Engine breather - probably not what you think..

Wagner ME PCV valves work very well and have the advantage of being adjustable based on idle vacuum.
In this post, Panteradoug mentions a 25 hp gain when the crankcase is under slight vacuum with a good PCV.

https://pantera.infopop.cc/top...77#14131809569880077

The M.E.Wagner is a useful tool to those who are also wrestling with camshafts that produce low idle vacuum. Anything below 10 or 11 inches is not going to help with the piston ring sealing. It will be detrimental to it.

That is what you NEED minimally to seal the compression rings.

With low idle vacuum, there the cylinders are going to show evidence of "cylinder washing" and  that alone will add to spark plug fouling.

You shouldn't go below the 10" level. The higher, the better.

Doug, are you running PCV on Webers or 8 stack EFI?

Roland, I have run PCV on all but one of my six Panteras.  I like PCV for the reasons that you detailed.  Another benefit is that the engine is not as smelly when running with PCV.

I am setting up my 8 stack EFI to use an oil separator/breather/catch-can as seen on GT40's.  You can see the beginning of the plumbing for it below with AN hose fittings in the valve cover breather ports.

@stevebuchanan posted:

Doug, are you running PCV on Webers or 8 stack EFI?

Yes, a M.E.Wagner and I am using an oil sererator/catch can as well.

I only have 12" at idle so I found that I had to regulate the "vacuum leak" by installing a plug in the passenger side breather and limiting the size of the hole that the engine sucks air in through. Otherwise I lost 3-4 inches through the stock breather hole in the oil filler cap.

I had built a vacuum manifold out of an old Mr.Gasket fuel manifold and mounted it horizontally just above the top of the block at the bellhouse connection.

I had already plumbed the intake manifold with -3 tubing and t-fittings in series.

That runs to the vacuum manifold and is what supplies the vacuum to my system.

The PCV valve and catch can are plumbed to the other side of the vacuum manifold.

The vacuum manifold also provides other vacuum connections like for the vacuum gauge.

You can't see much of it because it is tucked against the header heat shield.

I also machined the driver side valve cover to take the PCV valve there in the back of the valve cover v, the original location in the front and plugged the original front port.

This way it is all more accessible to the back of the engine.

Very trick… as @panteradoug said if you are running a very hot cam - vacuum is at a premium…

Not having a PCV is bad for the engine and the performance..

@stevebuchanan there are way to many people out there that don’t know how it works and all the advantages a PCV has..

including no oil fumes..

@LeMans850i posted:

@stevebuchanan there are way to many people out there that don’t know how it works and all the advantages a PCV has..

including no oil fumes..

Others have tried the drag racing solution of getting vacuum by connecting to the header collectors.

There are two issues with that. 1) it only provides about 7" of vacuum and only at WOT 2) it sucks oil out of the valve covers into the exhausts

By the same token, the engine can't use more then about 10" of vacuum in the PCV system safely. At 12", the oil control rings can collapse or at least loose their effect.

You can see oil on the plugs in a stock engine run hard. So the balance needs to be just right. More vacuum isn't necessarily better.

Stock cams can give you over 17-18 inches but the stock PCV system bleeds off 4-5 inches into the air cleaner, so that's the way the "factory" balances that out into a "safe range".

Incidentally, the Chevy L-88 PCV is special to that engine because that engine only has 10-11 inches at idle as built.

The issue is that the current aftermarket valves are very, very , not good and you would need to find an original GM part that still works.

The ME Wagner is a much better solution.

@panteradoug I am building a blow through catch can - from the PCV valve to the catch can from there to the intake..

the ME Wagner makes my life easier for sure..

@LeMans850i posted:

@panteradoug I am building a blow through catch can - from the PCV valve to the catch can from there to the intake..

the ME Wagner makes my life easier for sure..

You just need to locate a catch can somewhere in line with the PCV. Some use a screen in the can to work as a scrapper but I find that unnecessary for my set up.

It accumulates water vaper and very little oil if any.

Whatever you select as a catch can, pressure test the thing to make sure it seals tightly. I went through several new ones all delivered with various levels of leakage.

Mine has a petcock on the bottom and a clear vinyl hose on the side that shows you what is in the can.

How about using a fuel filter between PVC and manifold?   ( changing out every oil change)

When I got my Fontana stroker engine back from the vendor/builder there were breathers on the valve covers and no PCV valve, which I had always run on the Cleveland engine. There was a constant mist of oil coming out of those breathers and it was a reminder of what vehicles were like before the PCV. I later soon installed a PCV valve and oil mist catch can and the oil mist problem went away. The PCV was one of the few emissions control devices that actually were a good idea.

@jfb05177 posted:

How about using a fuel filter between PVC and manifold?   ( changing out every oil change)

It will work but I find they are too small.

The Fram HP1 is a good size but  you don't need the expense of the filter element.

What the catch can should do is provide a place for excess oil to accumulate to minimize the amount being drawn into the intake system.

For that the can just needs a screen element on the exit port.

Catch can.