Classic/Antique Car Repair: radio frequency interference shield, radio frequency interference, interference shield


Question
If I may ask you what 1970 chevrolet cars have RFI shields, if by chance have access to a 1970 chevrolet chassis service manual, in the distributor section it shows a picture of them.  It 2 pieces goes under the rotor, over the points and condensor, [betcha these rfi's ended up in the garbage can]. I personally saw one.
I don't think it is a Vette only item, because they had there own unique shields.
I have googled rfi's and auto zone tells how to remove them to change adjust points.
Could the rfi be unique to the am/fm radio and or the factory 8 tack player.   Thanks for you time  Frank

Answer
According to my reference books, only the Corvettes with big block engines have them (I'm using the labor chart which adds time to the flat rate labor estimates for those with the anti-rfi shields).  I'm not sure that is the last word on the subject, though, because I have no other way to verify the information.  If you could find a parts book for your car, you could verify that easily - but I don't have a library of parts books for Chevrolets.

I happen to be an electronics engineer (long retired, of course), and I can tell you that only a fiberglass body would require such a shield - the grounded hood on steel body cars would be sufficient to avoid bothering other electronic devices, as long as the hood grounding provision is intact.

The 8 track tape players wouldn't be that sensitive, nor would FM radios - in fact the serious interference problems were with AM radios, not FM.

Sorry I can't be more positive.

Dick