the one by the battery (that fills up much quicker than the other) looks like it would be a huge pain to drain...

 

The one by the battery is for the breather of the valve cover, which has been reported to barely collect residue/oil. The one on the firewall is for the PCV valve, which has seen a decent amount of oil collection.

The one by the battery is still easy to drain though. All I need to do is loosen 2 bolts and take it out to drain

 

cool cool. and thanks for the pics.

 

No problem. I highly recommend the DC-3. It is by far the best bang (if not the best cath can period) for the buck, correctly designed catch can out there.

 

i would agree. now all i need to do is install mine...

 

Well, I think the blow-by when cruising will still get thru to the intake manifold - it has to. To me, they are selling a "high performance" PCV which doesnt leak under boost and it will keep blow-by in the cylinder head at full boost etc...

Now, I would like to see if they pull vaccum like he mentions. That sounds impressive. What I don't understand is why he doesnt just replace the PCV valve with this one. Maybe, I should read it once more...

 

OK guys.

This is advanced tech, not "I love my new catch can"

I will be asking the mods for advanced tech to split the thread putting the "I love my new catch can" crap in EVO General.

Keith

 

I agree with the need for one catch can. However, does the PCV valve actually leak, has anyone tested the value to see how much pressure it will old. If it does start to leak, what about using two PCV valves. If the first one leaks a little bit the second one should still block the air. However, they should both open up to allow flow in the proper direction. This should eliminate the need for a second catch can.

 

A normally functioning PCV valve is supposed to allow oil vapors through to the manifold.
The catch can is meant to filter out oils and stuff which lower the octane levels,etc.

 

I understand how PCV values function. I'm not suggesting the you make the valve so that it does not allow air through. However, I am saying that the reason for having two catch cans is because under boost when the manifold has positive pressure, people claim that the PCV valve leaks and allows air to flow out of the crankcase and into the intake tract. If you were able to make it so that the PCV value did not leak, you would only need one catch
can

 

ok, but each valve requires pressure to close. If the first one closes, then the second one does not have enough pressure to close, essentially it isn't doing anything.
It would be great if PCV valves did not leak.
I think somebody just posted a link to one of those. They are expensive, and you still need a catch can to filter out blow-by during idles/slow rpm.
There are different ways to achieve the same thing.
I don't like to alter the original PCV system's function.
so, 2 catch cans do the job, and the PCV system stays the same.

 

If the first one was leaking...it would provide enough pressure to close the second one without being so much pressure as to make the second one leak. If the first one does not leak at all then the second one will never close, but that is fine since that purpose of the second one is to stop the leak if it was there.

Any links to this non-leaking PCV valve?

 

Even with zero leakage of the PCV valve under boost you still end up with positive pressure in the crank case under heavy load due to blow by from the combustion chamber past the rings into the crank case. This is the main reason you need a dual catch can setup. The PCV leaking does not cause the problem but it does make it worse.

Keith

 

It is post #282 in this thread

 

You may want to check that post number now that the thread is split More than half of the stuff in this thread was related to selling your cans and is now in it's own thread here:

https://www.evolutionm.net/forums/sh...d.php?t=209109

Keith