1. possible smell of oil fumes
2. layer of oil on engine components over a period of time
3. emission of pollutants into the atmosphere

 

Also, un-metered air (by the MAF) since the fresh air for the PCV system is not going through the MAF. Not sure if it will make the idle different or not - the engine would probably be most sensitive to un-metered air at idle.

 

At the same time that I installed the fixed orifice PCV valve, I also installed an open element (breather type) oil fill cap on the engine.

With the breather cap installed, I have not had any indication of items #1 or #2.

 

Any noticeable change in the idle quality? With an open filtered breather on the oil fill cap, there is un-metered air going to the engine through the PCV system. With the fixed orifice valve, maybe it chokes the flow down to the point were it doesn't make much difference to the engine's idle (?).

Did you then plug the fresh air line going from the intake to the RH valve cover?

I might have to try the oil fill cap breather ... where did you purchase it? You can PM me if you don't want to post that info.

 

There was absolutely no change in idle speed or idle quality.

No changes were made to the factory fresh air line plumbing.

I bought the breather cap from a forum member. It's a K&N chrome top breather, mated to a modified factory oil fill cap base. I'll try to find the original vendor, and send you a PM.

 

Items 1 and 2 typically start showing their ugly heads after the breather becomes saturated. It's similar to a vacuum pump filter in that it most likely needs to be replaced every so often. Still, it will probably not prevent <10-20 micron oil droplets from getting past the filter. Eventually, even with frequent filter changes, an oil residue on the engine will show itself.

 

PM sent to ZeeOSix.

Here's the link to it, if others are also interested.

http://forums.corvetteforum.com/c6-f...need-this.html

 

This could only happen if you retained the PCV valve and put a breather in place of the fresh air line. Even then, it's not a huge difference.

A FOV made my car suck oil into the intake way worse.

I got around oil in the intake by installing a breather and plugging all PCV holes.

I got around burning oil by installing a vacuum pump. It's like a supercharger for the crankcase.

 

You are one of the first guys I've heard of doing that. I'm sure someone else is, but a crankcase evac system is a great way to go. (as long as you're not a tree-huggin hippie lol )

I have seen kits that turn the air pump into an evac pump, would be a neat set-up.

How do you have yours set-up?

 

It would also happen if you just added a breather on the oil filler. Any fresh air that by-passes the MAF will be un-metered. But sounds like the car can take some un-metered air and not really show any effects.

That seems strange, as the purpose of the fixed orifice "valve" was to cut down on intake oil from the PCV system. Did you have any other mods on the car that might have contributed to more oil going into the intake manifold?

 

1) If you just add a breather then you are retaining the pcv fresh air line which is what I said..... If you plug up the pcv system and add a breather then no air is introduced into the intake, just a vent for the crankcase, which IMO is not sufficient, hence the vacuum pump.

2) A 408 with a big cam and high revs...would that make a difference?

 

www.gzmotorsports.com

but beware the kit they sell requires fabrication and some different parts, lol.

good company, great guy to work with though...i let him know the changes I had to make, not sure if they are incorporated into new kits.

 

Of course, it would make a huge difference!

Any stock PCV system would be overwhelmed by the crankcase pressures and vapors produced by that engine.

This discussion was only intended to show the results of installing a fixed orifice PCV valve on stock LS1/LS6 engines.

 

I tried it on my stock engine, too and same results. Worse. ;-)

I was being facetious.

 

I'm finding that very hard to believe.

 

Well, then it never happened.

Do you really think me asking if a 408 "would make a difference" is a serious question???????

I put on headers and nitrous initially. I noticed oil on the plugs/in intake. I researched options, much like you are doing now, back in 2007. I found the FOV and put it on. Car sucked down 2 quarts in 200 miles.....

I put a 408 in, didn't drive it much for a long time, drove it, burned oil and coolant. Had cracked heads. Put on new heads and "burned a lot of oil." I thought it was the heads since I had long forgotten about the FOV. I changed it to a breather (plugged intake entirely) and burned way less but it was not enough to vent the crankcase.

Installed vpump and all is history. It's just my experience, man. If you want to BELIEVE in the FOV, then do it. People believe in all kinds of stuff. On my car, it exacerbated the problem by an order of magnitude.

All I am saying is there is no cure for the horrible design of a PCV system, especially the LS version. The best thing you can do for your engine is unplug it and cap it and find another way entirely of removing crankcase gasses. Like in most cases, what's better for your engine is worse for the environment. No matter what valve you use, the system is still designed to foul up the combustion mixture. I am done with that.