I just thought is was a good idea, to keep the road dirt coming though the fan to go directly on the K&N filter. 

Located in Harford County Maryland 

Yes, there was a reason for what is being called a shield here. It was a Deflector, intended to direct ventilation air into the engine.  For some reason it was deleted on later engines & keeping the oil  cap " filter clean"  apparently wasn't really emphasized, leading to many sludged up engines.
 


Paul

Those were pretty much a holdover from the flathead days. No rhyme or reason to have the shield that I can guess.





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

BTW:  Just noting an odd quirk:  If I remember correctly, the earlier OEM models had a shield, but when it was done away with (deemed unnecessary and another way to save of few pennies per car in production costs?), the stamped directional orientation instructions in the top cover remained on the stock cap, resulting in much puzzlement.

6 VOLTS/POS. GRD. NW INDIANA

I have the one from K&N. I like it.  Just have to measure the tube to get the right diameter. I like the deflector shield built on to it. 
Especially when the fan clutch locks up.  

Located in Harford County Maryland 

Mummert lists a few different caps on his web site in conjunction with his aluminum covers.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Nice.  Thanks for the info.  I put in an order for one from Dennis Carpenter...and good call on the FE, Ted.  I had a MAJOR brain fart and was about to "SUBMIT" my order for one for a 1958-1965 (?) Thunderbird when it dawned on me that Ford SLOWLY killed the Y block starting with the T Bird and that this would have been an FE.  I was thinking that my engine was from a '59 Fairlane.  I knew better.  I guess it wouldn't have mattered anyway.  

Many years ago I purchased the reproduction breather cap for T-birds because it has a dense foam filtering media inside similar to what many small engine air filter are made of. By adding one drop of motor oil in each hole helps collect and hold airborn dust.  It gets cleaned in mineral spirits every yeart and reused. The fit on the oil filler tube is very good, like, better than most.  Judging by the dirt that comes out of this cap I'd say it works great and  no need for a closed cap piped to the engine air filter housing.  Just my 2cents............
   



64F100 57FAIRLANE500

Theoretically, the more effective the filtration, the better it is for engine life, though if overly restrictive it might somehow effect PCV function (?).  The spring-mount caps (like orig.) allow too much unfiltered air to pass around the tube-to-cap fit, though if too tight it can make adding oil rather troublesome.

6 VOLTS/POS. GRD. NW INDIANA

Have any of you guys used a K&N crankcase filter for your filler cap? I've seen them used on our y-block engines but never actually heard if they are useful in this application? Pricey, I know by comparison.

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