Sorry, a n00b question. I searched but didn't quite get the info I was looking for.

Part 1:

What exactly is happening with the breather and why is it necessary?

From what I found out so far, the breather hose which connects your intake to the valve cover returns possibly unburnt gases (I assume vaporized fuel) back to the intake so that they can reenter the engine and be burnt, thus helping emmissions a lot.

Do the gases go the other way? (from intake to the valve cover)
Why are breather filters replaceable for the breather hose? (if the gas is going OUT of the valve cover, then is the filter there to keep the outside air cleaner and not the inside (reverse of the intake filter))?
Where is the breather valve? Do our Civics have/need one?

Part 2:

So I got a AEM V1 CAI used for cheap (carb legal, and R&D, oh yeah) but the breather hose was just a big fat ugly rubber hose with hose clamps. Usually I see nicer looking thin (silicon?) hoses for the breather. I know hot gases (felt it) are going through the breather hose.

Are there specific requirements for these hoses or can I replace it with practically anything that does the job?

 

Gases typically go from intake to valve cover.

It's hot because it's connected to 2 underhood metal parts, one of which is your valve cover


You can replace it with anything that can take the heat.

 

https://www.honda-acura.net/forums/s...hreadid=106533

 

actually gases from the calve cover go into the intake...
its attached to the intake because it creates a vacuum effect with the tb is open

 

Actually no, unless you are proposing that the intake has more vacuum than the intake manifold. See arrowhead directions on diagrams in other thread.

 

the intake and intake manifold are pretty much connected am i wrong?

 

Correct me if I'm wrong but
- the whole purpose of the breather was to discharge blow-gas in an enviro-friendly way and what better way than to let the engine use it again...

-no it won't go back into the valve cover because there is no vacuum created there but there is vacuum created in your cylinders and that feeds through the TB...and besides that blow-by gas has nowhere else to go so it is a forced out of that one hole...

-and lastly any decent hose should work but use good judgement..

 

actually the vacuum in the intake comes from the cylinders through the intake manifold...so essetially its all the same vacuum...that sometimes varies depending on how far open the TB is:thumbup:

 

i was trying to say that
also especially under boost conditions, the PCV will not stay open and so some people have used exhaust gases which create a vacuum effect to keep it open or attached to catch cans too

 

This is starting to sound like "Which came first, the Chicken or the Egg?"