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I am running a 306 with forged internals, edelbrock heads and an On3 turbo kit. Though they get bashed quite a bit, I have had no issues with mine. This motor went together a little loose. My piston to wall clearance is anywhere from .050 to .018. I have been told, and from what Im learning in a turbo set up I do not want to run a pcv system? What I don't know is if the smoke Im seeing coming out the breather at this catch can is blowby, or smoke in the engine that has nowhere to go due to a not so adequate pcs/vent situation? What I have is a 5/8 hose and fitting coming off the back of the intake where the pcv would be going into a catch can with a filter on top. I have it mounted behind the strut tower on the passenger side. There are times when the smoke is just pouring out from under the hood on that side. I also notice when it idles for too long it will start to smoke out the exhaust, especially if I hammer down on it, but it will usual clear itself out. I believe that's a problem in the center section of the turbo leaking oil though. I have the passenger valve cover sealed off due to no room to put a breather, or even a cap on it cause the throttle cable bracket is in the way. On the drivers valve cover I am just running a filter type breather. I have been going through the forums and there is a lot of information that contradicts itself. Is it possible this is not blow by I am seeing and pressure build up in the engine? I had a nice set of trickflow valve covers with a bunge welded in for a nice fitting but they would clear the intake. When I put the spacer in it wouldn't clear the hood..I have a cool set of Ford Motorsport Valve Covers but for some reason the angle at the upper corners is cust weird and the rockers hit the cover. Any help on whet to do would be appreciated...a pic to steer me in the right direction would be helpful to.
 

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Discussion Starter #3
The smoke out the exhaust turns into a thick, kinda dirty white smoke. As it sits and idles it tends to get worse and worse. Once I take off it seems to clear itself out. Im assuming this is more of
a problem with the center section of the turbo leaking? The catch can is more of a clear white smoke. Its embarrassing due to the fact the can mounted behind the passenger front strut tower and the smoke will billow out between the hood and fender at that side.
 

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the info on the PCV system is very clear, I don't see where you got confused.

Most don't prepare themselves for the eventuality that pressurizing the long intake tract and increased cylinder pressure will develop MORE than stock blowby with it being difficult to get fresh air into the crankcase.

You need to decide, do you want a PCV system?

or a NON PCV system, and deal with the mess and fumes......
 

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^
Or do a PROPER evac system.
 

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yes you want a pcv system, it will reduce windage, reduce emissions, reduce leaks and reduce rotating assembly resistance, its free power

youll need two check valves and two catch cans to properly set it up

heres the details

Pre Tune Information / EFIDynoTuning
 

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From my personal experience:

I originally blocked off the PCV valve had a vented catch can with a line coming off of each valve cover. I never had the blowby issues you are having but I did notice that my oil got dirty petty quick with the catch can. Also, if there is no way to pull the combustion gases out of the crankcase, like a proper PCV system does, these gases settle onto internal engine parts and into the oil. This will cause engine parts to corrode over time. Like this:



I installed a modified PCV system on my draw thru turbo car. I used a Turbo Coupe PCV valve which has a check that is not supposed to allow boost into the crankcase. In testing it worked properly about 50% of the time. I still used it (will probably go back and gut this valve) and ran a 3/8" line off of it to an oil seperator like this one: JEGS Performance Products 52205, JEGS Air Oil Separator | JEGS Performance Products. From the other side of the seperator the line goes to this check valve: McMaster-Carr which is very well built and will not let boost pressure back into the crankcase. From there it splits into two 3/8" lines that run to the intake.

To pull fresh metered air into the crankcase, I used the factory nipple off of the passenger side valve cover and ran a line into the piping after the mass air meter. I installed an inline fuel filter like this one: http://www.autozone.com/filters-and-pcv/fuel-filter/duralast-fuel-filter/246927_0_0/ just in case to keep anything out of the intake tract. The filter is hidden under the front fender because it would look terrible if not.

I then installed this in place of my sealed factory oil cap: http://www.c-f-m.com/performanceparts/pc/viewPrd.asp?idproduct=3206. This oil cap/breather has an internal check ball and is baffled. It seals off under vacuum and does not allow unmetered air into the system. When in boost it opens and vents any crankcase pressure. It is a high quality piece and works well.

I now have a closed PCV system on my boosted car that works like factory. This setup works perfectly on my car since it is draw thru. On a blow thru system the metered fresh air would have to come from a different (non boosted) source like the inlet of the turbo/supercharger.
 

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PCV removes moisture

and all the bad things associated with what moisture in the crankcase does

A vent does NOT remove moisture.
 
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If a vent tube relieves blow by pressure, but does not remove contaniments or moisture.
What does a PCV system do under boost where blow-by pressure becomes a problem?
 

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when out of boost, PCV becomes active

If you are in boost 100% of the time, you will need an evac system, belt or electric powered.

There are a lot of factory turbo cars out there, that run a PCV

think like them
 

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This is a fact.
I learned this with my rear mount turbo as it has its own set of challenges to keep from boosting the bottom end.
I tried no pcv valve and venting, but the smell was terrible at times and the oil turned black very quickly.

I'm of the opinion venting is a short term solution, and a pcv system is the real solution.
I learned this the hard way.
 

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when out of boost, PCV becomes active

If you are in boost 100% of the time, you will need an evac system, belt or electric powered.

There are a lot of factory turbo cars out there, that run a PCV

think like them
Thanks, but whos question were you attempting to answer? Because that was not an answer to the question I asked.

When in boost, where blow by occurred, what does a PCV do? That's the question.

Blow by has caused mine & others cars to blow out seals and leak oil. The vent tube has corrected this issue.

So again under boost what will a PCV do? If it closes and does nothing, how is that doing anything to help vent crank case pressure? And there by helping my non-factory turbo car retain seated seals?
 

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Thanks, but whos question were you attempting to answer? Because that was not an answer to the question I asked.

When in boost, where blow by occurred, what does a PCV do? That's the question.

Blow by has caused mine & others cars to blow out seals and leak oil. The vent tube has corrected this issue.

So again under boost what will a PCV do? If it closes and does nothing, how is that doing anything to help vent crank case pressure? And there by helping my non-factory turbo car retain seated seals?
Its obvious the PCV will be closed, and I was answering your question, when not in boost the PCV will functional

So, you are in boost 100% of the time?

If so, YOU have to come up with a better system, if you would like to retain the PCV system,,,,,,,,,, like I suggested
 

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Discussion Starter #16
Wow..lots of information and I appreciate it. I have always assumed that the excessive smoke I am seeing is blow by only because this motor was put together a tad loose. Is it possible the smoke I am seeing is not necessarily blow by and just the crank case venting poorly? My current set up is no pcv, but a line coming off the lower intake where the pcv would be going to a catch can. I have some aftermarket valve covers and on the passenger side I am just running a cap. The oil fill hole rides right below the throttle cable bracket so no room to put a filter there. The drivers side I am just running a small filter...not a lot of room their either due to the silly intake hovers just above the opening. The original reason I posted was I was curious if the smoke I am seeing is blowby or could it be the crankcase venting.
 

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Its obvious the PCV will be closed, and I was answering your question, when not in boost the PCV will functional

So, you are in boost 100% of the time?

If so, YOU have to come up with a better system, if you would like to retain the PCV system,,,,,,,,,, like I suggested
Oh, guess I didn't know pressure caused by blow-by that pushes out oil seals.
Only happens if someone is in boost 100% of the time.

Thought it only took 1 time.

So the guys that had to resort to vent tubes to combat crank case pressure must be the guys in boost 100% of the time. And a PCV will solve the blowing out of seals. Which is the reason they went to the vent tube in the first place.

At least we know the remedy (PCV) will cure the symptom.

That clears it up!
 

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The PCV is/has to be closed under boost, therefore inoperable. The system I use works both ways. In vacuum the PCV works normally and removes moisture and combustion gases. When in boost my inline check valve keeps pressure from entering the crankcase through the PCV valve and the check valve opens on the oil filler cap to relieve any pressure in the crankcase and keep it from blowing out seals.

You have to have an escape route for any crankcase pressure that occurs while under boost. Otherwise oil leaks will happen. On the other hand, you can't have an open breather and a PCV system at the same time without having a huge vacuum leak when unmetered air is pulled through the open breather, through the PCV valve, and into the intake. This is where the check ball in the breather I listed earlier comes into play. It seals under vacuum and vents under boost. Best of both worlds. No oil leaks, no vacuum leaks, and a functioning PCV system.
 

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Wow..lots of information and I appreciate it. I have always assumed that the excessive smoke I am seeing is blow by only because this motor was put together a tad loose. Is it possible the smoke I am seeing is not necessarily blow by and just the crank case venting poorly? My current set up is no pcv, but a line coming off the lower intake where the pcv would be going to a catch can. I have some aftermarket valve covers and on the passenger side I am just running a cap. The oil fill hole rides right below the throttle cable bracket so no room to put a filter there. The drivers side I am just running a small filter...not a lot of room their either due to the silly intake hovers just above the opening. The original reason I posted was I was curious if the smoke I am seeing is blowby or could it be the crankcase venting.
With as much smoke as you have going, it has a ton of blowby just idling. I don't think anything short of rebuilding or replacing the bottom end is going to help you.
 

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PCV removes moisture

and all the bad things associated with what moisture in the crankcase does

A vent does NOT remove moisture.
I can agree with this. As soon as I fire my car up, the air/oil separator starts to fog up with moisture. It's doing its job.
 
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