When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I did a search on PCV valves and valve covers with baffles and there is some great information on this site. So before I make a mistake I need a little more info on my future set up if possible. I have a 69 442 with a 1971 455, and the current PCV looks right and functions properly with the M/T covers which I believe have the baffles. This is how I got the car and have not played with anything under the hood yet. I would like to install these Edelbrock valve covers which do not have baffles and the billet breather and PCV which I purchased separately. I tried to do a search for baffles for these covers but came up empty. I also have roller rockers so I'm not sure on clearance. I'm wondering if this set up will work the way I want it or if I need to possibly use a grommet with baffle? How would that work, first the baffle grommet then the PCV into that?
First picture- where does the rubber tube go? I ask because it's connected to a PCV breather filter, not a PCV valve. If the hose is connected to a vacuum port that's a huge vacuum leak. If it's connected to an outside air source you're good.
Or is there a PCV valve stuck into the rubber elbow?
Been years since I had any custom valve covers so not sure what type baffles are in the PCV valve and breather openings.
Last edited by rocketraider; November 2nd, 2021 at 02:46 PM.
First picture- where does the rubber tube go? I ask because it's connected to a PCV breather filter, not a PCV valve. If the hose is connected to a vacuum port that's a huge vacuum leak. If it's connected to an outside air source you're good.
Or is there a PCV valve stuck into the rubber elbow?
Been years since I had any custom valve covers so not sure what type baffles are in the PCV valve and breather openings.
It goes to back of carb, yes PCV is in the elbow.
Last edited by tt455; November 2nd, 2021 at 03:44 PM.
Reason: correcting answer
It goes to back of carb, PCV is in the grommet to the cover.
To Glenn's point, that isn't where the PCV valve goes. The black breather connects to the air filter housing with a metal tube. The PCV valve goes in the opposite valve cover in a dedicated grommet.
And since the next question will be about the drawing below, the use of two breathers was only on manual trans cars.
[QUOTE=joe_padavano;1381046]To Glenn's point, that isn't where the PCV valve goes. The black breather connects to the air filter housing with a metal tube. The PCV valve goes in the opposite valve cover in a dedicated grommet.
And since the next question will be about the drawing below, the use of two breathers was only on manual trans cars.
Joe, there is an aftermarket air cleaner. There's no hole on the other cover. So I corrected my answer to Glenn, the PCV valve is in the elbow, no metal tube, hose goes to back of carb. No good? The car runs good no oil leaks, future problems? Learning as we go on, I
I'm used to PCV valves in the intake. Thanks everyone for your responses.
Joe, his current setup, as creative as it may be, is to keep oil out of the PCV. I doubt purity was a factor.
Good point, but unfortunately there's no breather to let air into the PCV system. The valve is vacuum pulling fumes OUT of the engine. This inlet can be a breather on the oil fill tube, or a breather in the other valve cover. FYI, aftermarket air cleaners like that all come with a knockout on the bottom that will accept the tube from the other breather.
Not to hijack this thread, but my current setup is a vacuum hose going from the PCV valve on the passenger side valve cover to a port on the carb, and I also have an oil breather on the other valve cover. Is this acceptable?
Last edited by 72455; November 2nd, 2021 at 06:31 PM.
Why not just fabricate your own baffle plate to fit the area that's setup for one using those 6 screw holes?
Yes was thinking that. I guess a flat piece of metal with some spacers?
No additional spacers are required, the screw hole standoffs that are molded into the VC are the spacers. If you notice with the addition of a plate there is only an opening at one end that is out of the oil spray of the rockers. That will be enough to allow gasses to escape without oil being sucked into the valve.
72455- your system will work fine as it has a crankcase fresh air intake and a PCV valve to meter blowby gas for reburn.
You might want to look into the nipple Joe P posted. Attaches to air cleaner baseplate and turns it into a closed PCV system. Get a MoPar or Ford style breather cap with a nipple and connect a hose between it and air cleaner. That will reduce oil film buildup around the valve cover breather.
72455- your system will work fine as it has a crankcase fresh air intake and a PCV valve to meter blowby gas for reburn.
You might want to look into the nipple Joe P posted. Attaches to air cleaner baseplate and turns it into a closed PCV system. Get a MoPar or Ford style breather cap with a nipple and connect a hose between it and air cleaner. That will reduce oil film buildup around the valve cover breather.
TT455----your Edlebrock valve covers are similar on the bottom side to the M/T ones that I used for my roller rocker setup on my recent engine build. Mine also did not have the baffles on the underneath so I made them out of thin metal. I tapped the holes in the bosses that were part of the valve cover casting and then installed small screws with lock-tite into those holes. They work great. I did have the dual breather setup with the hoses and metal pipes connecting to the air cleaner but recently went another route and switched to what you see in the attached pics. I now have two stand-alone breathers and use the factory style PCV with the elbow as noted in the post.
There are several ways this can be done....just depends on your preferences for the look, originality, and functionality.
Latest engine photos with dual snorkel air cleaner and breathers. Also shows factory style PCV with elbow. High flow air breather....left bank. High flow air breather....right bank.
TT455----your Edlebrock valve covers are similar on the bottom side to the M/T ones that I used for my roller rocker setup on my recent engine build. Mine also did not have the baffles on the underneath so I made them out of thin metal. I tapped the holes in the bosses that were part of the valve cover casting and then installed small screws with lock-tite into those holes. They work great. I did have the dual breather setup with the hoses and metal pipes connecting to the air cleaner but recently went another route and switched to what you see in the attached pics. I now have two stand-alone breathers and use the factory style PCV with the elbow as noted in the post.
There are several ways this can be done....just depends on your preferences for the look, originality, and functionality.
Latest engine photos with dual snorkel air cleaner and breathers. Also shows factory style PCV with elbow.
High flow air breather....left bank.
High flow air breather....right bank.
Nicely done, thanks for posting. I love your wire loom set up, did you fabricate those or are they available? Ty, Tom.
I would do a search for vertical spark plug wire looms for an Olds 455. I believe I ordered mine from Summit and they are identical to these---if I remember correctly.
To Glenn's point, that isn't where the PCV valve goes. The black breather connects to the air filter housing with a metal tube. The PCV valve goes in the opposite valve cover in a dedicated grommet.
And since the next question will be about the drawing below, the use of two breathers was only on manual trans cars.
Curious on the relationship (I guess GM's though process) between a manual transmission and the need for two breathers in the PCV setup?
Curious on the relationship (I guess GM's though process) between a manual transmission and the need for two breathers in the PCV setup?
This question comes up a lot (since it was also used on the 1969 H/O and the 1970-72 W-30 cars with both trans types). Unfortunately, I have not seen an answer. It might be related to the larger than normal piston-to-wall clearances on the W-motors, or excessive overlap in the cams? I'm just guessing on those, however.
I would do a search for vertical spark plug wire looms for an Olds 455. I believe I ordered mine from Summit and they are identical to these---if I remember correctly.
This question comes up a lot (since it was also used on the 1969 H/O and the 1970-72 W-30 cars with both trans types). Unfortunately, I have not seen an answer. It might be related to the larger than normal piston-to-wall clearances on the W-motors, or excessive overlap in the cams? I'm just guessing on those, however.
Joe, I've read, heard, and I'm quoting here that Hi Performance engines operate at higher rpm, and much higher cylinder pressures, so there is naturally more blow by, which is why all performance engines should have at least two valve cover vents. I'm not sure what it has to do with Olds manual cars though? Tom.
Last edited by tt455; November 7th, 2021 at 08:14 PM.
Thanks to Eric and 442 dude for your suggestions on the baffle. I tapped the holes and cut out a piece of aluminum used some lock-tite on the screws and I'm in business.
November 2nd, 2021, 01:00 PM
