Adjustable PVC valve?

[Brads70]

Beneficial or snake oil ? 

http://mewagner.com/?p=444

[Chryco Psycho]

I can see benefits to a tunable PCV

[bcudachris]

I run one.  230/.550ish cam.  I doubt it'll speed anyone up on the street or anything, BUT, once I got it properly tuned for idle flow and cruise channel opening, my plugs are nice and clean and it isn't pulling as much oil into the catch can under street driving conditions.  The real benefit that I see (or don't see) is that the engine has pretty much zero oil seepage.  Not around the breather or PCV grommets, not around the dip stick tube and bone dry rear main.

My only complaint is their tuning instructions give guidelines based on CID of the engine.  I have a 408 and run a Kevko 5qt pan and they list a huge adjustment range for the 400ci engines.  For that reason, I had a pretty long learning curve with it.  It seems to me flow rate would largely be determined by crankcase volume and you'd be a lot closer right off the bat if you could calculate your starting point based on that rather than on piston displacement.  Not that I blame Wagner for not wanting to figure out the correct info to provide.

The other thing I would recommend is don't use one on a new engine.  What works at 50 miles is a vacuum leak at 800.

[gzig5]

I've read only complimentary things about them but don't have any first hand experience.  I will probably go with one when I build my motor.  If nothing else, they add a little high tech bling to a modified engine compartment.