Contour Enthusiasts Group Archives Forums Modifications General Mods Why are free-flow valve cover breathers smog illegal?

Like this one... http://www.zx2racing.com/store/filters.htm#valvebreath ... does it really cause that much more smog?

In a badly worn engine, yes. These emissions are is pretty easily recirculated back into the intake and has been used since at least 1967 or earlier.

Unforunately the Duratec engine recirculates these vapor is such a piss poor way it begs to be changed!
I haven't the foggiest idea what they were thinking when they designed it! They obviously were not thinking in a long term sense (more the a few thousand miles!)

Those breathers defeat the PCV system. PCV stands for positive crankcase ventalation. The PCV system was the first smog device, starting as early as 1961. For normal street use, the closed PCV system is far superior to the old road draft tube that it replaced. The road draft tube didn't provide for any crankcase scavenging until about 25 mph. It also vented all of the blowby into the atmosphere, hence the reason for making the PCV system a smog device.

I've been told by mechanics that built motors before and then after the PCV intro, that a very positive effect on longevity happened after the PCV. Has to with the oil being held under the psiton/etc, NAW forgot, Well the end result better lubication and longevity.
Paul
Besides it will keep the PCM confused, non- metered air also
Jeeze messed this up Big Jim?

Well, the benefits are many...

1. Only let filtered air into crankcase
2. Remove unburnt and burnt gases that dilute the oil
3. Keep those unburnt and burnt gases out of the atmosphere (good for us)
4. Circulates clean air which removes moisture that is boiled off when reaching operating temperature. This reduces acids in the oil (Sulfur from fuel vapors (Burnt and unburnt) mixes with water to form Sulfuric Acid, Water and Carbon monoxide or Dioxide form carbonic acid).

It is only bad when the oil vapor is not removed from the gases and the oil vapor then films out on your intake parts and makes for a dirty, rough running engine. But nobody ever has to clean the intake on a Contour :rolleyes: