What does it consist of? and how will it affect the enviroment? What will happen if we don't use the PCV valve and just use a filter to let the blow-by gas escape into the atmosphere?

I did a search but didn't find the answer
thanks

 

I'm thinking just oil vapors ...maybe some combustion byproducts - but doubtful since the pcv doesnt recycle exhaust air back into the manifold

when you say filter, are you thinking of the filter people put on the valve cover? air goes in that way, not out...

 

Let me explain this a little clearer, the filter I am referring to comes with the moroso catch can and I always have the impressive it is put on top of the catch can, if a PCV valve is not used. So, the blow-by gas instead going back into the manifold, it goes into the atmosphere. Am I mis-interpreted something here? Please educate me.

thanks

 

PCV does in fact recycle some exhaust byproducts into the intake.
And you are wrong about the direction of flow from the valve cover vent.
Blow-by gets into the block and gets recycled back into the system via
the PCV. As far as the environment goes, if you dont run a cat, its the same
thing.

 

the pcv valve definately feeds back into the intake. That is the whole point of getting a catch-can. The catch-can separates the oil vapor from the blowby gas and only sends the gases through the intake. The oil vapor recondenses, and either guts emptied on occasion, or the oil gets fed back into the pan/block. If you vent this gas into the atmosphere, you are defeating the purpose of the pcv system.

As far as the breather hose coming from the valve cover, I have heard different things. Can anyone confirm which direction the air "flows" through the hose? Does blowby gas (which blows by the piston rings) make it all the way back up to the valve cover? I guess it is possible, afterall they are fed oil from the same place, right?

-Floyd

 

So, for off the road purpose, the hole on the intake-manifold (where the PCV route back blow-by gas to) will have to be sealed? If the crankcase pressure is alot, will the amount blow-by gas routed back be too much and affect the efficiency of the engine? I am assuming blow-by gas will not combust as good as intake air.

 

On my motors it only flows out of the engine from the valvecover.
There is quite a bit of pressure and there is no slashcut tube stock so
theres no way it could flow the other way.

citanest: you are right they vapors can cause poor combustion and even detonation
at times depending on conditions, but its illegal to not do it emissions wise.

 

Here is diagram from the Helms manual which should answer these questions.

 

I had my catch can hooked up to the valve cover for weeks and it was still clean. Once I hooked it up to the pcv the hose turned brown with oil after a day.