Its a bad idea to mess with the PCV system for several reasons.
1) The driving force for succesfully keeping the crankcase under a vacuum is very low. Adding a catch can into the path between the crank case and the throttle body increases these losses.
2) The engine management system actually accounts for some oil vapor coming into the intake. This is important because that oil vapor affects the overall octane of the air/fuel in the combustion chamber. (This is true of an EGR (Exhaust Gas Return Valve) when not under boost as well)
3) Failure to maintain a vacuum on the crankcase causes pressure to build on the wrong side of the piston rings. This can affect horsepower and in extreme cases impact the rings ability to seat properly. This in turn increases blowby and makes original problem of too little crankcase vacuum worse.
4) Ironically, for the PCV system to work as designed, it also relies on the restriction of the OEM air filter. Under boost, that restriction insures that the hose at the turbo inlet has vacuum to pull from the crankcase. But, eh, thats the first thing people mess with not realizing that they have affected the lifespan of the rings and increased the risk of leaky gaskets all over the engine.
Its a bad idea to mess with the PCV system for several reasons.
1) The driving force for succesfully keeping the crankcase under a vacuum is very low. Adding a catch can into the path between the crank case and the throttle body increases these losses.
2) The engine management system actually accounts for some oil vapor coming into the intake. This is important because that oil vapor affects the overall octane of the air/fuel in the combustion chamber. (This is true of an EGR (Exhaust Gas Return Valve) when not under boost as well)
3) Failure to maintain a vacuum on the crankcase causes pressure to build on the wrong side of the piston rings. This can affect horsepower and in extreme cases impact the rings ability to seat properly. This in turn increases blowby and makes original problem of too little crankcase vacuum worse.
4) Ironically, for the PCV system to work as designed, it also relies on the restriction of the OEM air filter. Under boost, that restriction insures that the hose at the turbo inlet has vacuum to pull from the crankcase. But, eh, thats the first thing people mess with not realizing that they have affected the lifespan of the rings and increased the risk of leaky gaskets all over the engine.
Please read this information from answers.com.....
The PCV system consists of: 1) The breather tube , and 2) The PCV valve. The breather tube is just an open tube that connects the crankcase to a clean source of fresh air, such as the air cleaner body. The PCV valve connects the crankcase to the intake manifold from a location more-or-less opposite the breather connection. A typical location is the valve cover, although some engines place the valve in locations far from the valve cover.
Counter point to 1. If you install a catch can and notice a change in your idle as noted on your boost guage then yes it might make a difference. BUT, if you make sure there are no leaks then it doesn't make any difference. And what do you mean driving force.... like the vaccuum created by the air passing through the throtle body. Well yes that does change, all the time, as you drive.
Counter point 2. The EMS may take in consideration that there is shit air coming in, but that is why we TUNE our vehicles. Manufactures regularly make stock vehicles run on the side of rich anyway to keep them a little slow, more emission friendly and last longer. Soooooo, if by some chance running a little bit less filthy air into the combustion chamber makes our A/F ratio a little bit more lean, it might actually make the car run better. If any change I'm sure it's not signifigant. Dirty air is still getting in. By using a catch can, sludge that ends up in your intake path will not.
Counter point 3. Not too sure what you mean here. People probibly don't start doing anything with thier cas untill after the break in. In which case your seating of your rings won't be affected. The vaccuum isn't created by the crankcase, it is by the intake air. The only way the pressure would build and hurt anything is if your PCV valve was not working correctly and you let it go for a good period of time
Counter point 4. Your silly. That tube is a fresh air source only, which draws clean air in under normal drive or de-excel and actually vents during boost. It means nothing to have it on the intake or off the intake as long as it's clean air being drawn into the valve cover/crankcase.
I am sure all the people who race normal cars, or performance monsters will tell you all i have said is correct. They have been using breather filters and catch cans for many years now. Shit some rules mandate the use of these things.
Agreed- this actually is better for the engine- you are no longer pressurizing the crankcase under boost when the PCV valve leaks backward (they all do) and oil is not being blown into the intake tract. I cleaned out my cold side intercooler pipe when I installed the PTP CV and I had several oz. of oil in there and none since.
Its a bad idea to mess with the PCV system for several reasons.
1) The driving force for succesfully keeping the crankcase under a vacuum is very low. Adding a catch can into the path between the crank case and the throttle body increases these losses.
2) The engine management system actually accounts for some oil vapor coming into the intake. This is important because that oil vapor affects the overall octane of the air/fuel in the combustion chamber. (This is true of an EGR (Exhaust Gas Return Valve) when not under boost as well)
3) Failure to maintain a vacuum on the crankcase causes pressure to build on the wrong side of the piston rings. This can affect horsepower and in extreme cases impact the rings ability to seat properly. This in turn increases blowby and makes original problem of too little crankcase vacuum worse.
4) Ironically, for the PCV system to work as designed, it also relies on the restriction of the OEM air filter. Under boost, that restriction insures that the hose at the turbo inlet has vacuum to pull from the crankcase. But, eh, thats the first thing people mess with not realizing that they have affected the lifespan of the rings and increased the risk of leaky gaskets all over the engine.
Please read this information from answers.com.....
The PCV system consists of: 1) The breather tube , and 2) The PCV valve. The breather tube is just an open tube that connects the crankcase to a clean source of fresh air, such as the air cleaner body. The PCV valve connects the crankcase to the intake manifold from a location more-or-less opposite the breather connection. A typical location is the valve cover, although some engines place the valve in locations far from the valve cover.
Counter point to 1. If you install a catch can and notice a change in your idle as noted on your boost guage then yes it might make a difference. BUT, if you make sure there are no leaks then it doesn't make any difference. And what do you mean driving force.... like the vaccuum created by the air passing through the throtle body. Well yes that does change, all the time, as you drive.
Counter point 2. The EMS may take in consideration that there is shit air coming in, but that is why we TUNE our vehicles. Manufactures regularly make stock vehicles run on the side of rich anyway to keep them a little slow, more emission friendly and last longer. Soooooo, if by some chance running a little bit less filthy air into the combustion chamber makes our A/F ratio a little bit more lean, it might actually make the car run better. If any change I'm sure it's not signifigant. Dirty air is still getting in. By using a catch can, sludge that ends up in your intake path will not.
Counter point 3. Not too sure what you mean here. People probibly don't start doing anything with thier cas untill after the break in. In which case your seating of your rings won't be affected. The vaccuum isn't created by the crankcase, it is by the intake air. The only way the pressure would build and hurt anything is if your PCV valve was not working correctly and you let it go for a good period of time
Counter point 4. Your silly. That tube is a fresh air source only, which draws clean air in under normal drive or de-excel and actually vents during boost. It means nothing to have it on the intake or off the intake as long as it's clean air being drawn into the valve cover/crankcase.
I am sure all the people who race normal cars, or performance monsters will tell you all i have said is correct. They have been using breather filters and catch cans for many years now. Shit some rules mandate the use of these things.
Thank you for that, I wasnt sure how to respond due to there being so many errors on what he said. He must think that pressurized crank case is good and getting rid of the oil in the intake tract is bad. Not sure about the engine programing and the engineers making adjustments for "oil vapors". I wonder how they would calculate for that in WOT when the PCM goes "dumb". Oh well I will just chalk another one up for the "wow did I just read that" comments and move on. I have 1000's of these check valves out there and have heard nothing but good about them so either everyone is crazy or just one of is a little off there rocker. Still its a very good read and lots of info for everyone to enjoy. Thanks again Adam.
I know it's fully because he gives the perception that you should not mess with the PCV system or the factory intake.
But look at what is in his sig...
Typhoon Short Ram Air Intake w/ heat shield, Crankcase Vent Filter
WTF!!!
I didnt even read what he had in there, what is up with that. I might have pissed him off in another thread some where (I seem to be getting good at that for some reason). Oh well, kind of like calling the kettle black hey.
hey sorry about that post but ive been reading up on this mod and a friend told me he had it done he said it slowed his car down his pt cruiser.
also besides reading on it here ive been reading on other car sites like honda dsm etc and that particular one i got from supraforums when i searched it
and that was all that was said and they werent sure of the mod. but the only way to see for sure is if i try it out and see if it makes my car better.
other cars have check sucky stock check valves? or just ours and thats why we need to do it?
i just wanted to see your responses from that person's comment
hey sorry about that post but ive been reading up on this mod and a friend told me he had it done he said it slowed his car down his pt cruiser.
also besides reading on it here ive been reading on other car sites like honda dsm etc and that particular one i got from supraforums when i searched it
and that was all that was said and they werent sure of the mod. but the only way to see for sure is if i try it out and see if it makes my car better.
other cars have check sucky stock check valves? or just ours and thats why we need to do it?
i just wanted to see your responses from that person's comment
If it slowed his PT down then he should have called me. Was it one of mine? There are lots of generic check valves out there and some really hurt performance due to the poor design of the check valve. Every boosted car should get a check valve for there PCV system. Lots of PCV valves dont like to have possitive pressure pushing on them. I am getting ready to release one for the EVO since I have had a few requests for it and it should be very similar to the SRT4 version.
Breather on the driver's side, and re-route the passenger side PCV exit to the intake somewhere before the turbo.
imo that would allow the PCV to always be under vacume & pulling gasses out of the head even while under boost.
Would look like something like this:
Any thoughts? Possible problems?
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I have no experience with this set-up and have not read anything about it, so i can not give anything but and opion.
For that set-up i believe that be a pretty good boost leak. The purpose of the breather on the valve cover is to expell those bad gasses during boost. Some might have read or experienced the oil on the pad in the stock intake.....that is from the valve cover through the tube durig boost.
Just my opinion though on splitting the line back into the intake.
Yes that will work- you will have a totally passive crankcase ventilation system like in the old days before PCV (positive crankcase ventilation) as a hot rodder from the 60's and 70's I know it works- you just need to make sure the engine can vent pressure in and out so you don't pressurise the bottom end as it will create parasitic HP loss and possibly blow oil out. I have found it best to limit air into the motor and have easy blow out. A catch can and a checkvalve is HIGHLY recommended on any application- street cars these days just throw it back into the intake system. On a turbo or super charger motor you DO NOT want to pressuize the bottom end. Piston ring sealing has nothing to do with the spring pressure of the rings- it is the combustion gas over the piston that seals the rings- therefore anything you can do to decrease pressure in the crankcase/motor is essential. You will therefore increase ring sealing, decrease parasitic motor drag and oil loss. The diagram at the beginning of this thread makes the most sense to me, esp. on a boosted car. The PCV will not hold boost, you will then pressurize the bottom and blow oil/foam out the valve cover into the intake system. You could of course put a catch can there and collect it (NOT!). Makes no sense. A check valve that doesn't allow pressurizing of the crankcase will stop that. You still need to vent the top of the motor- valve cover/ top driver's to allow venting to atmosphere to not pressurize the motor. There are more sophisticated ways to do this with race motors, but this is a viable way to do this- by the way, my catch can is not getting oil and I do not have to add oil like I did before I did this. pm me if you have questions. Dr. MIke
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I didnt even read what he had in there, what is up with that. I might have pissed him off in another thread some where (I seem to be getting good at that for some reason). Oh well, kind of like calling the kettle black hey.
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