PCV System Question
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
PCV System Question
When I got my car it had no PCV valve or hose going to the carb. Both valve covers have breathers.
Is this OK? I've noticed that the breathers after awhile get oil all up in them.
Additionally... IF I was to connect a PCV Valve and Hose to the carb... the carb has the connection (which has a rubber stop in it right now) on the pass side. Usually I see the stuff all on the drivers side.
????
Thanks
Rich
Is this OK? I've noticed that the breathers after awhile get oil all up in them.
Additionally... IF I was to connect a PCV Valve and Hose to the carb... the carb has the connection (which has a rubber stop in it right now) on the pass side. Usually I see the stuff all on the drivers side.
????
Thanks
Rich
Le Mans Master
Joined: Apr 2004
Posts: 7,106
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From: Newark DE
if I'm not mistaken having breathers on both sides work "ok" but it's not as good or efficent of a system as the correct closed system.
You should have a tube on the passenger side valve cover that goes to the aircleaner housing for fresh air intake - or at the very least a filtered breather, than a PCV valve on the driver's side valve cover that attaches to a vacuum hose that will connect to a port on the carb
You should have a tube on the passenger side valve cover that goes to the aircleaner housing for fresh air intake - or at the very least a filtered breather, than a PCV valve on the driver's side valve cover that attaches to a vacuum hose that will connect to a port on the carb
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
For the system to work, you really nned the pcv system to work. Two vents is better than none, but not as good as one with a vacuum source on the other side.
Over time, you'll probably find that both vents will clog with oil and start to leak oil on te outside.
Over time, you'll probably find that both vents will clog with oil and start to leak oil on te outside.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by Jud Chapin
Just curious, but don't you have emissions testing in PA? If so, I'm supprised you get thru with your set up.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by BarryK
if I'm not mistaken having breathers on both sides work "ok" but it's not as good or efficent of a system as the correct closed system.
You should have a tube on the passenger side valve cover that goes to the aircleaner housing for fresh air intake - or at the very least a filtered breather, than a PCV valve on the driver's side valve cover that attaches to a vacuum hose that will connect to a port on the carb
You should have a tube on the passenger side valve cover that goes to the aircleaner housing for fresh air intake - or at the very least a filtered breather, than a PCV valve on the driver's side valve cover that attaches to a vacuum hose that will connect to a port on the carb
Get a PCV valve and connect it to where the pass side breather is currently. Connect the PCV valve with the correct side vaccum hose to the port on the carb with is currently blocked. On the Driv side, keep the breather.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
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From: Austin TX
Page 4-6 of your Chilton's manual has good diagram of the the "PCV System Flow" through the engine. Air needs to be drawn 'in' from the passenger's side valve cover (from the air cleaner via a tube or 3/4" molded rubber hose) and the blow-by gases need to be purged 'out' from the driver's side valve cover where Chevy placed the PCV valve and plumbing to the carb, which sucks pressure from the crank-case and prevents oil leaks and prevents the nasty blow-by gases from escaping into the atmosphere and your engine bay.
Breathers work ok, but they're messy (is crud accumulating near the breathers?), and I've always thought they looked "Bubba" on street motors (my opinion, but I usaully yield to GM's design,..others are more inclined to 'customize' than I).
Breathers work ok, but they're messy (is crud accumulating near the breathers?), and I've always thought they looked "Bubba" on street motors (my opinion, but I usaully yield to GM's design,..others are more inclined to 'customize' than I).
Le Mans Master
Joined: Dec 2003
Posts: 5,727
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From: Fremont CA
Not having a PCV system will cause rapid oil degredation due to fuel/H2O dillution of the oil. The PCV system does little to hurt the performance of an engine and because of the oil life benefits, it should be installed. The breather can be left in place but, a vent inside the aircleaner helps reduce emissions from the motor with little perfomance penalty.
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Le Mans Master
Joined: Oct 2002
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From: Las Vegas - Just stop perpetuating myths please.
This topic gets answered nearly weeky here on the forum. U really need to try an archive search on this Rich. Then if u have any specific questions we could be more help.
cardo0
cardo0
Le Mans Master
Joined: Apr 2004
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From: Newark DE
Originally Posted by genuine1980
Ok so here is what I think your telling me to do.
Get a PCV valve and connect it to where the pass side breather is currently. Connect the PCV valve with the correct side vaccum hose to the port on the carb with is currently blocked. On the Driv side, keep the breather.
Get a PCV valve and connect it to where the pass side breather is currently. Connect the PCV valve with the correct side vaccum hose to the port on the carb with is currently blocked. On the Driv side, keep the breather.
On the PASSENGER side valve cover is a tube that goes to the aircleaner housing.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
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From: Palm City, FL
Originally Posted by 73, Dark Blue 454
Page 4-6 of your Chilton's manual has good diagram of the the "PCV System Flow" through the engine. Air needs to be drawn 'in' from the passenger's side valve cover (from the air cleaner via a tube or 3/4" molded rubber hose) and the blow-by gases need to be purged 'out' from the driver's side valve cover where Chevy placed the PCV valve and plumbing to the carb, which sucks pressure from the crank-case and prevents oil leaks and prevents the nasty blow-by gases from escaping into the atmosphere and your engine bay.
Breathers work ok, but they're messy (is crud accumulating near the breathers?), and I've always thought they looked "Bubba" on street motors (my opinion, but I usaully yield to GM's design,..others are more inclined to 'customize' than I).
Breathers work ok, but they're messy (is crud accumulating near the breathers?), and I've always thought they looked "Bubba" on street motors (my opinion, but I usaully yield to GM's design,..others are more inclined to 'customize' than I).
As is it now I see gas comming out of both breathers. If I take the breathers off and put my hand over the hole I feel gas building up. Oil leaks etc. I don't like it.
I just want to make sure I connect it right and what I do doesn't screw anything up. My air cleaner has no place to hook up PCV. So I want to be sure that it will be OK putting the valve on the pass side and connecting it directly to the carb, sucking gas out an into the carb, and having the breather on the drivers side that would now be sucking clean air in.
Race Director
Joined: Sep 2001
Posts: 10,560
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From: Wellington, FL
St. Jude Donor '11 thru '25
Originally Posted by genuine1980
In PA "Antique" cars are exempt from Inspection all together (Emission and Safety), and "Classic cars are exempt from Emission but not safety. I have my car registered as antique. I think Classic cars have to be at least 15 yrs old and antique have to be at least 25 years old.
Tech Contributor
Joined: Aug 1999
Posts: 14,376
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From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by genuine1980
I just want to make sure I connect it right and what I do doesn't screw anything up. My air cleaner has no place to hook up PCV. So I want to be sure that it will be OK putting the valve on the pass side and connecting it directly to the carb, sucking gas out an into the carb, and having the breather on the drivers side that would now be sucking clean air in.
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.
Melting Slicks
Joined: May 2005
Posts: 2,152
Likes: 33
From: Folsom Ca
Originally Posted by Jud Chapin
Thanks for the info. It's good they're looking out for the older collectibles.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by 8T Shark
Yeah My uncle has a 79 Trans Am that is registered as Classic back in Pa..there may be a limit on the miles your supposed to drive Im not sure..but I am jealous...damn Cali...
If PA re-elects this dumb *** govenor we currently have, we might be looking at strick restrictions on all our cars including classics and antiques.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
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From: Palm City, FL
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.
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.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Genuine80 and Lars,
The PCV valve won't work on the passenger's side valve cover. On that side of the engine, air needs to be pulled "in" due to the rotational direction of the crank. The PCV valve, being a valve, is designed to allow blow-by gases 'out' and block flow "in", and the since there's suction on that side of the engine, it won't work properly.
At worst, put the breather on the passenger's side (since your air cleaner doesn't have a PCV provision) and the PCV valve on the driver's side valve cover. Then run a 3/8 inch fuel hose to a big port at the base of your carb. There are those who say the vacuum source is not to be shared with the same vacuum source as the brake booster. It's thought these blow-by gases can reduce the life of the booster.
Again,..take a look at the diagram in the Chilton's manual, page 4-6,..it shows how air and gases flow from the passenger's side of the engine to the driver's side. Or perhaps somebody has a diagram they could post.
Good luck!
The PCV valve won't work on the passenger's side valve cover. On that side of the engine, air needs to be pulled "in" due to the rotational direction of the crank. The PCV valve, being a valve, is designed to allow blow-by gases 'out' and block flow "in", and the since there's suction on that side of the engine, it won't work properly.
At worst, put the breather on the passenger's side (since your air cleaner doesn't have a PCV provision) and the PCV valve on the driver's side valve cover. Then run a 3/8 inch fuel hose to a big port at the base of your carb. There are those who say the vacuum source is not to be shared with the same vacuum source as the brake booster. It's thought these blow-by gases can reduce the life of the booster.
Again,..take a look at the diagram in the Chilton's manual, page 4-6,..it shows how air and gases flow from the passenger's side of the engine to the driver's side. Or perhaps somebody has a diagram they could post.
Good luck!
Last edited by 73, Dark Blue 454; Nov 3, 2006 at 05:01 PM.
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
My 385 Stroker was built with the PCV on the passenger side and a breather line connected to the air cleaner on the drivers side. I have replaced the hose that connected to the air cleaner and just run a breather on the drivers's side. I have not have any problems and the breather is not getting messed up with oil or anything.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by 73, Dark Blue 454
Genuine80 and Lars,
The PCV valve won't work on the passenger's side valve cover. On that side of the engine, air needs to be pulled "in" due to the rotational direction of the crank. The PCV valve, being a valve, is designed to allow blow-by gases 'out' and block flow "in", and the since there's suction on that side of the engine, it won't work properly.
At worst, put the breather on the passenger's side (since your air cleaner doesn't have a PCV provision) and the PCV valve on the driver's side valve cover. Then run a 3/8 inch fuel hose to a big port at the base of your carb. There are those who say the vacuum source is not to be shared with the same vacuum source as the brake booster. It's thought these blow-by gases can reduce the life of the booster.
Again,..take a look at the diagram in the Chilton's manual, page 4-6,..it shows how air and gases flow from the passenger's side of the engine to the driver's side. Or perhaps somebody has a diagram they could post.
Good luck!
The PCV valve won't work on the passenger's side valve cover. On that side of the engine, air needs to be pulled "in" due to the rotational direction of the crank. The PCV valve, being a valve, is designed to allow blow-by gases 'out' and block flow "in", and the since there's suction on that side of the engine, it won't work properly.
At worst, put the breather on the passenger's side (since your air cleaner doesn't have a PCV provision) and the PCV valve on the driver's side valve cover. Then run a 3/8 inch fuel hose to a big port at the base of your carb. There are those who say the vacuum source is not to be shared with the same vacuum source as the brake booster. It's thought these blow-by gases can reduce the life of the booster.
Again,..take a look at the diagram in the Chilton's manual, page 4-6,..it shows how air and gases flow from the passenger's side of the engine to the driver's side. Or perhaps somebody has a diagram they could post.
Good luck!
Now I don't know what to do.
LOL
Pro
Joined: Dec 2005
Posts: 596
Likes: 1
OK I Just checked the A.I.M. For a '79 they do show the valve on the driver's side and the return line out of the air cleaner on the pass. side.
Good Info 454-- Thank you! Mine's backwards and has always been a problem. I put extended tubes on my valve and breather to try and remedy the oil flow. Another good find on the forum!!!
Good Info 454-- Thank you! Mine's backwards and has always been a problem. I put extended tubes on my valve and breather to try and remedy the oil flow. Another good find on the forum!!!