PCV Questions?
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,909
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From: Clymer PA
PCV Questions?
Ok, I just got my valve covers from Jeg's today. The valve covers do not have holes in them for PCV valve/breather (but there is a spot where you can cut your own hole). I have two questions:
A. Do I need to cut a hole in both valve covers and have a breather/valve in both or would one suffice?
B. I'm thinking I need two PCV breathers/valves so I was wondering....would it be OK to run two PCV breathers and not a PCV valve (or is a PCV valve a must)?
Thanks. :cheers:
A. Do I need to cut a hole in both valve covers and have a breather/valve in both or would one suffice?
B. I'm thinking I need two PCV breathers/valves so I was wondering....would it be OK to run two PCV breathers and not a PCV valve (or is a PCV valve a must)?
Thanks. :cheers:
Drifting
Joined: Oct 2000
Posts: 1,825
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From: Shawano WI
Re: PCV Questions? (bence13_33)
Shane you need to run something to relieve any pressure in the crankcase or you will blow gaskets out. A breather or pcv will work. The drawback to a breather is they tend to drip oil, something you won't want on your new motor. I don't think a breather that goes in the pvc hole would be enough. You will need something larger. I personaly would go with the pvc but the choice is yours. Which ever way you go make sure there is a baffle under it so as not to force oil into it.
Thread Starter
Safety Car
Joined: Aug 2000
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From: Clymer PA
Re: PCV Questions? (Pete79L82)
See that's the thing....these valve covers don't have baffles. They are Comp Polymers and I got them from Jeg's. Whoever designed these valve covers needs to be beat to death with a rubber hose.
Couldn't I run two PCV breathers and put fabric around the breather to catch the oil that comes out? I've seen this done on many engines at car shows. What do you think I should do about the baffle thing? I was a bit puzzled whenever I didn't see them on the valve covers.
Couldn't I run two PCV breathers and put fabric around the breather to catch the oil that comes out? I've seen this done on many engines at car shows. What do you think I should do about the baffle thing? I was a bit puzzled whenever I didn't see them on the valve covers.
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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St. Jude Donor '06-'10, '13
Re: PCV Questions? (Pete79L82)
To have a correct system one valve cover should have a PCV valve, connect that to the carb.
The other valve cover should have a breather.
In a good engine, the carb. provides a vacuum through the PCV that creates a negative pressure in the crankcase. At the same time it draws in oil / fuel vapors to be reburned. The breather alows clean filtered air into the crankcase as a type of cross flow ventilation.
In engines with bad rings and blow-by, the PCV helps seal the system to a point, but not enough. If you have oil on your breather that is because either:
A: your PCV system is not working....
B: your rings are shot and you have too much blow-by for the PCV to keep up with.
Never run a PCV without a filtered breather. If you don't have a PCV, then a filtered breather just acts to be a vent for the crankcase, and that is not the best way to run it.
The other valve cover should have a breather.
In a good engine, the carb. provides a vacuum through the PCV that creates a negative pressure in the crankcase. At the same time it draws in oil / fuel vapors to be reburned. The breather alows clean filtered air into the crankcase as a type of cross flow ventilation.
In engines with bad rings and blow-by, the PCV helps seal the system to a point, but not enough. If you have oil on your breather that is because either:
A: your PCV system is not working....
B: your rings are shot and you have too much blow-by for the PCV to keep up with.
Never run a PCV without a filtered breather. If you don't have a PCV, then a filtered breather just acts to be a vent for the crankcase, and that is not the best way to run it.
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: PCV Questions? (BSeery)
Never run a PCV without a filtered breather.
If I remember right I thought Mr.Gasket of Moroso made a bolt on baffle for breather and pcv's. They do require you to drill holes in your covers though.
Le Mans Master
Joined: Nov 1999
Posts: 5,768
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From: San Diego CA
Re: PCV Questions? (bence13_33)
You definitly want a PCV valve in one cover (drivers usually) and a breather in the other - factory breathers are always filtered - you could install a nice k&n breather in the passenger cover and the pcv in the other and have a good system.
Le Mans Master
Joined: Apr 2000
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From: cincinnati ohio
St. Jude Donor '09
Re: PCV Questions? (bence13_33)
Go to the Summit catalog page and type in "breather baffle" they have a selection of valve cover grommets with integral baffles :yesnod:
I've used them and they work.
Positively do run a pcv system, engine bay stays cleaner, eliminates crankcase fumes from cockpit etc. :cheers:
I've used them and they work.
Positively do run a pcv system, engine bay stays cleaner, eliminates crankcase fumes from cockpit etc. :cheers:
Burning Brakes
Joined: Jul 2001
Posts: 1,160
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From: Ajax Ontario
Re: PCV Questions? (fauxrs)
Agree you want both a PCV in one bank and a filtered breather in the other. Baffle is a necessity or you will suck oil in through the PCV valve. Too bad your covers don't have baffles. If not possible to add, then I'd send them back and request baffled ones.
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Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,909
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From: Clymer PA
Re: PCV Questions? (yellow 72)
Yellow72:
Thanks for the heads up! I guess I'll be getting two valve cover grommets with integral baffles. I'll also be running a PCV valve and breather combination. Thanks for the help guys! :cheers:
Thanks for the heads up! I guess I'll be getting two valve cover grommets with integral baffles. I'll also be running a PCV valve and breather combination. Thanks for the help guys! :cheers:
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
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From: Twin Cities Minnesota
Re: PCV Questions? (bence13_33)
Absolutely, run a breather and a PVC or two PVC's
I ran two breathers for a while but it was pretty stinky :U
Two breathers would be cool, they would create a small vacuum in the crankcase :) Maybe I'll try it this summer...
I ran two breathers for a while but it was pretty stinky :U
Two breathers would be cool, they would create a small vacuum in the crankcase :) Maybe I'll try it this summer...
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
Re: PCV Questions? (427V8)
427, I'm using two breathers and running the PCV directly to the intake from the base of the carb.
I installed a lifter valley baffle to keep oil away from the bottom of the manifold and the PCV valve. I like the setup :cheers:
[Modified by yellow 72, 3:48 PM 3/14/2002]
I installed a lifter valley baffle to keep oil away from the bottom of the manifold and the PCV valve. I like the setup :cheers:
[Modified by yellow 72, 3:48 PM 3/14/2002]
Race Director
Joined: Nov 2000
Posts: 11,872
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From: Waterloo ontario Canada
Re: PCV Questions? (BSeery)
I agree with Bseery. I run a pcv in one valve cover and a hose from my filler spout to inside the air cleaner on the other side. If you run just 2 filters on the valve covers you will get some oil drip and smoking.
As for baffles under the covers I run a stud girdle and it is directly below each hole.
This is a huge picture but shows how I run my breather along with the homemade oil filler and Ford cap.
As for baffles under the covers I run a stud girdle and it is directly below each hole.
This is a huge picture but shows how I run my breather along with the homemade oil filler and Ford cap.
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Re: PCV Questions? (yellow 72)
I like the PCV Yellow72 ! Nice and clean.
Have you run it yet?
I'm wondering if it smokes at all?
Also, what happened to all of you vacuum hoses? My car looks like a snake pit!
[Modified by 427V8, 5:10 PM 3/14/2002]
Have you run it yet?
I'm wondering if it smokes at all?
Also, what happened to all of you vacuum hoses? My car looks like a snake pit!
[Modified by 427V8, 5:10 PM 3/14/2002]
Pro
Joined: Apr 2001
Posts: 591
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From: Morinville Alberta
Re: PCV Questions? (bence13_33)
There are several things to consider
PCV stands for positive crankcase ventilation
So in other words you want to eliminate any back presure you can
and connecting the PCV valve to the carb creates vacume this is what you want. The other side has a breather or is connectd to the air cleaner (more vacume) Vacume helps keep the oil on the right side of the piston rings which is probably why nascar engines have gone to an even more advanced system.
That plus the fact that this vacume actualy helps suck the pistons down and creates a small HP gain. Now I think I might be getting too Deep.
I learnt this lesson back in the days when I had an old civic (Which burnt enough oil as it was) One day I opened the hood and saw a hose off. :confused: So I pluged it
well did it ever smoke then I think I cleared out a whole block. :bb :D :D :crazy:
PCV stands for positive crankcase ventilation
So in other words you want to eliminate any back presure you can
and connecting the PCV valve to the carb creates vacume this is what you want. The other side has a breather or is connectd to the air cleaner (more vacume) Vacume helps keep the oil on the right side of the piston rings which is probably why nascar engines have gone to an even more advanced system.
That plus the fact that this vacume actualy helps suck the pistons down and creates a small HP gain. Now I think I might be getting too Deep.
I learnt this lesson back in the days when I had an old civic (Which burnt enough oil as it was) One day I opened the hood and saw a hose off. :confused: So I pluged it
well did it ever smoke then I think I cleared out a whole block. :bb :D :D :crazy:
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
Re: PCV Questions? (427V8)
427, I ran the same setup with a single plane weiand all summer and it worked great, In my opinion better than one in the cover and the PCV in the other.
Vacuum hoses? Vacuum hoses? we don't need no stinking vacuum hoses.
Actually it's not all together in that pic, but other than the 5/16 vacuum advance for the distributor that's it. PCV + the main vacuum tap for all the "vette" stuff which is teed off the PCV line. That was what I tried to do ,use the bare minimum of lines. :cheers:
Vacuum hoses? Vacuum hoses? we don't need no stinking vacuum hoses.
Actually it's not all together in that pic, but other than the 5/16 vacuum advance for the distributor that's it. PCV + the main vacuum tap for all the "vette" stuff which is teed off the PCV line. That was what I tried to do ,use the bare minimum of lines. :cheers:
