No PCV system
Thread Starter
Burning Brakes
Joined: Sep 2010
Posts: 799
Likes: 26
From: Lexington Park Maryland
No PCV system
I noticed this over the weekend during a local event for our veterans (Southern Maryland Crusin for Veterans). Some were Chevrolet cars, some on Hot Rods and other coversion with SBC 350. They did not have the standard PCV on any of their valve cover. what they had was, what I call static breather on both valve cover.
The set up looks cool, because several had the chrome shield around the filter eliment open to one side. So, what is the advantage for not having PCV system and only have these breather.
To my understanding the PCV function is to evacuate the blow by out of the engine, hence the vacuum operated PCV. Having the vacum suck it out is a better application and having the two breath just open, one would think is not as efficient as having it sucked out of the engine.
The set up looks cool, because several had the chrome shield around the filter eliment open to one side. So, what is the advantage for not having PCV system and only have these breather.
To my understanding the PCV function is to evacuate the blow by out of the engine, hence the vacuum operated PCV. Having the vacum suck it out is a better application and having the two breath just open, one would think is not as efficient as having it sucked out of the engine.
Team Owner
Joined: Sep 2006
Posts: 31,267
Likes: 4,362
From: Westminster Maryland
Hi n2v,
The name of the part PVC tells the story.
With a PCV set up the crankcase ventilation is POSITIVE because it's created by the engine's vacuum.
With a breather the ventilation occurs at the whim of the atmosphere.
I think a PVC system has environmental advantages also.
Regards,
Alan
The name of the part PVC tells the story.
With a PCV set up the crankcase ventilation is POSITIVE because it's created by the engine's vacuum.
With a breather the ventilation occurs at the whim of the atmosphere.
I think a PVC system has environmental advantages also.
Regards,
Alan
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Without PCV:
Oil gets contaminated faster. Condensation is not evacuated.
Positive pressure inside the engine makes oil leaks more likely.
I don't think running two breathers looks better. There are matching PCV/Breathers so both sides look the same.
Here's the one I use (Billet Specialties). This is the PCV side, the other side looks exactly the same minus the hose.
Oil gets contaminated faster. Condensation is not evacuated.
Positive pressure inside the engine makes oil leaks more likely.
I don't think running two breathers looks better. There are matching PCV/Breathers so both sides look the same.
Here's the one I use (Billet Specialties). This is the PCV side, the other side looks exactly the same minus the hose.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
actually, older motors had a "road draft tube" that hung down along the side of the motor, and the vapors were drawn out as you were driving, fresh air came in through the breather. obviously it is better emission-wise to reburn the vapors thus the PCV system.
people eliminate the PCV system to make it look cleaner, especially when they don't really drive the vehicle much. I kind doubt there is much if any performance gain...
people eliminate the PCV system to make it look cleaner, especially when they don't really drive the vehicle much. I kind doubt there is much if any performance gain...
Burning Brakes
Joined: Dec 2008
Posts: 971
Likes: 45
From: Middlesex NJ
As mentioned above ... removing the condensate from the engine is a real nice thing. Especially on these cars that dont get used as much as regular drivers in most cases. Pull a valve cover off an engine with no pcv... ill bet you find rust on the rockers (if they are steel of course).
Dual breathers and header scavengers with one way valves where used more on racing to keep the crankcase pressure down so you don't blow out your seals during high revs.
Anyway... I like pcv because it also keeps your engine from getting that fine mist of oil all over it and it seems to cut down on engine smell ... just my .$02
Dual breathers and header scavengers with one way valves where used more on racing to keep the crankcase pressure down so you don't blow out your seals during high revs.
Anyway... I like pcv because it also keeps your engine from getting that fine mist of oil all over it and it seems to cut down on engine smell ... just my .$02
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Factory PCV is a closed system; nothing escapes to the atmosphere. Aftermarket valve cover breathers vent engines gases to the atmosphere.
If you have emissions testing in your state, skip the breathers.
If you have emissions testing in your state, skip the breathers.
Burning Brakes
Joined: Aug 2008
Posts: 878
Likes: 55
From: Deep South Denmark
Ohh no, that was another 77 $ on my Summit wishlist 
http://www.summitracing.com/int/part...0720/overview/
http://www.summitracing.com/int/part...1720/overview/
http://www.summitracing.com/int/part...0720/overview/
http://www.summitracing.com/int/part...1720/overview/
Last edited by Danish Shark; May 28, 2015 at 10:15 AM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
When breathers vent to the atmosphere, that means that all those oil-laden hot vented gasses end up on your engine and compartment surfaces. With a PCV system, those fumes are burned in with the fuel charge. Ergo: Your engine stays cleaner with a working PCV system.
P.S. There is no "downside" to a PCV system. It doesn't rob any power; it just burns up oily fumes from the crankcase.
P.S. There is no "downside" to a PCV system. It doesn't rob any power; it just burns up oily fumes from the crankcase.
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