Anyone use a DF-17 adjustable PCV?

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DrCharles

DrCharles

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In my never-ending quest for improved idle and just-off-idle manners (big cam 451, 8" vacuum), I'm considering investing in an M/E Wagner DF-17 tunable PCV valve.

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

But that little billet piece is $129.99... before I spend that much, I'd like to hear from anyone who's actually used one, and did it help?
thanks.
 
Couldn't you simply put this .90 cent valve in line and close or open until you get the effect you want??

5688b48376cd142a4392e3f9-large.jpg


Or a needle valve version??
46425k12p1-c03a-digital@1x_637044276840828890.png
 
I have one but yet to set it up. I few others here have them so someone will chime in.

A check valve operates differently than needle valve or fixed ball valve.
 
Kind of missing the point here... the amount of blowby changes with rpm and load. So does the vacuum. And the volume of air going into the engine obviously varies too, so running the blowby back into the intake would change the AFR.
A fixed valve can be adjusted to work at one point on the curve only - which can be at idle, of course. But tip-in is important too.
 
DrCharles said:
Kind of missing the point here... the amount of blowby changes with rpm and load. So does the vacuum. And the volume of air going into the engine obviously varies too, so running the blowby back into the intake would change the AFR.
A fixed valve can be adjusted to work at one point on the curve only - which can be at idle, of course. But tip-in is important too.
Click to expand...


Yep. I’m so glad I bought mine. I was ridiculed on this very site for a long time because I recommend everyone run a PCV valve AND they get the Wagner valve and be done with it.

Too many don’t know the difference between price and value.
 
yellow rose said:
Yep. I’m so glad I bought mine. I was ridiculed on this very site for a long time because I recommend everyone run a PCV valve AND they get the Wagner valve and be done with it.

Too many don’t know the difference between price and value.
Click to expand...

I was frankly shocked at the directions supplied. I've never seen instruction so well written and laid out. Everything you need to know about the valve, setting it up and service parts. Defiantly done by an engineer/car gut buy easy to understand and follow.
 
yellow rose said:
I recommend everyone run a PCV valve AND they get the Wagner valve and be done with it.
Click to expand...

I suspect that this valve would fix my tip-in lean spot. It's just as the throttle starts to open. No amount of messing with pump linkage, squirters, t-slot restrictors, IFR etc. could completely get rid of it. I think my "whatever Autozone PVC valve fits the cover" is causing the problem since idle vacuum is already only 8".
 
I forgot to say that you've got to run a shielded cable from the accelerator linkage to the lever on the valve. This will compensate for changes in crankcase pressure relative to rpm/load.
:rofl:
 
Last edited:
DrCharles said:
Kind of missing the point here... the amount of blowby changes with rpm and load. So does the vacuum. And the volume of air going into the engine obviously varies too, so running the blowby back into the intake would change the AFR.
A fixed valve can be adjusted to work at one point on the curve only - which can be at idle, of course. But tip-in is important too.
Click to expand...
Check the ME wagner instructions. My recollection is that on low vacuum engines, the recommendation is to set it up with the fixed orifice.
In which case you can test your theory by experimenting with a fixed orifice in the same situations where its dying now.
Posted some ballpark fixed diameter sizes here, which will give you a starting point.
PCV Flow Rates
 
Mattax said:
Check the ME wagner instructions. My recollection is that on low vacuum engines, the recommendation is to set it up with the fixed orifice.
Click to expand...
True, and I already checked them :)
7-10", use the dual adjustable;
Below 7", use the fixed orifice.
Mine idles at 8" and cruises at 15"...
 
DrCharles said:
In my never-ending quest for improved idle and just-off-idle manners (big cam 451, 8" vacuum), I'm considering investing in an M/E Wagner DF-17 tunable PCV valve.

Dual Flow Adjustable PCV Valve – M/E Wagner Performance Products

But that little billet piece is $129.99... before I spend that much, I'd like to hear from anyone who's actually used one, and did it help?
thanks.
Click to expand...


I have one and I don't think much of it. It should work but I think they made it too complicated so it is actually kind of hard to figure out. I ended up making a fixed orifice PCV which works just fine. A fixed orifice setup actually works really well with a big cam and it shouldn't require too much work to make one.
 
AndyF said:
I have one and I don't think much of it. It should work but I think they made it too complicated so it is actually kind of hard to figure out. I ended up making a fixed orifice PCV which works just fine. A fixed orifice setup actually works really well with a big cam and it shouldn't require too much work to make one.
Click to expand...

I read these posts with some Interest , I experimented w/ pcv`s and cover to air breather lines on my 505 , still dont understand all/much of it .
My engine definitly didnt like the cover to air cleaner hose with pcv on the other cover. , ACTED LIKE A VACUUM LEAK , which is interesting , cause I dont have any oil at the valvecover breathers when I tried them, even built an oil catch can ,nothing showed up in it . been running 2 pcv`s , now one on each cover , both are full intake fed /under the blades , which creates 6'' of crankcase vacuum. IT HAS 9-16 INCHES OF INTAKE VACUUM , depending on throttle opening . I tried a crankcase evac set up on the drivers side w/ the the pcv`s on the other side , dropped my crankcase vacuum to about 1 1/2'' .
I`m thinking of plugging the pcv`S off and running the crankcase evac at the strip only-------I dont have any engine oil leaks running the pcv valves and like that set up -------------all thots and comments appreciated ---bob
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Incedently , I just put a 1/2'' spacer under the throttle body on the victor intake , seems to really like it , I`ve always thot the plenum on the victor was too small------???.
 
I built an high compression old school car and ran the PVC to the exhaust just past the headers. The exhaust creates a vacuum at the valve cover that increases with RPM.
 
Treblig said:
I forgot to say that you've got to run a shielded cable from the accelerator linkage to the lever on the valve. This will compensate for changes in crankcase pressure relative to rpm/load.
:rofl:
Click to expand...

Or hook it up to a rheostat inside the car so you can manually adjust as you put your foot to the floorboard!!!!!!
 
famous bob said:
I tried a crankcase evac set up on the drivers side w/ the the pcv`s on the other side , dropped my crankcase vacuum to about 1 1/2''
Click to expand...
yellow rose said:
I run both a PCV and Pan evac’s.
Click to expand...

I got a question;
If the CC vacuum drops to 1.5, and the intake, at WOT is say 1.0,
wouldn't the PCV be at or near wide open?
And if it was, wouldn't the E-vacs be pulling A/F mixture from the throttle bores, into and thru the CC?
And if that happens; how dangerous might that be?
 
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