Turbo and PCV?
09-19-2017, 03:55 PM
#1
Turbo and PCV? I have searched and read about this alot. I can't seem to find any solid info or agreement, like most things I research 
I have a S475 with a SBE 6.0
I've just finally got to where I can start getting into a little boost. (Not sure how much because I had to send my AEM boost gauge back for repairs today, it was bad right out of the box). My best guess is around 5 to 7 lbs as I used the lighter springs in my wastegates....
I noticed today that The O ring under the oil fill tube was bulged out..... Also noticed that I'm getting some oil in the charge pipes....... I have had the PCV hooked up UNTIL I noticed this today and I have now disconnected it and am venting to atmosphere.
I have read that this will possibly give you that stinky oil smell and you will no longer have the PCV pulling water condensation out of the oil......
Can someone please break it down into complete noob terms for this novice 1st time turbo guy?
My options are either vent to atmosphere or setup a catch can right????? And you shouldn't use a PCV system when you have boost from a turbo or supercharger because you are starting to pressurize the crankcase???? Do I have this right?
Please you guys, take me to school on this issue, I want to learn.
I have a S475 with a SBE 6.0
I've just finally got to where I can start getting into a little boost. (Not sure how much because I had to send my AEM boost gauge back for repairs today, it was bad right out of the box). My best guess is around 5 to 7 lbs as I used the lighter springs in my wastegates....
I noticed today that The O ring under the oil fill tube was bulged out..... Also noticed that I'm getting some oil in the charge pipes....... I have had the PCV hooked up UNTIL I noticed this today and I have now disconnected it and am venting to atmosphere.
I have read that this will possibly give you that stinky oil smell and you will no longer have the PCV pulling water condensation out of the oil......
Can someone please break it down into complete noob terms for this novice 1st time turbo guy?
My options are either vent to atmosphere or setup a catch can right????? And you shouldn't use a PCV system when you have boost from a turbo or supercharger because you are starting to pressurize the crankcase???? Do I have this right?
Please you guys, take me to school on this issue, I want to learn.
09-19-2017, 04:06 PM
#2
So you can have several options for crank case ventilation.
-Open Breathers
-Race/Draft Can
-PCV Can
I know plenty of guys who have breathers on each valve cover and that's it.
They don't really notice an oil smell but they do get an oil film surrounding the breathers which is why you see a rag wrapped around open breathers.
The other option is a catch can, pony up and buy the Mighty Mouse unit and while your at it ask David what he recommends for your particular setup.
David has extensive knowledge regarding PCV system architecture and he'll guide you in the right direction.
Am improperly sized/setup vent system will still cause issues, ask me how I know lol.
If your wanting to avoid the oil smell and keep clean air flowing through your crankcase which extends oil life and what not then a PCV system is what you need and again, contact David at Mighty Mouse.
-Open Breathers
-Race/Draft Can
-PCV Can
I know plenty of guys who have breathers on each valve cover and that's it.
They don't really notice an oil smell but they do get an oil film surrounding the breathers which is why you see a rag wrapped around open breathers.
The other option is a catch can, pony up and buy the Mighty Mouse unit and while your at it ask David what he recommends for your particular setup.
David has extensive knowledge regarding PCV system architecture and he'll guide you in the right direction.
Am improperly sized/setup vent system will still cause issues, ask me how I know lol.
If your wanting to avoid the oil smell and keep clean air flowing through your crankcase which extends oil life and what not then a PCV system is what you need and again, contact David at Mighty Mouse.
09-19-2017, 04:16 PM
#3
Holy fast reply Batman!
Ok this helps alot thankyou! For now, I will just be venting with open breathers. It's funny you mentioned Mighty Mouse, I was just looking at David's website earlier this afternoon!! And more than likely I will be contacting him to purchase a can system of some type.
Do you think that having the stock PCV system connected was what caused the oil fill tube O ring to bulge out??? The stock PCV system was pressurizing the crankcase a little bit????
Thanks for the reply, I have read many of your other posts and learned from all of them.
Ok this helps alot thankyou! For now, I will just be venting with open breathers. It's funny you mentioned Mighty Mouse, I was just looking at David's website earlier this afternoon!! And more than likely I will be contacting him to purchase a can system of some type.
Do you think that having the stock PCV system connected was what caused the oil fill tube O ring to bulge out??? The stock PCV system was pressurizing the crankcase a little bit????
Thanks for the reply, I have read many of your other posts and learned from all of them.
09-19-2017, 04:19 PM
#4
11 Second Club
iTrader: (3)
10 AN lines off the valve covers to a breather can.
09-19-2017, 04:31 PM
#5
Holy fast reply Batman!
Ok this helps alot thankyou! For now, I will just be venting with open breathers. It's funny you mentioned Mighty Mouse, I was just looking at David's website earlier this afternoon!! And more than likely I will be contacting him to purchase a can system of some type.
Do you think that having the stock PCV system connected was what caused the oil fill tube O ring to bulge out??? The stock PCV system was pressurizing the crankcase a little bit????
Thanks for the reply, I have read many of your other posts and learned from all of them.
Ok this helps alot thankyou! For now, I will just be venting with open breathers. It's funny you mentioned Mighty Mouse, I was just looking at David's website earlier this afternoon!! And more than likely I will be contacting him to purchase a can system of some type.
Do you think that having the stock PCV system connected was what caused the oil fill tube O ring to bulge out??? The stock PCV system was pressurizing the crankcase a little bit????
Thanks for the reply, I have read many of your other posts and learned from all of them.
I've got too small of lines on my catch can setup currently and at 12 lbs. it pushed my dipstick out and made a huge oily mess lol.
The PCV system is one of those items I feel like its okay to go a little overkill on.
I'll be using a -12 AN to one side of the can and using the other side as directed with 3/8" line going to the manifold vacuum.
It's definitely overkill but I don't want to do it again when I turn the boost up more.
This arrangement gets me no oily smell and clean air in the crank case, win win baby!
09-19-2017, 04:59 PM
#6
That looks real clean. Gives me ideas how I might setup a can when I do install one. Is that pushlock hose on there?
Ok I'm glad to know! Like I said this is my first turbo build so it's been one hell of a learning curve for me 
This build has actually been a lot of firsts for me, using AN line and fittings for example.
How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
Definitely.
I've got too small of lines on my catch can setup currently and at 12 lbs. it pushed my dipstick out and made a huge oily mess lol.
The PCV system is one of those items I feel like its okay to go a little overkill on.
I'll be using a -12 AN to one side of the can and using the other side as directed with 3/8" line going to the manifold vacuum.
It's definitely overkill but I don't want to do it again when I turn the boost up more.
This arrangement gets me no oily smell and clean air in the crank case, win win baby!
I've got too small of lines on my catch can setup currently and at 12 lbs. it pushed my dipstick out and made a huge oily mess lol.
The PCV system is one of those items I feel like its okay to go a little overkill on.
I'll be using a -12 AN to one side of the can and using the other side as directed with 3/8" line going to the manifold vacuum.
It's definitely overkill but I don't want to do it again when I turn the boost up more.
This arrangement gets me no oily smell and clean air in the crank case, win win baby!
This build has actually been a lot of firsts for me, using AN line and fittings for example.How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
09-19-2017, 06:35 PM
#7
if you care about the engine you will connect a PCV valve to the intake manifold and let it draw on the crankcase. The air inlet to the crankcase to replace what is lost to the intake manifold comes from the compressor inlet (pre-turbo) but AFTER the air cleaner (so clean filtered air goes into the crankcase).
We consider the crankcase closed in true high mileage daily driver applications, so no large flow is necessary. More flow may be required if crankcase blow-by is increased beyond high mileage acceptable limits which vary person to person opinion. Usually small/tiny lines suffice for low-blowby engines which have low flow requirements in their crankcases. The reason we do not use super-tiny lines is because they might clog, which can be catastrophic. So use a large enough line that you are confident it will not, will never clog. Do not worry about "flow" because there is minimal flow.
More info:
The combustion process produces byproducts some of which passes piston rings. These products either remain as a gas state or become solvated by engine oil as part of the liquid. Any gas state molecules are able to "vacuumed" out of the crankcase by PCV action, which will reduce their influence on engine oil quality. Combustion byproduct typically reduces the quality of engine oil, all factory engine are equipped with some form of PCV system to ensure longest-life oil service intervals and minimal engine wear. For a similar reason all OEM vehicles are equipped with paper style air filters-but that is another discussion.
We consider the crankcase closed in true high mileage daily driver applications, so no large flow is necessary. More flow may be required if crankcase blow-by is increased beyond high mileage acceptable limits which vary person to person opinion. Usually small/tiny lines suffice for low-blowby engines which have low flow requirements in their crankcases. The reason we do not use super-tiny lines is because they might clog, which can be catastrophic. So use a large enough line that you are confident it will not, will never clog. Do not worry about "flow" because there is minimal flow.
More info:
The combustion process produces byproducts some of which passes piston rings. These products either remain as a gas state or become solvated by engine oil as part of the liquid. Any gas state molecules are able to "vacuumed" out of the crankcase by PCV action, which will reduce their influence on engine oil quality. Combustion byproduct typically reduces the quality of engine oil, all factory engine are equipped with some form of PCV system to ensure longest-life oil service intervals and minimal engine wear. For a similar reason all OEM vehicles are equipped with paper style air filters-but that is another discussion.
Last edited by kingtal0n; 09-19-2017 at 06:43 PM.
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09-19-2017, 10:25 PM
#9
You don't have any part numbers or sources for which you bought those oil fill to AN adapters do you? I'm finding some on Fleabay but just curious......
What purpose does the steel wool serve?
It looks like your MAP sensor hold down is exactly the same as the one I made to hold my ZR1 map sensor in. Is that a ZR1 map???
09-19-2017, 10:49 PM
#10
The adapters are from Hawksmotorsports on eBay. About $35 a piece. Don’t worry about stealing my idea, go for it! The steel wool keeps any oil residue from contaminating or coming out of the breather. The map sensor was an Ls1 style map from EFI source. I was worried about it blowing out under boost so I made the little bracket to hold it down. I’ve since moved on to a billet Holley map that’s 1/8 npt and it’s treaded into the vacuum log you can see on the firewall.
09-20-2017, 10:18 AM
#12
11 Second Club
iTrader: (3)
That looks real clean. Gives me ideas how I might setup a can when I do install one. Is that pushlock hose on there?
Ok I'm glad to know! Like I said this is my first turbo build so it's been one hell of a learning curve for me This build has actually been a lot of firsts for me, using AN line and fittings for example.
How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
Ok I'm glad to know! Like I said this is my first turbo build so it's been one hell of a learning curve for me
This build has actually been a lot of firsts for me, using AN line and fittings for example.How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
09-20-2017, 11:45 AM
#13
That looks real clean. Gives me ideas how I might setup a can when I do install one. Is that pushlock hose on there?
Ok I'm glad to know! Like I said this is my first turbo build so it's been one hell of a learning curve for me This build has actually been a lot of firsts for me, using AN line and fittings for example.
How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
Ok I'm glad to know! Like I said this is my first turbo build so it's been one hell of a learning curve for me
This build has actually been a lot of firsts for me, using AN line and fittings for example.How big are your lines? Were you worried about blowing a timing cover or rear main seal when you pushed the dipstick out at 12PSI?
If you get a chance post up pics of your setup. I'm definitely a visual person and I'd love to see how you setup your system.
I feel like I got lucky just blowing out the dipstick and no other damage occurred, it didn't help that I was in 5th gear at full song trying to run down a N20 vette lol.
My system ties into the factory PCV system and pics do no good because you can't see anything.
I'd suggest either a setup like 3 Windows or a MM PCV setup.
MM has a 3 port PCV can that would enable you to run a -10 from each valve cover and then run a 3/8" line to a manifold vacuum source for PCV operation which to me is ideal but 3 Windows setup is probably a lot more cost effective.
09-20-2017, 11:48 AM
#14
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The best solution is a vacuum pump. PCV valves only draw vacuum when your engine is making intake manifold vacuum, which is when you really don't need as much venting because your engine is making less blow-by. PCV valves also introduce oil into your combustion chambers which lowers the octane of your fuel,and causes detonation.
Pressure in your crankcase not only causes oil leaks, it can also force oil past your valve guides and into your combustion chambers.
Catch cans work if you have large enough tubes running from your engine to them to maintain no positive pressure. The hoses need to be larger than you would think.
A vacuum pump will stop oil leaks, add horsepower, keep your oil cleaner, and prevent oil in your combustion chambers.
Pressure in your crankcase not only causes oil leaks, it can also force oil past your valve guides and into your combustion chambers.
Catch cans work if you have large enough tubes running from your engine to them to maintain no positive pressure. The hoses need to be larger than you would think.
A vacuum pump will stop oil leaks, add horsepower, keep your oil cleaner, and prevent oil in your combustion chambers.
09-20-2017, 12:57 PM
#15
The adapters are from Hawksmotorsports on eBay. About $35 a piece. Don’t worry about stealing my idea, go for it! The steel wool keeps any oil residue from contaminating or coming out of the breather. The map sensor was an Ls1 style map from EFI source. I was worried about it blowing out under boost so I made the little bracket to hold it down. I’ve since moved on to a billet Holley map that’s 1/8 npt and it’s treaded into the vacuum log you can see on the firewall.
Right on!
I'm currently running 3/8" line throughout which is waaaaay too small.
I feel like I got lucky just blowing out the dipstick and no other damage occurred, it didn't help that I was in 5th gear at full song trying to run down a N20 vette lol.
My system ties into the factory PCV system and pics do no good because you can't see anything.
I'd suggest either a setup like 3 Windows or a MM PCV setup.
MM has a 3 port PCV can that would enable you to run a -10 from each valve cover and then run a 3/8" line to a manifold vacuum source for PCV operation which to me is ideal but 3 Windows setup is probably a lot more cost effective.
I feel like I got lucky just blowing out the dipstick and no other damage occurred, it didn't help that I was in 5th gear at full song trying to run down a N20 vette lol.
My system ties into the factory PCV system and pics do no good because you can't see anything.
I'd suggest either a setup like 3 Windows or a MM PCV setup.
MM has a 3 port PCV can that would enable you to run a -10 from each valve cover and then run a 3/8" line to a manifold vacuum source for PCV operation which to me is ideal but 3 Windows setup is probably a lot more cost effective.
The best solution is a vacuum pump. PCV valves only draw vacuum when your engine is making intake manifold vacuum, which is when you really don't need as much venting because your engine is making less blow-by. PCV valves also introduce oil into your combustion chambers which lowers the octane of your fuel,and causes detonation.
Pressure in your crankcase not only causes oil leaks, it can also force oil past your valve guides and into your combustion chambers.
Catch cans work if you have large enough tubes running from your engine to them to maintain no positive pressure. The hoses need to be larger than you would think.
A vacuum pump will stop oil leaks, add horsepower, keep your oil cleaner, and prevent oil in your combustion chambers.
Pressure in your crankcase not only causes oil leaks, it can also force oil past your valve guides and into your combustion chambers.
Catch cans work if you have large enough tubes running from your engine to them to maintain no positive pressure. The hoses need to be larger than you would think.
A vacuum pump will stop oil leaks, add horsepower, keep your oil cleaner, and prevent oil in your combustion chambers.
09-20-2017, 01:17 PM
#16
I orig ran the LS6 valley cover and used that PCV setup-I was getting oil in the intake, so I added an oil sep, later moved the PCV to the valve cover, and got very little oil in the sep.
I also added a check valve so I didn't blow boost back in the engine
I also added a check valve so I didn't blow boost back in the engine
09-20-2017, 10:03 PM
#19
