw-in dip sticks and dirty oil. Today, all engines are vented, but the fumes from the PCV valve goes back into the air intake. Hense, oily fumes gunking up my intake and plugs.
You know I kinda figured this was yet another "the gub'ment's trying to ruin my engine" threads, but I wanted to give you the benefit of the doubt. Obviously, that was misplaced.
First off, there's a "no politics" requirement for the forum; I realize that many people who have been posting on this forum forever continue to ignore it, so I understand your confusion. Still, you should probably look at all of those rules to which you agreed.
Secondly, your freedom ends when it starts polluting my air...PCV systems, and environmental regulations exist for a reason.
Lastly, engines are designed to incorporate positive pressure from the PCV system as a whole, so applying engine dynamics from an engine from the 60's isn't really helping your engine.
If you maintain your car correctly, your plugs, intake valves, and intake system aren't going to get "gunked up". Yeah, it requires a little more maintenance. Deal with it. Lot of other folks do. What makes you so special?
Back in the good old days when the government governed instead of designing cars, most vented engines had a setup like mine. Non-vented engines had screw-in dip sticks and dirty oil. Today, all engines are vented, but the fumes from the PCV valve goes back into the air intake. Hense, oily fumes gunking up my intake and plugs.
You know I kinda figured this was yet another "the gub'ment's trying to ruin my engine" threads, but I wanted to give you the benefit of the doubt. Obviously, that was misplaced.
First off, there's a "no politics" requirement for the forum; I realize that many people who have been posting on this forum forever continue to ignore it, so I understand your confusion. Still, you should probably look at all of those rules to which you agreed.
Secondly, your freedom ends when it starts polluting my air...PCV systems, and environmental regulations exist for a reason.
Lastly, engines are designed to incorporate positive pressure from the PCV system as a whole, so applying engine dynamics from an engine from the 60's isn't really helping your engine.
If you maintain your car correctly, your plugs, intake valves, and intake system aren't going to get "gunked up". Yeah, it requires a little more maintenance. Deal with it. Lot of other folks do. What makes you so special?
OVERKILL
$100 Site Donor 2021
Originally Posted By: dtt004
Hi.
Yes I am wondering why you replaced the PCV valve with an air filter. I'm trying to picture that right now.
PCV stands for, like Papa Bear said, Positive Crankcase Ventilation. That means that the crankcase is held at a certain pressure in order for it to function efficiently. Positive pressure within the crankcase means that it is held at a pressure higher than the surrounding pressure. The PCV valve is set to open and regulate crankcase pressure through the PCV valve. It functions mainly to allow excess pressure, oil fumes, and water vapor (from the combustion process) to vacate back into the intake stream where it will be used in the combustion process again.
There is no aftermarket part for the process that you want; I actually have never heard of something like this until now. So I may be wrong. Anyways, I think you should put the PCV valve back.
No it isn't.
Positive Crankcase Ventilation vents positive crankcase pressure. The valve is under VACUUM during cruise and idle. The intake is literally sucking air OUT of the crankcase under these conditions.
PCV systems typically have two connectors to the crankcase. On V8's, one is on one valve cover, the other is on the other. Engine vacuum is applied to the PCV valve on the one side, whilst the other side breathes from in front of the throttle body; it has neither pressure or vacuum on it. This is to prevent the crankcase from running under a vacuum condition (which is good for power, but that's another topic). Essentially, the one side is a filtered breather already, as the air it has access to has already passed the air cleaner. And it is also metered air, since it has passed the MAF sensor as well.
So, say you have an engine with little to no blow-by. The engine is applying 19-inches of vacuum to the top of the PCV valve. This is drawing a significant amount of air THROUGH the crankcase (notice I didn't say FROM the crankcase). Fresh air enters from the intake plumbing somewhere in front of the throttle body, is drawn THROUGH the crankcase and up through the PCV valve. Taking with it the nasty crankcase vapours that are the by-products of combustion, oil aeration and break-down, and a host of other lovely things. These end up in your intake stream where they are burned, rather than vented to the atmosphere like in the days of yore.
Of course the issue with this is that in an unhealthy engine, one that creates significant blow-by, you end up with the crankcase stuff not only coming up the PCV side, but up the fresh air side too. There is no "flow through" system at this point, it is just air coming out. And they both vent into the intake. So you end up with build up at your TB from the breather tube, and inside the intake from the PCV tube. This is also how the system functions when you are at WOT or engine conditions where the engine develops little to no vacuum, but of course the massive flow through the throttle body at this point should ensure most of it gets drawn in that way through the vent-tube side.
Hi.
Yes I am wondering why you replaced the PCV valve with an air filter. I'm trying to picture that right now.
PCV stands for, like Papa Bear said, Positive Crankcase Ventilation. That means that the crankcase is held at a certain pressure in order for it to function efficiently. Positive pressure within the crankcase means that it is held at a pressure higher than the surrounding pressure. The PCV valve is set to open and regulate crankcase pressure through the PCV valve. It functions mainly to allow excess pressure, oil fumes, and water vapor (from the combustion process) to vacate back into the intake stream where it will be used in the combustion process again.
There is no aftermarket part for the process that you want; I actually have never heard of something like this until now. So I may be wrong. Anyways, I think you should put the PCV valve back.
No it isn't.
Positive Crankcase Ventilation vents positive crankcase pressure. The valve is under VACUUM during cruise and idle. The intake is literally sucking air OUT of the crankcase under these conditions.
PCV systems typically have two connectors to the crankcase. On V8's, one is on one valve cover, the other is on the other. Engine vacuum is applied to the PCV valve on the one side, whilst the other side breathes from in front of the throttle body; it has neither pressure or vacuum on it. This is to prevent the crankcase from running under a vacuum condition (which is good for power, but that's another topic). Essentially, the one side is a filtered breather already, as the air it has access to has already passed the air cleaner. And it is also metered air, since it has passed the MAF sensor as well.
So, say you have an engine with little to no blow-by. The engine is applying 19-inches of vacuum to the top of the PCV valve. This is drawing a significant amount of air THROUGH the crankcase (notice I didn't say FROM the crankcase). Fresh air enters from the intake plumbing somewhere in front of the throttle body, is drawn THROUGH the crankcase and up through the PCV valve. Taking with it the nasty crankcase vapours that are the by-products of combustion, oil aeration and break-down, and a host of other lovely things. These end up in your intake stream where they are burned, rather than vented to the atmosphere like in the days of yore.
Of course the issue with this is that in an unhealthy engine, one that creates significant blow-by, you end up with the crankcase stuff not only coming up the PCV side, but up the fresh air side too. There is no "flow through" system at this point, it is just air coming out. And they both vent into the intake. So you end up with build up at your TB from the breather tube, and inside the intake from the PCV tube. This is also how the system functions when you are at WOT or engine conditions where the engine develops little to no vacuum, but of course the massive flow through the throttle body at this point should ensure most of it gets drawn in that way through the vent-tube side.
Originally Posted By: OVERK1LL
dtt004 said:
to:Bob Woods. i can remember when cars didnt have pcv s.
in 1967 i had a 1965 chrysler 300L. it had so much blow by the intake valves would cake up so bad it wouldnt hardly run. got tired of taking the heads off, so i put the road draft tube off a 1961 chrysler on it. it did what yours did, a good imitation of a mosquito foggier.
in 1967 i had a 1965 chrysler 300L. it had so much blow by the intake valves would cake up so bad it wouldnt hardly run. got tired of taking the heads off, so i put the road draft tube off a 1961 chrysler on it. it did what yours did, a good imitation of a mosquito foggier.
to: Bob Woods. My first girlfriend in high school had a '48 Ford.
The back seat in that thing was made for makin' out ....
thank's for the flashback !
The back seat in that thing was made for makin' out ....
thank's for the flashback !
Mine was a four door sedan, so yes, it had plenty of room.
- Status
