breather bypass

[Jorgie Hidalgo]

sooo.....do i put a little filter on my intake hole or no?what about the one on the left of the engine block do i top that one?

 

[Michael Cacioppo]

Tom, I don't have my Trac with me so I can't verify first hand if the passenger side valve cover is taking in or sending out gases, so I can not say with certainty one way or the other. Tom my question to you is what causes the vacuum in the passenger's side valve cover to "suck in" the air?



Tom, we are talking about the connection to the passenger's side valve cover, aren't we?

 

[Tom Schindler]

Tom, we are talking about the connection to the passenger's side valve cover, aren't we?

All vacuum is produced downstream of the throttle body. Anything upstream of the throttle body is ambient pressure. The air goes from the intake duct between the MAF sensor and the Throttle Body into the engine. It travels through the engine to the drivers side valve cover. From there, the air goes through the PCV valve (note the name, "Positive Crankcase Ventilation") through a line to the intake manifold. If you are getting crap in your intake pipe, it is because the PCV valve is bad or dirty. The valve will open during vacuum and close without vacuum present.



That is the way the PCV system works.





Tom

 

[Gavin Allan]

All vacuum is produced downstream of the throttle body. Anything upstream of the throttle body is ambient pressure. The air goes from the intake duct between the MAF sensor and the Throttle Body into the engine. It travels through the engine to the drivers side valve cover. From there, the air goes through the PCV valve (note the name, "Positive Crankcase Ventilation") through a line to the intake manifold. If you are getting crap in your intake pipe, it is because the PCV valve is bad or dirty. The valve will open during vacuum and close without vacuum present.



That is the way the PCV system works.





Tom

Amen. I don't know how to explain it any better than this.

 

[Tom Schindler]

To add to that, the valve will close with either a spring or gravity, depending on its design and location relative to the engine.





Tom

 

[Michael Cacioppo]

Gavin and Tom. To put a positive conclusion on this issue I tested the passenger's side of the valve cover at a fast idle....ya know what? You are both...........correct. I stand corrected. There is a reasonable vacuum in that cover.



Again...I stand corrected.



I agree on your explaination of the PVC system. As stated it is a positive ventillation meaning in my opinion that the deiver's side cover is positive in pressure. I have no problem with that. I need to figure out why the same pressure isn't present on the passenger's side.



In older cars with PCVs one cover was not at all vented. As pressure increased in the other cover it was vented via the pvc back into the air cleaner or intake manifold. The practice on HP motors was to vent both sides. Possibly the plumbing on new engines is different. Either way, I repeat "at an idle (at least) the air goes from the outside into the passanger's valve cover."