DLRacer;  Re your mention of insufficient filtering thru oil filler caps.  Ford, however used that system for the draft tube crankcase venting.  Apparently they thought the original caps filtered well enough. (?)  Early ones had an air scupper on them to assist air flow.  Now, the system was flawed in the end effect that many owners just used it as a filler cap & didn't keep the filter material clean. It was facing down when installed, unnoticed & seldom serviced.  A leading cause of crankcase sludge buildup.. And often original very dirty caps were discarded in favour of cheaper & smaller ones.  (cute chrome ones were popular) My recent PCV installation uses a large Ford authorized cap (Autolite?) that appears to have decent filter material in it.. I won't be driving it in dirty conditions, so I'll just stick with it..  About the smell you refer to after the engine is shutdown. Is that crankcase odor, or are or are you smelling gas?. So far, I haven't noticed any fumes coming from the crankcase when shutdown. (by chance the PC valve is original to a smaller V-6 engine). Does that make a difference? I don't know?  Of course the system isn't perfect, in terms of sealing all fumes, because later original equiptment carburetors used closed sytems with a charcoal fume canister etc..            


Paul

A further thought or questions on a PCV after market setup;  Smell has been mentioned here, apparently after the engine is shut off. In my case there has been no what I'll call crankcase smell or odour. However, my carb is a Ford Autolite 4 Bbl, and I've noted that when the engine is warm or the area is warm, there is some faint Gas odour at times.  If I have it right, the carb appears to have 6 vents !.  4 verticle tube vents inside the air cleaner area & two others, one each on the top of the float Bowls.. The front bowl vent is about 5/32" in diameter.  If I'm right, why so many vents allowing fuel to just evaporate away?..             


Paul

JFYI -

This is how FORD designed the 4V install. It has an oil baffle and vapor cooling tube.




Placing the valve @ the earlier road draft tube opening will draw vapors unless a fabricated mesh screen is inserted withing the baffle.

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why so many vents allowing fuel to just evaporate away?

The reason for EVAP being introduced in 1970's.

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Thanks for the explanation & illistrations.. However, I realize that drawing oil up into the PCV is not desired & that's why I left the original sheet metal oil deflector on the underside of the valley pan,( with the original lower attachment hole plugged) similar to what Ted Eaton has done. (I originally drilled small drain holes there, but it became apparent that wasn't a good idea)  But, I'm still a little confused, isn't it intended that the PCV system is to draw crankcase vapors back thru to be re burned in the combustion chamber?  On the other hand, I realize that's a somewhat different issue than the Gas evaporation issue, which seems to be quite noticeable, particularly if the car is parked in warm weather without the air cleamer housing & filter installed, which possibly dampens the venting of the 4 inner vent tubes to some extent..      


Paul

But, I'm still a little confused, isn't it intended that the PCV system is to draw crankcase vapors back thru to be re burned in the combustion chamber? 

It is designed to burn crankcase fumes and create a partial vacuum in the crankcase but not to ingest large amounts of suspended oil vapors. There has to be a baffling device before the valve and/or the engine has excessive blow-by. Excessive fumes will also defeat the valve operation as it will become partially blocked and the valve pintel will not function correctly..

Pull your dipstick and take a whiff. Do you smell gasoline? If you smell gasoline, she is running too rich or has carb leakage (or inoperative CCV).. How about the exterior of the carb? ESSO gas used to use a red dye and you could tell by the carb being pinkish when you pulled the ACL.

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PF Arcand, If your cleaning the PCV system intake air, which is the oil filler cap for us, I have no doubt that it helps that air entering the combustion part of the engine thru the PC Valve will be fine. My suggestion is still today the air entering the system is coming from the air filter holder even in my 2018 Ford F-150 Coyote engine. As for smell, anytime the engine is shut off depending on it's mileage there will be vapors and some more than others; since my car is not equiped with a PCV system and still has the road draft tube upon engine shut down there is always an odor. I decided to try and minimize it by adding a line into the air filter system of my Y oil fill tube and the odor is now gone for the most part.

I have added oil separators (aka catch cans) to both of the cars we have for daily transportation and they do as intended keeping oil out of the intake runners. The one on my F-150 is designed by Ford Performance and always has oil in it when checked. My wife's Honda Civic has a Moroso and it too has oil in its reservoir. If I had a PCV system on my 56 it would have one also. There are many pros and cons about them and can be easily researched on you tube so an opinion by folks can be made..Personally any direct injection engine really needs one of these. 

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