Quote Originally Posted by shine View Post
keep in mind the pcv is just a smog device. i run the large moon breather to vent. if you run the pcv and a solid cap on the other side it will blow oil out every seal in the motor.
When the PCV was originally designed it was a sealed system smog devise and quickly resulted in seal and other motor problems. The addition of a breather to reduce negative pressures solved the problems and the benefits were soon learned and practiced on even race motors. Improvements to the system continued including valve cover splash baffles exc.. A properly operating PCV system will also aid in keeping the internal engine parts cleaner by reducing some of the harmful gases that will cause corrosion.
IMHO, the benefits of a good operating PCV system far out ways any disadvantages and I have PCV on every motor I have.