BluEVOIX

iTrader: (69)

I was referring "rerouting" as in having the vacuum lines routed back to the intake manifold and intake pipe instead of venting to atmosphere. Similar to how OEM is set up.

But regardless how you route the lines or even vent them. There is nothing you can do to prevent moisture build up under the valve cover when you turn the car off. So it doesnt matter if you have a "good " catch can. Your going to build moisture contamination and mix with the oil.

Running a "good" catch can just helps from having that build up ingest into the intake system (manifold or turbo intake).

cfdfireman1

iTrader: (11)

PCV means "positive crankcase ventilation" as in forced ventilation not passive. H2O is removed along with oil vapors and other contaminants like acids and are then burned along with fuel, or in the case of a good catch-can equipped closed system removed before the intake. Most catch cans are a hoax and just plain don't work because of the way they are constructed with no condensing medium to capture the contaminants that are in a gas or vapor form.

cfdfireman1

iTrader: (11)

coming from? I keep the oil fill cap on when parked outside in the rain.

BluEVOIX

iTrader: (69)

I wasnt telling him what letters P C V mean. But thanks for letting him know.


That depends how you have the pcv system setup. If your setup up to draw in fresh air, then that air will condensate. If your venting to atmosphere, some oxygen might find its way under the valve cover through the vent nipple or pcv and condensate. Even the blow by gasses under the valve cover will condensate as well doesnt have to be fresh oxygen from the atmosphere.

cfdfireman1

iTrader: (11)

Neither air nor oxygen will "condensate" under conditions normally found on earth or in the modern internal combustion engine. Water vapor however will and that's what you want to remove with a good closed system like the stock one with catch-cans installed, yes "catch-cans" one on each side of the valve cover.

BluEVOIX

iTrader: (69)

Interesting....

I was always under the impression that it will condensate. Similar to how your windows build up moisture and fog up.... And we dont have any water in our cars cabin.

cfdfireman1

iTrader: (11)

Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of evaporation. O2 changes state at -170 degrees Celsius, Nitrogen which is 80% of air −196 °C.

BluEVOIX

iTrader: (69)

So whats to stop blow-by gasses to condensate into liquid? Blow-by gasses are mostly carbon monoxide, oxygen, fuel and other possible acids... Doesnt have to be water, but some sort of liquid...

And besides doesnt the air in the atmosphere contain moisture? So when this "air" gets under the valve cover, as it cools it will condensate and form water. Unless I'm wrong?

My03evo

iTrader: (1)

Sounds like you're talking about the kind that people put on that is just a water seperator for an air compressor?

What is a GOOD kind Vs a hoax kind? I see alot of wet oil in my intake from where the pcv ports go into the intake runners so I want to put in a catch can Tee'd into the pcv line or something better. What are some good brands? I saw one that had some kind of mesh inside that assumed helps pull the oil and contaminants out of the vapors going through?

barneyb

The two major components of combustion are carbon dioxide and water. Even a new engine leaks some of these gases past the rings and to the crankcase.

BluEVOIX

iTrader: (69)

Exactly what I was thinking.

Three of the by products of the combustion process are:
* Hydrocarbons (in the form of unburned gasoline)
* Carbon monoxide (formed by the combustion of gasoline)
* Nitrogen oxides (created when the heat in the engine forces nitrogen in the air to combine with oxygen)

And that is exactly what blow-by gasses are .

And another note, catch cans that are routed to ventilate fresh air under the valve cover do just that, ventilate under the valve cover. The blow-by leaks past the piston rings into the crank case area and travel up to the head under the valve cover. Now if your running the PCV vacuum lines as intended by factory, you are not replenishing the blow-by gasses from the crank case with air, just under the valve cover. So in the end you are still contaminating the oil. That is why oil is made to resist contamination for X amount of miles or time.

A simple way to look at it is, open all the doors in your 2 floor house and the windows on the 2nd floor. Then go to your basement and cut the gas line. Now think to yourself, will you be removing all the gas in basement with the 2nd floor being ventilated with fresh air?

Now regardless how you run your catch can lines, there still will be some formulation of condensation under the valve cover because of the types of gasses blowby contain and cooling process when you shut your motor off. And if you have air from the atmosphere enter then that definitely mas moisture in it.

barneyb

Well, yes and no. What you have listed here are three major exhaust pollutants.

The major constituent of combustion gas is nitrogen. Most of the atmosphere is nitrogen, it goes in and comes out of the engine mostly unchanged. The next most common gas is carbon dioxide. Carbon dioxide is one of the results of burning gasoline with oxygen in the air. The third most common gas in the exhaust is water vapor, the other gas that is formed when gasoline is burned.

Theses three exhaust gases make up about 98% of what come out the tail pipe and water is about 13% of that total, the gas of interest here. The gases you mention would be in the remaining 2%.

tkklemann

iTrader: (6)

Mine usually looks somewhat like that...

Its best described as a 40% Mayo, 40% peanut butter, and 20% water.

BluEVOIX

iTrader: (69)

Well then in that case we dont really even need to introduce atmospheric air because we already have water vapor from the combustion by-product in the blow-by gasses.

cfdfireman1

iTrader: (11)

Yes because the vapor density of methane is 0.61 to 0.69.

For every gallon of gasoline you burn you end up with 1.07 gallons of H2O and not all of it goes out the tailpipe especially in a forced induction engine. The water vapor will condense on the coolest surface in the engine which anybody that has opened and old engine that has seen a lot of short trip can tell you is the valve cover. Vent it, move it, and separate it before you burn it again. Want a good catch can that's proven? http://www.saikoumichi.com/