just a question, I need a small pcv valve, with an outside diamter that's like 21/32 or smaller.. possibly with a 90* on it... Trying to fit it in a tube, and most likely seal it with an o-ring... Or if there's a smaller threaded valve that might work too... Any ideas?
Just a little FYI: PCV valves are calibrated for particular engine vacuum which is why there are so many different kinds around. They are designed to open during cruising and to close at idle and wide throttle. Using a badly mismatched PCV valve can be equal to using none at all.
Try mid 60's slant 6 PCV valve. It's 90 degree. Use a grommet appropriately sized and that will work.
Yes you want to size it for the engine CIs and not the external size. As Mike says they actually flow less at high vacuums (idle) than they do at the lower vacuums. (under a load)
You'll want one like these...a mid '60's Vette... http://www.jalopyjournal.com/forum/showthread.php?t=159551
If Im correct that is an equvelant of a Fram PF1 and if it is, it is designed to screw into the carburator base. And if it is, the the flow is backwards through your pcv valve. Not good.
Fram pcv valves start with "FV" as a prefix. "PF" is an A/C Delco oil filter prefix. The early, screw-in pcv valve was in Fram, I believe, an FV233, if memory serves. As far as too big or small the flow...who gives a rat's ass? Installing a pcv backwards is a valid concern, however. The one-way flow check valve could save your motor from grenading, however unlikely the conditions needed to do so.
No worries...It took me ten years to finally remember my wedding anniversary.... All my brain cells got used up memorizing damned part numbers from 35 years ago!!
That being the case, 32rules is 100% correct in saying that the valve would be useless mounted the way the article says.
If the article referred to is the one that shows the pcv screwed into the intake, I don't see a problem with it. It's tapped into the part of the manifold that covers the valley. With the other end plumbed into the carb base, it would pull fumes from there just as if it was screwed into the filler tube in it's original application. Bob
No need to freeze going out to the garage. The answer is right here thanks to the HAMB. Looks like oil fill tube to me. http://www.jalopyjournal.com/forum/showthread.php?t=92105 Bob
If the threaded end is designed to go into the oil fill tube, the hose end would go to the vacuum source. If you put the threaded end into the vacuum source, the one-way check valve would be backwards. The "Positive" in Positive Crankcase Ventilation means that in case the oil/fuel vapors should ignite, the flame would be stopped by the one-way valve, thus preventing your engine from grenading.
I didn't design it. All I did was provide evidence that it in the original application it went in the oil filler tube, and not the carb base. If it won't work that way, take it up with Chevrolet. Bob
Relax. I'm not saying you're wrong. It's important which direction the vapor flows. The concensus seems to be that the threaded end of the Fram FV100 goes towards the "collection" of crankcase vapor. There is another, threaded PCV used on early GMs in which the threaded portion went into the manifold (vacuum source). I seem to remember it as an FV233.
Look one up for a 62-64 Galaxie with a 352. It screws into the intake like the one in that article. One of the old Ford numbers was EV1 and the Borg-Warner number is PCV255.
I looked it up on rockauto.com and it list the PCV valve as being a Fram FV100, which is the same one that Chevrolet uses in the '66-'67 327 oil filler tube. Bob
Check out one from a 90's Dodge 3.0 liter V6, very small diameter, threaded on one end and some I have seen have a 45 degree bend in the hose end.
Are you sure you got the application right? Chevrolet used 2 different PCV valves in the same years with a threaded end. The FV100 screws into the Rochester 2bbl carb base on the 283s. The threads are on the vacuum source side. I use one and always check before I screw it in. I don't know the number of the 327 Corvette and the high HP engine PCV valves that screw into the oil fill tube. Same years, same manufacturer... different valves. You can't tell by looking at them in a box. I use the low tech approach and suck on each end. The side that lets you get air is the side that goes to the vacuum source. If it slams shut then that is the crankcase side to prevent a backfire from igniting the gasses in the crankcase.
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