How to remove your PCV.
Originally Posted by MrDude_1
a few other people listed the real, downsides, but i'll list some again anyway.
first you need to know, WHY is the PCV system there??
its NOT for evaporative emissions.. its for the engines oil change life.
the byproducts of combustion, mostly gasses, do get into the crankcase. some of these are acidic, some is water, ect.. the PCV systems job is to remove these crankcase vapors and replace them with clean, fresh air. it is to provide a constant flow of fresh air.. NOT to create a vacuum. yes, it does have a SECONDARY job as a vent, letting off pressure, but the PCV systems primary job is to provide fresh clean air for the crankcase
what happens if the PCV system is removed?
well, assuming you have a breather, you will not have any excess pressure in the crankcase.. thats the route most people take. however, all of the combustion by-products, will make their way into your oil, and slowly increase in there..
your oil should be changed on a VERY VERY frequent basis... otherwise water vapor will condense in it.. and the oil will become slightly acidic and eat at bearings...
why cant i just run breathers, race motors do it??
race cars get their oil changed very frequently. they are inspected and gone over on a very regular basis... if you think about it, this is the same as you getting out and going over your motor ever 5mins of driving... road racers, sports car racing, ect DO run a Positive crankcase vent system... either a conventional one, or a vacuum pump.. its mostly drag racers with the breathers only. and you now know why.
in the 50s, there used to be a hole in the back of the block to act as a vent.... in the early 60s someone invented this neat little one way small orifice valve they called a PCV valve... all of a sudden, oil change intervals were measured in 1000s of miles instead of hundreds... thats how long ago this was discovered, and how long its been around... this basic PCV system exists on every car for the last ~40 years, import, domestic, or whatever.. most motorcycles and even larger engine tools have a PCV system.. and while they vary in orifice size in the valve, they all operate the same basic way.
do NOT remove your PCV valve in a street car... instead, run a LS6 style PCV valley cover... run a air/oil separator.... or just disconnect it at the track, but run with it everyday otherwise...
first you need to know, WHY is the PCV system there??
its NOT for evaporative emissions.. its for the engines oil change life.
the byproducts of combustion, mostly gasses, do get into the crankcase. some of these are acidic, some is water, ect.. the PCV systems job is to remove these crankcase vapors and replace them with clean, fresh air. it is to provide a constant flow of fresh air.. NOT to create a vacuum. yes, it does have a SECONDARY job as a vent, letting off pressure, but the PCV systems primary job is to provide fresh clean air for the crankcase
what happens if the PCV system is removed?
well, assuming you have a breather, you will not have any excess pressure in the crankcase.. thats the route most people take. however, all of the combustion by-products, will make their way into your oil, and slowly increase in there..
your oil should be changed on a VERY VERY frequent basis... otherwise water vapor will condense in it.. and the oil will become slightly acidic and eat at bearings...
why cant i just run breathers, race motors do it??
race cars get their oil changed very frequently. they are inspected and gone over on a very regular basis... if you think about it, this is the same as you getting out and going over your motor ever 5mins of driving... road racers, sports car racing, ect DO run a Positive crankcase vent system... either a conventional one, or a vacuum pump.. its mostly drag racers with the breathers only. and you now know why.
in the 50s, there used to be a hole in the back of the block to act as a vent.... in the early 60s someone invented this neat little one way small orifice valve they called a PCV valve... all of a sudden, oil change intervals were measured in 1000s of miles instead of hundreds... thats how long ago this was discovered, and how long its been around... this basic PCV system exists on every car for the last ~40 years, import, domestic, or whatever.. most motorcycles and even larger engine tools have a PCV system.. and while they vary in orifice size in the valve, they all operate the same basic way.
do NOT remove your PCV valve in a street car... instead, run a LS6 style PCV valley cover... run a air/oil separator.... or just disconnect it at the track, but run with it everyday otherwise...
I tried to tell them.......
http://www.supersixmotorsports.com/pdf/PCV%20Bypass.pdf
Read the 4th paragraph, sounds like an ls1 engine "low tension rings"
Read the 4th paragraph, sounds like an ls1 engine "low tension rings"
Last edited by UltraZLS1; Mar 13, 2006 at 03:14 PM.
Originally Posted by UltraZLS1
http://www.supersixmotorsports.com/pdf/PCV%20Bypass.pdf
Read the 4th paragraph, sounds like an ls1 engine "low tension rings"
Read the 4th paragraph, sounds like an ls1 engine "low tension rings"
i read the 1st paragraph, and could instantly tell the author is ignorant of the real reason the PCV system is there..
i'll repeat it again since some people skip long posts.
THE PRIMARY POURPOSE OF A PCV SYSTEM IS NOT TO RELIEVE PRESSURE. IT IS TO PULL FRESH CLEAN AIR INTO THE CRANKCASE AND REMOVE BLOW-BY GASES...
In my last boosted car I had to change the oil every few hundred miles, but I never did get the oil hot on a regular basis. I always checked the clarity and smell of it and changed when it was dirty or smelly.
TECH Regular
Joined: Aug 2005
Posts: 445
Likes: 0
From: Tampa Bay
Any thoughts on this???
https://ls1tech.com/forums/generation-iii-external-engine/468744-vented-oil-cap.html
https://ls1tech.com/forums/generation-iii-external-engine/468744-vented-oil-cap.html
Originally Posted by FL01SS
if you're running a MAF tune still (and 98% of the people here are) then you shouldnt run a breather..
normal airflow for your LS1 PCV:
your intake air, including the air going into the motor and thru the PCV, goes thru the maf... its metered... (from here on air measured in the MAF is called metered air)
the engine is sealed everywhere except the PCV ports, so as air is pulled out of the crankcase and into the engine, a equal amount of air goes thru the vent into the motor...
because the air going in thru the PCV is equal to the air measured in the metered air, the tune stays accurate.
now if you put a breather in, it pulls UNmetered air in... the air from the breather doesnt go thru the maf, and it goes into the manifold...
this will not drasticly throw off your tune. the engine can compensate... however if you're tuning it yourself, you'll see your MAF table is farther off, and the trims will go off a tad...
so you can do it, but i wont, and i dont reccomend it, simply because it messes with me when im tuning a car.... although i can do it on my own car since i run speed density (aka no MAF tune) half the time...
its late and im watchin TV so i hope that made sence.. lol
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great thread this should be stickyed. Is there a breather than will work that doesn't attach to the top of the plastic stack that the oil cap screws onto? I dont have enough clearence.
Originally Posted by nytoy
great thread this should be stickyed. Is there a breather than will work that doesn't attach to the top of the plastic stack that the oil cap screws onto? I dont have enough clearence.
Staging Lane
Joined: May 2004
Posts: 58
Likes: 0
From: Far North Dallas Denison
Easy and fast fix Just make a call to speedinc. They have everything u need and they pull off the whole pvc system , block or cap t.b. inlet and run a cap over intake inlet and use 2 k&n breathers. Total cost is under $65 and your ready to go! They run on all cars! Hope this helps! The breather have seals and plug right in! easy fix!
Last edited by STREET SHARK; Jul 14, 2006 at 02:38 PM. Reason: misspelled word
Bringin this back I was thinkin of removing my pvc but im not sure yet since it really doesnt cause much clutter but I dont want oil in the intake either. Can I get rid of the blue and red hoses and cap everything off and get a breather for the oil fill cap. Then with the hose in the back that looks yellow can I just remove that and replace it with a hose connecting both valve covers directly that doesnt have the Y that is if the connections are the same size on both valve covers. Thx for the answers in advance.
On The Tree
Joined: Nov 2005
Posts: 172
Likes: 0
From: Maryland
OK so I read this entire thread and it seems to me that the cleanest and most efficient solution is to insert an inline micro mist separator (or a catch can) in the line to the intake manifold. The only question that I have is what is the maximum pressure in that line so the unit can be sized properly. I want to make sure that I don't have the same problem that SUX2BU had with an undersized unit causing his seals to blow.
Does anyone know what the maximum pressure for the PCV?
Does anyone know what the maximum pressure for the PCV?
Staging Lane
Joined: Nov 2003
Posts: 90
Likes: 0
i have a vaccum leak in the y at the valve cover cross over lines in the rear of the intake,i found it while i was removing the intake to clean it,i'm also chasing a knock problem,has anyone else replaced the y with another vaccum y fitting?
Originally Posted by bluenyghthawk
what if you put a small breather on the hose that comes from the trottle body and capped off the throttle body nipple?
You can run a PCV system with a catch can, cap off the fresh air inlet, and run a breather just fine as long as you tune for it. Personally I prefer just that since it allows the crankcase to still be positively evacuated, your breathers don't get all nasty all the time from oil vapors, and it still allows excess pressure to be completely vented with no pressure build up. You just have to properly compensate for it in the tune. If you are running speed density than no changes are really necessary unless you are exceeding your IAC counts. If you have a MAF just throw a bit more in the idle and part throttle areas of the MAF table to get your fuel trims back in line and it works just fine. A closed PCV system is just an air leak that is metered, an open PCV system is one isn't metered with the MAF but is easily compensated for regardless. Now you guys can continue arguing over which is better, I know what I prefer.
why would you have a vacum leak the other end goes into the valve cover and your nipple coming off of your throttle body would be caped youd still get air when needed and it would leak into your intake