PCV system. Do I need it now?
05-13-2006, 01:31 AM
#1
PCV system. Do I need it now? I have a breather filter on the back of my driverside valve cover where the PCV used to hook up. I now have the LS6 PCV system with a catchcan between the valley cover and the intake, then the one line going from the passenger valvecover to the TB. Do I need any of the PCV system stuff, I mean can I plug up the TB, intake, valley, and valvecover and be ok, or will the breather filter not provide enough ventilation for the crank?
05-13-2006, 01:44 AM
#2
The more I look at that line going from the valve cover to the TB, especially looking at how the machining looks on my NW 90, I have come to the conclusion that it's for sucking fresh air into the MOTOR. This explains why I've heard it called "the fresh air tube" before. I would not remove this tube if I were you.
As for the other system, I think you should go with one or the other. I like the breathers on racecars, catchcans on street cars. If it's working good, keep it the way it is, no reason to change it.
As for the other system, I think you should go with one or the other. I like the breathers on racecars, catchcans on street cars. If it's working good, keep it the way it is, no reason to change it.
05-15-2006, 08:14 PM
#5
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I still get oil past the catch can even with the LS6 PCV swap and a low milage forged block. I run a breather on the passenger cover as well cause I've blown the front crank seal 3 times with the use of a little N20.
I have considered pulling all the PCV stuff off and run 2 breathers (one on each cover) to see how that works out.
A buddy of mine running well over the 500++RWHP N/A is actually blowing oil past the valve cover seal on the driver side.
Dan
I have considered pulling all the PCV stuff off and run 2 breathers (one on each cover) to see how that works out.
A buddy of mine running well over the 500++RWHP N/A is actually blowing oil past the valve cover seal on the driver side.
Dan
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05-16-2006, 09:45 AM
#9
Originally Posted by DanZ28
A buddy of mine running well over the 500++RWHP N/A is actually blowing oil past the valve cover seal on the driver side.
Dan
Dan
05-16-2006, 02:26 PM
#10
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My pcv system is gone. One breather on the passenger side cover and the engine is running perfectly.
Small-blocks (mild to wild) have been running single breathers since 1955 with zero issues. There are pushrod holes in the block that lets bank-to-bank pressure equalize immediately.
If you have enough piston ring blow-by where a single breather can't evacuate gasses fast enough then you have some serious piston ring issues.
BTW.... it's nice not having a single drop of oil in the intake manifold when you take the throttle body off for a peak inside.
Plus it looks much cleaner without all the pcv clutter.
Small-blocks (mild to wild) have been running single breathers since 1955 with zero issues. There are pushrod holes in the block that lets bank-to-bank pressure equalize immediately.
If you have enough piston ring blow-by where a single breather can't evacuate gasses fast enough then you have some serious piston ring issues.
BTW.... it's nice not having a single drop of oil in the intake manifold when you take the throttle body off for a peak inside.
Plus it looks much cleaner without all the pcv clutter.
05-16-2006, 02:59 PM
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you just love to show that off dont you, I cant say i wouldnt if i spent day after day on it for months!!!!!!! but its so gorgeous pm me the name of that polish again becuase i got somethin that looked like it and you use it the same way but all it did is take off a layer of alluminum...
05-16-2006, 03:17 PM
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Originally Posted by CNVRTmyZ
you just love to show that off dont you, I cant say i wouldnt if i spent day after day on it for months!!!!!!! but its so gorgeous pm me the name of that polish again becuase i got somethin that looked like it and you use it the same way but all it did is take off a layer of alluminum...
05-16-2006, 03:24 PM
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Originally Posted by Z'mnypit
With or without the breather mod?
05-16-2006, 03:51 PM
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Originally Posted by DanZ28
Thats with the breather mod on both valve covers, oil is even being puked out of the breather. Judging by what's happening, it doesn't appear to have equal pressure on both sides. Car has alot of mods and puts down quite a bit of HP, so maybe this is exceptional. The engine is pretty new and there is no problems with piston rings. Car runs 10.1's N/A right now with a few issues.
If I put the same breather sticking directly into the valvecover it would be swallowing gobs of oil because of the angle/trajectory.
Perhaps you need to put a baffle in the breather to stop from it from swallowing oil. even with mine on the chiney and a homemade baffle in the breather it will still have splatter after a day of abusive driving.
Not because of pressure, but because of a flurry of oil and the angle of the pushrod hole squirting oil and the opening on the valve cover.
05-16-2006, 03:58 PM
#15
Originally Posted by TheBlurLS1
The more I look at that line going from the valve cover to the TB, especially looking at how the machining looks on my NW 90, I have come to the conclusion that it's for sucking fresh air into the MOTOR. This explains why I've heard it called "the fresh air tube" before. I would not remove this tube if I were you.
As for the other system, I think you should go with one or the other. I like the breathers on racecars, catchcans on street cars. If it's working good, keep it the way it is, no reason to change it.
As for the other system, I think you should go with one or the other. I like the breathers on racecars, catchcans on street cars. If it's working good, keep it the way it is, no reason to change it.
thats because 90% of the PCV systems job is to carry fresh air into the crankcase to displace blowby gasses.... a mere 10% of its job is to relieve crankcase pressure.... but most people dont bother figuring out WHY its there.. they just go by the "logic" of "if it works for racecars..."
05-16-2006, 04:34 PM
#17
How does the PCV system get "fresh" air into the crankcase? It seems that the crankcase is pressurized (blowing) and the top of the motor has a vacuum (sucking). How do you get air to flow from the sucking side into the pressurized side? Not trying to be a smart *** or anything, I just want to understand as it sounds impossible to me.
05-16-2006, 09:57 PM
#19
Originally Posted by MrDude_1
thats because 90% of the PCV systems job is to carry fresh air into the crankcase to displace blowby gasses.... a mere 10% of its job is to relieve crankcase pressure.... but most people dont bother figuring out WHY its there.. they just go by the "logic" of "if it works for racecars..."
05-17-2006, 01:17 AM
#20
Originally Posted by MrDude_1
thats because 90% of the PCV systems job is to carry fresh air into the crankcase to displace blowby gasses.... a mere 10% of its job is to relieve crankcase pressure.... but most people dont bother figuring out WHY its there.. they just go by the "logic" of "if it works for racecars..."
