PCV valves are very different. Not just in size but in the amount of vacume it takes to open them up. The theory of the PCV valve is to create a vacume in the crankcase, valvecovers, lifter vally, so oil will not try to force it's way out of the gaskets and past seals and rings. the vacume is created from intake manifold vacume being used through the PCV valve. When the throttle is opened manifold vacume drops and the PCV valve closes to keep the vacume in the crankcase, to keep the oil in.
Readers Digest Condensed version.......
PCV won't work if:
Too much cam...not enough manifold vacume
Too much blow by past the rings
PCV valves are rated by vacume so you may need a different pressure PCV valve.
Some are spring loaded and some work on gravity..make sure they are in the position intended.
They won't suck at WOT (wide open throttle) Not supposed to.
The hookup to the manifold should be into the main plenum of the manifold because there is a most constant vacume there. Not a manifold runner. (too many pulsations) That's good for Vacume brake booster.
The vent should be in the opposite side valve cover to vent the WHOLE engine.and the higher the filter the better. That's why most are vented from the aircleaner. Clean air goes in that tube and out the PCV and is burned up in the combustion chamber with the air-fuel mix.
Now that I have truly mixxed
you up, you should know everything there is to know about PCV valves.
Fred
Positive Crankcase Ventelation
Threaded Mode
