Originally Posted by
Sleepy445FE
Same here. PCV on the passenger side and breather on the drivers side.
You need the PCV hooked up or you'll likely run rich without the extra bit of air it provides. A breather on the opposite valve cover is usually used when you go to a open style air cleaner. In stock form, the hose connects under the air cleaner behind the filter to give it clean filtered air. With an open air cleaner there is often no provision for this so you give it it's own little air filter.
So you can either keep using the one breather and go to an open air cleaner (adds a few hp), or just ditch the breathers and hook it up as normal.
@1FastGambler it needs to be a circulating system. Clean air goes in one side and gets pulled out the other.
Very interesting, but how do you determine which side does what? Drivers side is positive pressure, or is it passenger side? Just something I thought of haha.
And if I wanted to use an open air cleaner, I could use BOTH breathers, correct?
I'm not really a big fan of all the stuff that's attached to the air cleaner/carb because it makes it difficult to take the carb of and re-assemble (sort-to-say) when I go to start the vehicle back up.
And why would an open air cleaner allow me to run BOTH breathers? I'm not sure I understand the difference and how it creates BOTH vacuums on the valve covers instead of one vacuum and one positive pressure (crankcase gasses that need to be pushed out).
Originally Posted by
HIO Silver
This is where the terms "open emissions system" and "closed emissions system" come from.
Open systems have a breather cap on one valve cover and the other has a PCV (Positive Crankcase Ventilation) valve. It's considered positive because crankcase air expands when heated creating positive pressure. Conversely, a negative pressure creates a vacuum.
The PCV valve is a check valve (take it out should rattle when it is shaken) that allows crankcase gases to be vacuumed out and mixed with the air-fuel mixture and burned during combustion. The breather cap is the "intake" side of the crankcase.
On a closed system, the breather cap inhales on the clean side (filtered) of the air cleaner.
If the rig is subject to emissions testing or visuals, then ya gotta replicate what it came with. Otherwise, feel free to do what ya want but as others have posted its' a good idea to evacuate the stale air and airborne particulates in the crankcase to keep the oil that much cleaner.
Oh, a clogged PCV will cause your engine to run rough because it is not receiving the volume of air vacuumed out of the crankcase... therefore, it will run rich.
Great info on the PCV valve there HIO.
Can you help out to answer the questions I gave sleepy?
I'd be interested in going with an open air cleaner (and both breathers as sleepy was suggesting), but if it's going to clog the S**T out of my engine and not allow it to get rid of those harmful gasses, then I'll stick with one breather and one PCV.
One last thing... If I went with a 1 PCV valve & 1 breather set-up, the PCV valve goes on which side (how do you determine)? AND, where does the PCV valve get hooked up to? Air cleaner or directly to the carb?
There are no emissions BS to deal with here in Saskatchewan, and even if there were, they're so loose about it that it wouldn't matter because vehicles are never checked over before they're registered and licensed.