guys not using the PCV
- Thread starter SIXBANGR
- Start date
I had smoking issue with PCV connected normally and tried replacing with everything that was available but no luck. I took the PCV out and installed a ribbed brass fitting and ran a hose to small K&N breather like the size of the passenger side valve cover breather. I zip tied it to the Trans dip stick tube. Going on three years now, no smoking and no other issues. I do change my oil often and it's pretty clean even though it's old tired motor that I beat the crap out of every time I take her out.
HTH
Prasad
HTH
Prasad
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
You can trust me about the combustion. I remember raising an eyebrow about it myself back in school but it's true for both gasoline and diesel.The catch can generates moisture but the motor case doesn't?
Combustion itself does not have moisture in it. It's the cold metal that condenses when warm gasses are trapped inside. Little catch can does not even compare to the motor case.
Breathers do not pull the moisture out. The gasses swirl around in the case with only a small amount escaping out the breathers.
RL
It's part of the chemistry. Google "gasoline combustion equation" and you'll see what I mean. C8H18 + O2 -> CO2 + H2O
The engine is (or should be) hot enough to prevent condensation from forming inside the crankcase. If it's not, then it needs to get warmed up so it can vaporize the water and vent it out.
Routing the hot blowby gasses through a cold canister or a cold hose is where a problem occurs. When the gasses hit that cold metal, the gasses cool and the water condenses out.
You can trust me when it comes to breathers...
Patent Pending: This heated breather tube design was one of my babies. It has been in production on the International MaxxForce 13L and 11L engines for several years now.
http://www.faqs.org/patents/app/20100186686
- Joined
- Feb 18, 2006
So when egt's reach 1200-1300 degrees your saying there is moisture in there?
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
Yes, very hot water (steam). Think of a car starting and driving away on a cold morning. The exhaust pipes are cold, so you can readily see the condensed water vapor or even water drops coming out of the tailpipe. That water is primarily the product of combustion (a portion of it comes from the ambient too). When the pipes get hot, it's still there just not as easy to see. Or think of a coal fired power plant. After they scrub off all the soot from burning the coal, all that's left is massive quantites of steam. That's what we see coming from the stacks.
- Joined
- Feb 18, 2006
I would think you would be on the the other end of this pcv thing. No phun intended but my argument is totally based on cold weather starts and the time before the motor has reached full temp. Combustion making moisture would further support the use of one.
We know there is moisture in the motor on cold starts. Specially when we're talking below freezing yet we are arguing about a simple device that can evacuate that moisture and other contaminance. It also keeps the nasty vapors out of the cockpit with absolutely no ill effect to performance.
I think you will soon reconsider. If not I tried.
RL
Exhaust fumes or breather fumes?
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
It seems we both agree that getting the engine hot each time it is run is important in order to vaporize the liquid water which has condensed in the crankcase. We don't have to worry about that.I would think you would be on the the other end of this pcv thing. No phun intended but my argument is totally based on cold weather starts and the time before the motor has reached full temp. Combustion making moisture would further support the use of one.
We know there is moisture in the motor on cold starts. Specially when we're talking below freezing yet we are arguing about a simple device that can evacuate that moisture and other contaminance. It also keeps the nasty vapors out of the cockpit with absolutely no ill effect to performance.
I think you will soon reconsider. If not I tried.
RL
But the catch can is just a bucket of oil and water that can collect and potentially be sucked back into the intake manifold. Or worse yet it can ice up and freeze solid in cold weather and block off the crankcase ventillation.
An open breather which vents the water vapor directly to atmosphere is a better solution since there's no opportunity for water to collect and cause problems. Once the water is out of the crankcase and it's gone then we're all done, don't have to worry about it anymore. The only real drawback to an open vent breather is the odor. I've found that Valvoline has a "not to bad bouqet" and a crisp finish...
I imagine the next concern one might have is about the quantity of oil caught in the can. That is a completely separate issue and doesn't have anything to do water and other contaminates. It's an oil carry over issue. Finding a 1/4 quart of oil in the catch can every couple hundred miles or so means that there is a substantial oil carry over problem.
The oil carry-over issue can be eliminated by reducing the velocity of the blowby gas where it's exiting the crankcase. (bigger hose, multiple flow paths, use of a PCV valve, etc)
I do not mean to irritate you Rick, that is not my intention at all. Please don't take my post that way. I spent about 5 or 6 years engineering breather systems on big diesels and solving lots of problems just like these. I learned a lot and I'm just passing it on.
jasjamz
THS Racer
- Joined
- Sep 30, 2004
Breather... I don't even use those check valves that go in between. I may get a a film of oil after a few weeks or a day a the track. Nothing to cause me to think there is a problem though. This year will use the foam breathers covers to end that film issue.
- Joined
- Feb 18, 2006
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
You are correct, the PCV cannot vent the crankcase when the engine is loaded. The engine needs to vent to an open breather for that, which is the way most cars are set up. Most guys run a PCV to pull the gases into the intake manifold during vacuum, and use an open breather on the valve covers to handle venting during boost.
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
Ditto my good manAll in good debate Steve. I appreciate your experience and your patients.
RL
- Joined
- Feb 18, 2006
So I go to empty my catch can over the weekend and you're not going to believe what I found. Full of water and white creame. I wondered where the coolant was going. Luckily I don't run antifreeze in my car.
So back to the pcv and it's importance. When a problem like this shows up the pcv vacuums out the moisture that would otherwise stay inside and make a big mess. The catch can did a great job at capturing the contaminants. You would not believe it. It was full of clear water. I knew right away what was up. I cleaned the catch and went for a short ride to confirm. When I came back the catch had about 1" of clear water and more creame.
So I take the intake off and make up some block of plates. Pressurize the the system and low and behold, the passenger hg is seeping. Not real bad so I decide to pop the intake back on and run some sealing tabs. So far so good. Took a long ride last night. No more water in the catch. Just a little creamy. The last of the moisture that getting vacuumed out.
If no pcv was being used there would no doubt be a big mess inside the motor. It does a very important job and does it well.
I changed the oil it showed no signs of water. I was surprised given the amount of water in the catch.
RL
I wondered where the coolant was going. Luckily I don't run antifreeze in my car. So back to the pcv and it's importance. When a problem like this shows up the pcv vacuums out the moisture that would otherwise stay inside and make a big mess. The catch can did a great job at capturing the contaminants. You would not believe it. It was full of clear water. I knew right away what was up. I cleaned the catch and went for a short ride to confirm. When I came back the catch had about 1" of clear water and more creame.
So I take the intake off and make up some block of plates. Pressurize the the system and low and behold, the passenger hg is seeping. Not real bad so I decide to pop the intake back on and run some sealing tabs. So far so good. Took a long ride last night. No more water in the catch. Just a little creamy. The last of the moisture that getting vacuumed out.
If no pcv was being used there would no doubt be a big mess inside the motor. It does a very important job and does it well.
I changed the oil it showed no signs of water. I was surprised given the amount of water in the catch.
RL
TURBOPOWERED68
David
- Joined
- Jan 31, 2006
So I go to empty my catch can over the weekend and you're not going to believe what I found. Full of water and white creame.
So back to the pcv and it's importance. When a problem like this shows up the pcv vacuums out the moisture that would otherwise stay inside and make a big mess. The catch can did a great job at capturing the contaminants. You would not believe it. It was full of clear water. I knew right away what was up. I cleaned the catch and went for a short ride to confirm. When I came back the catch had about 1" of clear water and more creame.
So I take the intake off and make up some block of plates. Pressurize the the system and low and behold, the passenger hg is seeping. Not real bad so I decide to pop the intake back on and run some sealing tabs. So far so good. Took a long ride last night. No more water in the catch. Just a little creamy. The last of the moisture that getting vacuumed out.
If no pcv was being used there would no doubt be a big mess inside the motor. It does a very important job and does it well.
I changed the oil it showed no signs of water. I was surprised given the amount of water in the catch.
RL
posts like this make me want to RUN and install a Catch can set up.
BTW i do use a PVC valve i tried the car with out one and the cruise and idle fumes were TERRIBLE.
I have a question for you guys who run a catch-can setup - does it keep oil from getting sucked into the throttle body? Seems to me that it SHOULD keep that from happening, and that this would be one of the greater benefits of running a catch can (if you are still running PCV). Keeping oil out of the intake would be a major plus but if the catch-can doesn't help with it, then is it really worth it.
If you limit the amount of vacuum drawn by the pcv (by the adding an additional check valve inline) there shouldnt be any additional oil consumption.
But it seems to me that adding a check valve would change the way that the PCV is designed to operate. I mean, the PCV is a check valve. It allows vacuum to suck out the blow-by gases so that they get directed into the TB and burned. Under boost, it keeps the boost from entering the intake.
My main concern is keeping the LIQUID oil out of the intake. Does installing the catch-can keep liquid oil out of the throttle body? If so, I would plan to install, but if it doesn't it seems that it's a waste of money. My concern is not the water vapor, but is the fact that the liquid oil would enter the TB and combustion chamber.
