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. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

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.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

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.

The pcv sits almost flush with the bottom of the cover so there is about 1/2 inch between pcv and the baffle.

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. 

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.



Lawrenceville, GA

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.

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.



Lawrenceville, GA

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.

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.



Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire