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By Kingfisher - 2 Years Ago
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I sorta hate to add another PCV question! There are plenty of threads and I reckon I've read most of them but can't quite find the answer.
I have an ACE finned valley cover to put on my 312 with a grommet and valve to suit. The cover comes with a PCV provision - a circular flat area ready to be machined out and 2 posts on the underside which presumably could be drilled and tapped to screw on a baffle (not sure I would be comfortable with the possibility of dropping a screw).
What configuration should the baffle be? I imagine something like Mummert's maybe, but I can't see a decent photo of his. Is it sealed on just 2 sides, allowing airflow in through the outer 2 edges? Or is another design better? And what about the large vertical baffle that the stock cover comes with? I gather it's not particularly necessary?
(It's interesting that they put a baffle below the filler though)
Thanks, Mark
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By Ted - 2 Years Ago
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See if these help.
FoMoCo 1958-1964 valley cover
Mummert valley cover with PCV valve
Mummert valley cover without PCV valve
Blue Thunder valley cover with PCV valve
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By 55blacktie - 2 Years Ago
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Kingfisher, I have the same Ace valley cover. Ace told me that they don't install a baffle due to various lengths of pcv valves. I would think if you Loctite the screws or use high-temp epoxy, whatever baffle you use should be secure. I've also considered removing the sheet metal baffle from my original valley cover and tack-welding it to the Ace valley cover. Let me know what you come up with, including photo, and what pcv valve you're using.
Thanks.
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By MoonShadow - 2 Years Ago
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You could install the sheet metal cover from a stock cover with screws and then spot weld the screws to the cover so they couldn't work loose.
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By Kingfisher - 2 Years Ago
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Thanks Ted, very helpful. What's the welded nut for on the Mummert baffle?
I don't have an original that I can steal the baffle from, but I can certainly bend something similar. And then a couple of screws and spot welds will work I reckon. Thanks all, I'll post a photo when done.
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By charliemccraney - 2 Years Ago
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A factory breather pipe or pcv adapter attaches via that nut. You can see a similar item on the factory cover baffle in Ted's picture - that one is spot welded.
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By Kingfisher - 2 Years Ago
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I bought a PCV on ebay that fitted perfectly. It's almost like ACE designed their product to suit.
https://order.ebay.com.au/ord/show?itemId=403582260806&transactionId=1151754649027&mkpid=0&emsid=e11401.m1842.l5919&mkcid=7&ch=osgood&euid=d1ae85d206cd400084961a67e1356152&bu=43765525669&exe=0&ext=0&osub=-1~1&crd=20230513193326&segname=11401#/
I then bent a piece of stainless roughly similar to the original and secured the bolts with some RTV. It's a bit rough to look at, but should work I guess.
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By charliemccraney - 2 Years Ago
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That looks like a pcv valve for my '88 Firebird.
Ace probably designed it to work with the stock parts, which so happens to be sized such that a pcv grommet does work.
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By 55blacktie - 2 Years Ago
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Kingfisher, do you have a part# for the pcv valve? I hope there is some space between the bottom of the valve and the baffle.
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By Kingfisher - 2 Years Ago
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The pcv sits almost flush with the bottom of the cover so there is about 1/2 inch between pcv and the baffle. 
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By 55blacktie - 2 Years Ago
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Let us know how it idles with that pcv valve. Maybe I'm wrong, but there's more to consider than size when it comes to pcv valves. The wrong pcv could cause vacuum issues that can affect idle quality. Hopefully, Ted has a recommendation.
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By miker - 2 Years Ago
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IIRC, DryLakesRacer had a post on measuring vacuum at the oil fill tube as part of PVC installation. And Greenbird56 had a post some years ago about fitting a restriction in the hose. Maybe those will surface again. They could also have been on another site, the Barn or the HAMB.
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By DryLakesRacer - 2 Years Ago
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If the oil filler tube or a breather in hole in a valve cover will not hold a piece of paper, I use a corner off of a blue paper shop towel, it probably not enough or you have another vacuum leak. Even you newer car engine should do this. Years ago I read an engineering report pertaining to PVC systems designed in the early 60’s that the vacuum on the crankcase should be between 1 and 3 inches of vacuum.
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By Kingfisher - 2 Years Ago
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Well I'm pleased to report that it idles and accelerates well with just very light suction on the filler tube with a piece of paper. I'm extra pleased that it actually starts!! considering that I've just this morning completed a total rewire. The pcv was a welcome distraction when I got sick of laying on my back working under the dash.
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By Ted - 2 Years Ago
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55blacktie (6/1/2023)
..... The wrong pcv could cause vacuum issues that can affect idle quality. Hopefully, Ted has a recommendation.
As a general rule, just pick out a PCV valve that’s used in a similar cubic inch engine. For the Y, PCV valves used in the 289/302 SBF engines will get the job done. I use the Microgard PCV 2322 in most Y applications. Here’s a link to a past thread giving some more detail.
http://forums.y-blocksforever.com/FindPost162636.aspx
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By 55blacktie - 2 Years Ago
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I am wondering if just attaching a flat piece of metal while leaving the sides open will work just as well?
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By Ted - 2 Years Ago
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55blacktie (6/2/2023)
I am wondering if just attaching a flat piece of metal while leaving the sides open will work just as well?
Any baffle that will prevent a direct flow of oil to the PCV valve will be adequate. Many of the aftermarket valve covers for all makes of engines did nothing more than a flat plate under the valve and/or oil fill cap to stop any oil from reaching those openings. My ’55 Customline received it’s PCV valve in 1989 and it’s nothing but a hole drilled in the original valley cover with a grommet installed to hold the PCV valve. No baffle and no oil consumption so if the valve is in a location that does not get a spray of oil, then no baffle is required.
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By charliemccraney - 2 Years Ago
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I use baffled grommets
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By 55blacktie - 2 Years Ago
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Thanks! That simplifies things. I just want to make sure that once done, it won't have to be addressed again.
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By MoonShadow - 2 Years Ago
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Next time you are under the dash just pull the front seat out. 4 bolts and its out of the way.
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By Kingfisher - 2 Years Ago
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Next time you are under the dash just pull the front seat out. 4 bolts and its out of the way.
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By 2721955meteor - 2 Years Ago
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pct valves. my approach is remove innards of pcv,run a hose to air cleaner inside the air cleaners no vacume is lost at carb. the oil filler cover has a small vacume. only time I had blow by showing was when I had to much advance at idel. this works great for me as running a newer Holley 4v 680cfm.i set my low idel like ted send using the idel screws on the primary.s use the fittings at throttle plate is 2 on the newer Holley. I use manifold vacume for power brakes, and vacume wipers
only negative is fuel hear in bc for the summer badger the thought that ethenall is going to save the world. no one in canada speaks out that fuel consumption goes up,a
with the bad fuel,aswell engine keeps running when ion. turned off.
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By 55blacktie - 2 Years Ago
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The Microgard pcv 2322 fits the Ace valley cover. Thanks, Ted.
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