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PCV and crankcase pressure.........experts come in

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Old 03-31-2010, 03:31 PM
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Default PCV and crankcase pressure.........experts come in

I have been batteling my 416 since it was new on pressure and how to run a PCV set up. Seems all I do nothing works, because I think I vent to the atmosphere. Scoggin Dickey said you need the P in the PCV...positive pressure. I have tried these methods..

intake capped off - breather catch can going to the valve cover and valley cover.

intake to catch can - catch can to valley - valve cover capped off.

intake to catch can - catch can to valley - valve cover to a fresh air source to the air bridge.

I also read, and think...the stock LS1 set up had the hose going to the air filter, but if its before the MAF, isnt that unmettered air?

Seems to let out smoke everytime I rail on it. Besides a vac pump, what method can be used to create more positive pressure to suck that oil back down?

Thoughts?
Old 03-31-2010, 03:36 PM
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Try Intake to catch can, both valve connected to it Have the vac source on top and the lines for the dirty on bottom. Place a breather on the oil cap. that one tube u refering to is the a.i.r pump its for emmisions. also is it drinking oil? Plus 3/8 hose will work just fine no skinny **** lol.
Old 03-31-2010, 03:46 PM
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Originally Posted by OUTLAWZ RACING
Try Intake to catch can, both valve connected to it Have the vac source on top and the lines for the dirty on bottom. Place a breather on the oil cap. that one tube u refering to is the a.i.r pump its for emmisions. also is it drinking oil? Plus 3/8 hose will work just fine no skinny **** lol.
and what to do with the valley cover tube?

by both valve you mean run them as the dirty side, or tied into the hose for the intake?
Old 03-31-2010, 04:32 PM
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No need for a breather if you're using a catch can IMO...The pass. side valve goes to the air bridge and the driver's side gets capped off.....What type of hose are you using??

intake to catch can - catch can to valley - valve cover to a fresh air source to the air bridge after the MAF...
Old 03-31-2010, 06:18 PM
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Originally Posted by VGLNTE1
I have been batteling my 416 since it was new on pressure and how to run a PCV set up. Seems all I do nothing works, because I think I vent to the atmosphere. Scoggin Dickey said you need the P in the PCV...positive pressure. I have tried these methods..

intake capped off - breather catch can going to the valve cover and valley cover.

intake to catch can - catch can to valley - valve cover capped off.

intake to catch can - catch can to valley - valve cover to a fresh air source to the air bridge.

I also read, and think...the stock LS1 set up had the hose going to the air filter, but if its before the MAF, isnt that unmettered air?

Seems to let out smoke everytime I rail on it. Besides a vac pump, what method can be used to create more positive pressure to suck that oil back down?

Thoughts?
Ths whole subject depends on how much, if any, blow-by you have. If your engine is very tight, then you should have the "P" in PCV. So just set up a stock type PCV system.
If your engine is not very tight then you have no use for the "P", it will just suck a ton of oil out of your crankcase and thats not good. The normal pull of vacuum is WAY TOO MUCH if your engine is not tight. It will need to be adjusted like I did for mine. My system works great and almost stopped all my fuel burn issue.

Here's mine below. I simply pull vacuum from the passenger side valve cover, and have a breather on the rear of the drivers side valve cover. So I pull fresh air in, it crosses the entire engine and it gets pulled out of the passengers side valve cover. BUT....I have the vacuum strength dialed down using that T-valve and metering screw. I capped the valley cover port...I personally think pulling vacuum from there (on a bow-by engine) pulls way too much oil from the crankcase.

.
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Old 03-31-2010, 06:47 PM
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Originally Posted by VGLNTE1
and what to do with the valley cover tube?

by both valve you mean run them as the dirty side, or tied into the hose for the intake?
If your using the bridge from the driver side then cap off the front port on the passenger head. The bridge should connect to both valve covers and shoud be one line in the catch can. For the valley cover that can be the second line to the catch can. then use the stock line of the intacke to connect to the top of the catch can. Then place a breather on top where the oil cap goes. The motor would pull vacume through the breather. If your blowing smoke out the dip stick tube than u have a ring problem. But it has to do it when u rev on it. and u will notice it because it will be alot.
Old 03-31-2010, 07:10 PM
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Originally Posted by LS6427
Ths whole subject depends on how much, if any, blow-by you have. If your engine is very tight, then you should have the "P" in PCV. So just set up a stock type PCV system.
If your engine is not very tight then you have no use for the "P", it will just suck a ton of oil out of your crankcase and thats not good. The normal pull of vacuum is WAY TOO MUCH if your engine is not tight. It will need to be adjusted like I did for mine. My system works great and almost stopped all my fuel burn issue.

Here's mine below. I simply pull vacuum from the passenger side valve cover, and have a breather on the rear of the drivers side valve cover. So I pull fresh air in, it crosses the entire engine and it gets pulled out of the passengers side valve cover. BUT....I have the vacuum strength dialed down using that T-valve and metering screw. I capped the valley cover port...I personally think pulling vacuum from there (on a bow-by engine) pulls way too much oil from the crankcase.

.
I think I have a very loose engine, and it blows a ton...so the port on my valley does puke a lot. When I had the passenger side valve cover to the air bridge, it puke oil into that. I fear if i hook it up like you do, I will just suck oil from the valve cover to the intake.

do you have a valve in that tube from the intake to the valve?
Old 03-31-2010, 07:49 PM
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Originally Posted by VGLNTE1
I think I have a very loose engine, and it blows a ton...so the port on my valley does puke a lot. When I had the passenger side valve cover to the air bridge, it puke oil into that. I fear if i hook it up like you do, I will just suck oil from the valve cover to the intake.

do you have a valve in that tube from the intake to the valve?
There's nobody on this forum, I don't think, that has a street driven daily driver with more blow-by than me. I have a 4.125 stroke in old short 2001 LS1 sleeves......and 140,000+ miles on my engine.

It will work good for you. I put a clear hose on there to see iany oil gets sucked in like that and I saw none. Hooked up normally to the valley cover port, it sucks up alot constantly. What I did was the fix for an engine wih aot of blow-by.

And yes....you can see the metal torques bolt I put in that T-valve to open up the vacuum as much as I want, or totally close it off if I want.

.
Old 03-31-2010, 07:54 PM
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vacuum pump will fix all that.

http://www.gzmotorsports.com/LSXVPK.html
Old 03-31-2010, 08:39 PM
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Originally Posted by LS6427
There's nobody on this forum, I don't think, that has a street driven daily driver with more blow-by than me. I have a 4.125 stroke in old short 2001 LS1 sleeves......and 140,000+ miles on my engine.

It will work good for you. I put a clear hose on there to see iany oil gets sucked in like that and I saw none. Hooked up normally to the valley cover port, it sucks up alot constantly. What I did was the fix for an engine wih aot of blow-by.

And yes....you can see the metal torques bolt I put in that T-valve to open up the vacuum as much as I want, or totally close it off if I want.

.
Well, I will give it a try..but, whats the point of the screw? when would you want less or more blowby?
Old 04-01-2010, 12:04 AM
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Originally Posted by VGLNTE1
Well, I will give it a try..but, whats the point of the screw? when would you want less or more blowby?
It doesn't allow more or less blow-by. By unscrewing it a little bit the intake vacuum will pull harder and suck more crankcase gases through the passengers side port. If I screw it in I just decrease that suction.

The suction from the intake is just too much I think, so I leave it at a setting thats about 1/3 strength of factory stock suction. It pulls plenty but not too much where I suck oil from my crankcase. Theres no need for a catch can, just turn down the suction and its perfect. I never have any moisture in my crankcase.

.
Old 04-01-2010, 05:47 AM
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Originally Posted by LS6427
It doesn't allow more or less blow-by. By unscrewing it a little bit the intake vacuum will pull harder and suck more crankcase gases through the passengers side port. If I screw it in I just decrease that suction.

The suction from the intake is just too much I think, so I leave it at a setting thats about 1/3 strength of factory stock suction. It pulls plenty but not too much where I suck oil from my crankcase. Theres no need for a catch can, just turn down the suction and its perfect. I never have any moisture in my crankcase.

.
do you have a PCV valve in that hose as well? Can tell if thats just a fitting or the stock looking valve.



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