Breathers and Lean Condition

[icehoc8]

I installed a breather on both the driver and passenger side valve covers. I blocked off the intake tube and the tube that connects to the back of the intake maifold with vacuum caps.
Question is if I DONT run a breather on the oil filler neck, will i suck UNMETERD air and cause a lean condition?
I have no performance mods at all, BONE STOCK 04 Cobra!! Thanks

 

[racebronco2]

you will not run lean cause no un-filtered air is entering the crankcase .... you may end up with oil leaks due to the build-up of gases in the crankcase .... why would you not keep the pvc system hooked-up

 

[FireRed04Vert]

The only thing you're "breathing" is the crankcase...not the combustion process. But I would REALLY reconsider your choice of doing this on a street car. Putting vacuum to the crankcase does a couple of things that are beneficial to your car. First, it can put a slight vacuum on the crankcase which is very good for performance, ring seal, and oil control. (look at a vacupan system some time) 2nd, it will positively vent your crankcase of unwanted byproducts in the crankcase. Every car develops moisture in the crankcase. Once your oil reaches 212 degrees, this moisture turns to vapor and the PCV pulls it from the crankcase. Breathers don't do a very good job of this. Even the very old systems (early 60's) would put a draft tube in the air stream under the car to aid this. If you leave the moisture in the crankcase, among other nasty things like a milkshake, it will turn to an acid and ruin your bearing surfaces and pit your cylinder walls and cam shafts. Not a good feature!! I can't see any benefit to remove the PCV system. If you are from a humid climate, drive your car for a few hundred miles this way then pull your oil cap or breather off. Look underneath it. I will just about guarantee you that you will find evidence of moisture.

 

[cobraracer46]

The only thing you're "breathing" is the crankcase...not the combustion process. But I would REALLY reconsider your choice of doing this on a street car. Putting vacuum to the crankcase does a couple of things that are beneficial to your car. First, it can put a slight vacuum on the crankcase which is very good for performance, ring seal, and oil control. (look at a vacupan system some time) 2nd, it will positively vent your crankcase of unwanted byproducts in the crankcase. Every car develops moisture in the crankcase. Once your oil reaches 212 degrees, this moisture turns to vapor and the PCV pulls it from the crankcase. Breathers don't do a very good job of this. Even the very old systems (early 60's) would put a draft tube in the air stream under the car to aid this. If you leave the moisture in the crankcase, among other nasty things like a milkshake, it will turn to an acid and ruin your bearing surfaces and pit your cylinder walls and cam shafts. Not a good feature!! I can't see any benefit to remove the PCV system. If you are from a humid climate, drive your car for a few hundred miles this way then pull your oil cap or breather off. Look underneath it. I will just about guarantee you that you will find evidence of moisture.

Very well said FireRed04Vert! :beer:

 

[04MystiCobra]

I took my breather off. Seemed like I was getting a tipin lean condition from this but who knows. Been chasing this around for a while now. After the removal it got better. :shrug:

 

[Jimmysidecarr]

Some outstanding explanations have been given as to why you would NOT want to eliminate your PCV functionality.

If you put a breather JUST on the inlet side(used to go to intake tube after MAF)... you could then possibly lean out from un-metered air.

I recommend leaving the PCV hooked up but ..... do the baffle mod... getting the left valve cover off is a BIOTCH but the reduction in oil into the intake is worth it IMHO

LINK---> http://www.modularfords.com/forums/showthread.php?t=31889

PS.. Do you have a Terminator or a 99???

:beer:

 

[FireRed04Vert]

Jimmy...you can also use steel wool instead of the screen. But the problem with that is it's possilbe it could rust since it's steel. But it is very easy to use and does a great job as a baffle.

 

[Jimmysidecarr]

Jimmy...you can also use steel wool instead of the screen. But the problem with that is it's possilbe it could rust since it's steel. But it is very easy to use and does a great job as a baffle.

I would be concerned about stray fibers coming loose...
Where as with the screen... it's much easier to see if you have a loose one that could float free.... and do bad things.

:beer: