Anyone make a valve cover breather for PS.``

[ronbuick]

I would like to replace the oil fill cap with a breather for our cars, anyone
know of one out there, checked K&N, but could not find any info, thanks.

Ron

[Crazy Paul]

You might like to read this thread from start to finish.

http://www.forum.grrrr8.net/showthread.php?t=1694&highlight=breather

[Darkside]

Or.............

Originally Posted by HSV-GTS-300
Because:

The MAF measures the air that passes through it to be consumed by the engine and has input into the fuel to be injected. The small fresh filtered air supply tube (after the MAF) that connects to the passenger side valve cover contains "metered air". This air goes into the valve cover, flushes out the harmful gasses which end up going into the side of the intake manifold to be consumed by the engine.

Putting a breather on the valve cover negates all that. A small amount of metered air is now constantly lost to atmosphere. This not only gives you an oily smell inside your car, it's most likely illegal, it also throws your tuning off.

Where once you had a crankcase closed to atmosphere and under a slight vacuum, you now have a crankcase at atmospheric pressure inside. The crankcase seals were not designed for this. This can lead to oil leakage from your rear main seal in particular.

THE PCV system is designed so that the harmful, often acidic and possibly toxic gasses which are by products of combustion are flushed out of the crankcase by a flow of fresh air. These by-products are consumed by the engine. If the valve cover breather does not fully evacuate these gasses properly you will have compounds condensing in the crankcase and possibly eating away at parts. Oil life can also suffer from condensed moisture and acidic residue.

Also in some conditions instead of venting, your breather may actually be sucking. Any dirt or moisture will be trying to get into your engine thru the gauze of the breather.

[Crazy Paul]

Something else I just thought about is condensation. Whenever I dump my catch can the majority of the contents appear to be water.

It kind of makes sense that whenever you turn off a hot engine and allow it to cool, the hot air and fumes within the crankcase will condense. Water and condensed gunk will drop into the oil and onto metallic surfaces.

If you have a functional PCV system then the constant flow of fresh filtered air pushes out the heavier fumes from within the crankcase. It also acts to dilute the fumes.

A breather located on top of the valve cover would I think only vent off the lighter gases residing at the top of the engine. There is no airflow thru the engine to push the heavier gases out from below in the crankcase.

Where the PCV system constantly freshens the air in the crankcase, I could see it being possible that a valve cover breather system could compound the dense gasses "trapped" in the crankcase.

[Darkside]

Off topic Paul, but have you ever posted pictures of YOUR car?

[Crazy Paul]

Not sure.
It's a 2001 VX GTS with an LS2 transplant.

http://f.imagehost.org/0278/WPb030014.jpg

[bigwillys58]

Not sure.
It's a 2001 VX GTS with an LS2 transplant.

http://f.imagehost.org/0278/WPb030014.jpg
woa! that really is a 4 door gto! thats a sweet lookin ride man!!!

[MANOFSTEEL69]

Nice Paul! The background looks amazing as well!

[99-LS1-SS]

Dang Paul! That is a nice looking car!

[ronbuick]

What do you boosted guys do to relieve pressure that could be pushed into the crankcase under boost, gotta go somewhere, why could you not put in a VC breather,
and then a small type K&N on the tube and block or plug the hole going into intake pipe.
thanks

Ron

[wreckwriter]

Check valve on PCV line to stop boost from entering.

[ronbuick]

The Turbo Regal's use a specific PCV where you do not have to install a check valve, it is application specific, but on the TTA's they have a check valve on the power brake vacuum line, where the Buick does not need it because of a different master cyl. set-up, but the Buick guys all put in breathers in the valve covers, what makes this set-up any different as far as breathers go
whether the vehicle is N/A or FI. Now I'm not worried about emissions if that is the only reason.
Ron

[Darkside]

Very nice Paul, thats the first I've seen it.

[neuralfraud]

Not to resurrect ancient threads for no good reason, but the discussion is fairly open ended at this point, and I think the information may not be entirely accurate - of course I may in fact be wrong :)

First, the problem is the theory that the metered air is being *pushed* into the engine via the pcv tube from the intake in order to circulate the gasses through the intake to be consumed - at least, that is how i interpreted following section:


Because:

The MAF measures the air that passes through it to be consumed by the engine and has input into the fuel to be injected. The small fresh filtered air supply tube (after the MAF) that connects to the passenger side valve cover contains "metered air". This air goes into the valve cover, flushes out the harmful gasses which end up going into the side of the intake manifold to be consumed by the engine.



The problem with that is based on my understanding of engines and PCV, and according that understanding, the theory is wrong. The PCV valve is0 normally closed and only opens when positive pressure builds from within the crankcase. This pressure opens the valve, allowing pressurized crankcase gases to escape. The gases flow through the valve and through a tube usually connected to the intake. The intake in essence is helping this by creating vacuum which pulls the valve open and the result is more efficient ventilation of crankcase gasses. This is great for emissions because your engine burns waste gases, the problem is, oil isn't exactly friendly in the combustion chamber, and that is the reason why intakes get soiled with oil in the first place-the intake is a vacuum chamber and it is sucking oily gases into the intake stream.

Catch cans - assuming they work perfectly, isolate the oil droplets, but you still have the gases to deal with which may (and probably do) have a significant octane-reducing effect, which in turn results in increased knock potential and can cause detonation.

Breathers provide constant ventilation to atmosphere and as long as implemented properly, for example I reference this bit from an article in GM High Performance Magazine:

LS1 Engine Build - Connecting breather/ventilation (http://www.gmhightechperformance.com/tech/0611_ghtp_ls1_engine_build/photo_60.html)

This is probably similar to the L76. Note the valve-cover to valve-cover bridge, which is necessary if you're only going to have one breather such as on an LSx motor.

Final thoughts? Perhaps this topic can be closed definitively?

Regards

[Crazy Paul]

- of course I may in fact be wrong :)
Yes you may.



First, the problem is the theory that the metered air is being *pushed* into the engine via the pcv tube from the intake in order to circulate the gasses through the intake to be consumed -
Foul air can travel in both directions thru the PCV fresh air tube depending on pressure differentials between crankcase pressure and "pressure/vacuum" in front of the throttle blade. An aftermarket non-return or check valve added to the system can address this.



The problem with that is based on my understanding of engines and PCV, and according that understanding, the theory is wrong. The PCV valve is0 normally closed and only opens when positive pressure builds from within the crankcase. This pressure opens the valve, allowing pressurized crankcase gases to escape. The gases flow through the valve and through a tube usually connected to the intake. The intake in essence is helping this by creating vacuum which pulls the valve open and the result is more efficient ventilation of crankcase gasses.
There is no PCV "VALVE" fitted by GM to the engines we are talking about.
LS1 engines up until about 2004 had an external PCV Valve....which opened and closed based on pressure differential. It was a simple check valve......I think it was a floating ball in a chamber. It certainly rattled when shaken.
After about 2004 GM went away from the valve to instead having a metering device......it's simply about a 3mm diameter orifice. No moving parts, nothing to open or close.
Orifice is in the valley plate on very late LS1, all LS2,LS3,LS6,LS7,L98 & in the rear left valve cover on L76.




Breathers provide constant ventilation to atmosphere and as long as implemented properly, for example I reference this bit from an article in GM High Performance Magazine:
Regards
Breathers are great if you don't care what comes out or goes into your crankcase via a $2 filter. (Ohhh but it's shiny, it must be good).

[G8V8]

Yummm. Shiny....
The last time paul was wrong about G8 or VE issues was....like....let's see.....umm.....i think, like.......maybe never.

[Crazy Paul]

Yummm. Shiny....
The last time paul was wrong about G8 or VE issues was....like....let's see.....umm.....i think, like.......maybe never.

Nope, I get things wrong all the time. I don't own a VE and have never seen a genuine left hand drive G8 so that's my excuse.

[Napalm]

Its funny cause way back before the 1970s that foul air was allowed to just push out the back of the engine down a small rubber tube. Which is why the backs of a lot of engines had oil film and grease.

The pressure would build up during higher RPM's and positive crankcase venting would occur out the back. This would still work today, quite well actually. but since emission regulations require you to could the hydrocarbons and particulates that exit the vehicle in its entirety, the PCV system was created. And like Paul mentioned the lack of the PCV valve is possibly the greatest thing since sliced bread. The metered MAF air I'm not thrilled about, but its OK. Theory goes that air ends up in the combustion chamber anyway, just a few firings latter.