PCV System Question
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
I would still like some feedback from some of the other forum seniors like Lars and BarryK and Norveil before I swap my breather and PCV. I have never had a problem, but if the PCV should be on the drivers side and the breather on the passenger side I will swap it as it wouild be very easy to do so.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by MartyW
I would still like some feedback from some of the other forum seniors like Lars and BarryK and Norveil before I swap my breather and PCV. I have never had a problem, but if the PCV should be on the drivers side and the breather on the passenger side I will swap it as it wouild be very easy to do so.
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
Originally Posted by genuine1980
LARS has already posted and said that it doesn't matter which side its on... I am also hoping for others to chime in, but so far the consenus seems to be that the valve goes on the drivers side and the breather on the pass side.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by MartyW
Lars has had my car in his garage before and he was the one who suggested to put a breather on the drivers side valve cover and leave the PCV connected on the passenger side. I could easily swap the valve covers so I can run the PCV on the drivers side, but I wanted some more confirmations and explanations. I can see how the directional rotation of the crank could make a difference, but then again maybe it doesn't. I have never had a problem, but if there is a reason for it to be on one side vs another...I will change it.
Originally Posted by lars
That is correct - that will work perfectly. As long as the PCV is attached to one valve cover and hooked up to manifoild vacuum, and the opposite cover has provision for air inlet. Your system will work fine.
However, if your crankcase is pressurizing as quickly and strongly as you indicate, you might want to do a cylinder leakdown test to check out those rings. The PCV will help with the blowby, but it won't fix bad or broken rings. If you're blowing oil out your breathers, you might have some ring problems... best check it out.
So I am just waiting it out for a conclusion before I do anything
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
Originally Posted by genuine1980
I am not in disagreement with you, I just want to knw what is right. I know the Lars is very knowlegable, I've read his papers and have a lot of respect for him... all I'm saying is that on this thread he said it doesnt matter what side its on. While others say it does.
Originally Posted by lars
That is correct - that will work perfectly. As long as the PCV is attached to one valve cover and hooked up to manifoild vacuum, and the opposite cover has provision for air inlet. Your system will work fine.
However, if your crankcase is pressurizing as quickly and strongly as you indicate, you might want to do a cylinder leakdown test to check out those rings. The PCV will help with the blowby, but it won't fix bad or broken rings. If you're blowing oil out your breathers, you might have some ring problems... best check it out.
So I am just waiting it out for a conclusion before I do anything
Originally Posted by lars
That is correct - that will work perfectly. As long as the PCV is attached to one valve cover and hooked up to manifoild vacuum, and the opposite cover has provision for air inlet. Your system will work fine.
However, if your crankcase is pressurizing as quickly and strongly as you indicate, you might want to do a cylinder leakdown test to check out those rings. The PCV will help with the blowby, but it won't fix bad or broken rings. If you're blowing oil out your breathers, you might have some ring problems... best check it out.
So I am just waiting it out for a conclusion before I do anything
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Believe me
The PCV valve goes on the drivers side bank and in '76 I believe it also T'd off to the canister on the drivers side
I know that was the case on both my 1973's
You can see it very clearly in my Corvette photos "Holley SA 670" pic
It was not the stock carb at the time but it was setup as it came from the factory
The PCV valve goes on the drivers side bank and in '76 I believe it also T'd off to the canister on the drivers side
I know that was the case on both my 1973's
You can see it very clearly in my Corvette photos "Holley SA 670" pic
It was not the stock carb at the time but it was setup as it came from the factory
Last edited by Bob Onit; Nov 3, 2006 at 07:59 PM.
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
Originally Posted by Bob Onit
Believe me
The PCV valve goes on the drivers side bank and in '76 I believe it also T'd off to the canister on the drivers side
I know that was the case on both my 1973's
You can see it very clearly in my Corvette photos "Holley SA 670" pic
It was not the stock carb at the time but it was setup as it came from the factory
The PCV valve goes on the drivers side bank and in '76 I believe it also T'd off to the canister on the drivers side
I know that was the case on both my 1973's
You can see it very clearly in my Corvette photos "Holley SA 670" pic
It was not the stock carb at the time but it was setup as it came from the factory
I appreciate and definately value your input as well. My 76 has a newer SBC that has centerbolt valve covers and has been bored over and installed with a 385 stroker kit. From the day it was built, the PCV was on the passenger side valve cover. What I think we really need to know here is, does it make a difference what side it is on? Does the PCV really not work if it is connected to the passenger side?
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
I think in most cases the factory put the PCV valve on the drivers side valve cover but as far as I know it shouldn't make a difference which side it's on as long as you have the PCV on one side and connected to the carb and a breather on the other side.
I like doing things the factory way so that's what I usually stick with but as Lars already said it can go on either side.
The idea is to ventilate vapors out of the motor so it's not going to make a difference which way the ventilation os going as long as it has fresh air on one side and the PCV on the other side.
I like doing things the factory way so that's what I usually stick with but as Lars already said it can go on either side.
The idea is to ventilate vapors out of the motor so it's not going to make a difference which way the ventilation os going as long as it has fresh air on one side and the PCV on the other side.
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Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by BarryK
The idea is to ventilate vapors out of the motor so it's not going to make a difference which way the ventilation os going as long as it has fresh air on one side and the PCV on the other side.
If you look at the design of the top end I cant see any difference as far as which bank the PCV is installed on
I was simply stating the factory setup as the canister is mounted on the drivers side which would make it more convient
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
What you are forgetting is the rotation of the crank which acts as a fan in the crankcase, creating some vacuum on passenger's side and some pressure on the driver's side (assuming a normal direction of engine rotation). It's no coincidence Chevy, Ford, Chrysler, Pontiac, Cadillac, and most any other "V" engined car has the PCV valve on the driver's side of the engine.
The valve is a one way valve. Suck on the big end then suck on the smaller end and you'll agree.
Putting the valve on the vacuum bank of the "V" engine, will prevent any flow and your oil will quickly turn to yak, and the junk in the blow-by gases will collect (sludge from polluted oil) and moisture will corrode the crankcase, and as noted earler, a properly running PCV system will help prevent oil leaks.
Does anyone have the diagram that shows the "flow" inside a "V" engine? It would quickly show what apparently I'm unable to explain.
The valve is a one way valve. Suck on the big end then suck on the smaller end and you'll agree.
Putting the valve on the vacuum bank of the "V" engine, will prevent any flow and your oil will quickly turn to yak, and the junk in the blow-by gases will collect (sludge from polluted oil) and moisture will corrode the crankcase, and as noted earler, a properly running PCV system will help prevent oil leaks.
Does anyone have the diagram that shows the "flow" inside a "V" engine? It would quickly show what apparently I'm unable to explain.
Last edited by 73, Dark Blue 454; Nov 4, 2006 at 10:46 AM.
Racer
Joined: Nov 2004
Posts: 432
Likes: 0
From: Granbury TX
Originally Posted by genuine1980
Conflict alert!!!!
Now I don't know what to do.
LOL
Now I don't know what to do.
LOL
air filter with a pcv hole for the little filter inside the
air cleaner. You buy these at any auto store, they are
plastic with a little horse hair filter inside and a c-clip
to attach it to the breather.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Well my mind is made up. I am going to set mine up as 73, Dark Blue 454 says to be on the safe side. If it is later determined that it doesn't matter switch side you set it up on then I did not harm and I will change it at that point.
Pro
Joined: Dec 2005
Posts: 596
Likes: 1
OK I'm back after a full day of throttle romping! Just for my own curiosity I swapped the PCV and breather this morning. After a typical day in the car I always have some oil in the valve cover exterior channels and the breather is soaked with oil, the Pcv is soaked with oil, and I have been frustrated with this from the start.
I added an extra half quart of oil this morning and drove hard and cornered hard all day. My K&N breather and PCV valve were oil free.
I had no new puddling in the cover channels. It may not be the only way to go, but DRIVER PCV and PASSENGER BREATHER fixed my leaking.
The diagrams I looked at in HAYNES manual did not designate front or rear view. The only clue was the throttle linkage, meaning the valve would be driver's side.
Also noted that in the engine compartment layout diagram the PCV valve is located under the hose that ducts hot air off manifold to the breather, or driver's side.
I added an extra half quart of oil this morning and drove hard and cornered hard all day. My K&N breather and PCV valve were oil free.
I had no new puddling in the cover channels. It may not be the only way to go, but DRIVER PCV and PASSENGER BREATHER fixed my leaking.
The diagrams I looked at in HAYNES manual did not designate front or rear view. The only clue was the throttle linkage, meaning the valve would be driver's side.
Also noted that in the engine compartment layout diagram the PCV valve is located under the hose that ducts hot air off manifold to the breather, or driver's side.
Burning Brakes
Joined: Oct 2004
Posts: 763
Likes: 0
From: Loveland Colo
OK, now this discussion leads me to ask, "What is the correct PCV valve to install?" You go to the parts store and there are dozens of PCV valves which all look the same. How are they differentiated? Is there a difference which could help with oil seepage and or correct performance of the system?
My '73 still has the vapor cannister line to the PCV to the carb, on the driver side. The passenger side breather is open to atmosphere, not connected to the air cleaner. I get seepage at both rocker box holes, which I have attributed to my old hand-me-down aluminum Mickey Thompson valve covers which have no oil baffles and less than perfect gasket surfaces.
A big-block Forum member gave a part number a few months back for a "correct" PCV valve for modified big-block engines, but I do not recall that he gave any reasons for his recommendation. I have not yet purchased one so I cannot say if it would help. Seems to me there must be a difference, perhaps in spring weight, for all the different part numbers and applications.
Any thoughts, ideas, info?
John
My '73 still has the vapor cannister line to the PCV to the carb, on the driver side. The passenger side breather is open to atmosphere, not connected to the air cleaner. I get seepage at both rocker box holes, which I have attributed to my old hand-me-down aluminum Mickey Thompson valve covers which have no oil baffles and less than perfect gasket surfaces.
A big-block Forum member gave a part number a few months back for a "correct" PCV valve for modified big-block engines, but I do not recall that he gave any reasons for his recommendation. I have not yet purchased one so I cannot say if it would help. Seems to me there must be a difference, perhaps in spring weight, for all the different part numbers and applications.
Any thoughts, ideas, info?
John
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
Keep in mind that any oil vapor coming out of the crankcase will now be burned in your cylinders, just as if you poured oil down the carb. If it's as steamy as you indicated on the first page, you might keep an eye on those plugs and cylinders. 