[unruhjonny]

I have seen referance to an RFI (Radio Frequency Interferance?) shield which was installed from the factory on pooints distributors;
I have understood that they were generally thrown out at the first service appointment.

Does anyone run one?

Can anyone shed light into one of the small items that I have read of, but never actually seen before?

Do they actually serve any legitimate purpose?

Does anyone here swear by them?

And just for the record, I am probably in an extreme minority here, in that I legitimately run points in my OE distributor, in my Firebird...

[george kujanski]

Check some Corvette manuals....with the plastic body, any underhood EMI (electro-magnetic interference) which is normally shielded by metal hoods, cowls, etc. gets out all over the place, so the vette may have the shields.

I suspect it is a metal can that fits over the points; I know the plug wires in those days ran inside a metal tube..

George

[geeteeohguy]

I've seen several of them in the past, when tuning up GM cars in the late '70's thru the early '90's. They are a two piece assembly that overlap in the middle. Each half is held to the dist. plate with one screw. I always put them back on the car, but most cars didn't have them. They were on all types of pre '75 GM cars, not just Corvettes.

[unruhjonny]

Originally Posted by geeteeohguy

I've seen several of them in the past, when tuning up GM cars in the late '70's thru the early '90's. They are a two piece assembly that overlap in the middle. Each half is held to the dist. plate with one screw. I always put them back on the car, but most cars didn't have them. They were on all types of pre '75 GM cars, not just Corvettes.

I think I have read that they were often removed because you couldn't set dwell with them in place - does that sound about right?

[geeteeohguy]

If I recall, one of the halves had a cut-out to allow access to the allen screw on the points. They were thrown out because the techs were lazy. I used a screw-starter to start the screws, since they had to be taken all the way out and were kind of awkward. I figured if the car had been in service for 10-20 years with the shield in place, far be it for me to throw out the shield when I got ahold of it. I think I have one somewhere I got from a junked car long ago....was going to install it but never did. My radios sound fine..

[unruhjonny]

Originally Posted by geeteeohguy

If I recall, one of the halves had a cut-out to allow access to the allen screw on the points. They were thrown out because the techs were lazy. I used a screw-starter to start the screws, since they had to be taken all the way out and were kind of awkward. I figured if the car had been in service for 10-20 years with the shield in place, far be it for me to throw out the shield when I got ahold of it. I think I have one somewhere I got from a junked car long ago....was going to install it but never did. My radios sound fine..

If you found it, I'd buy that off you.

I might even be driving your way in April en route to my Mom's place, if you would rather not mail.. lol

[Schurkey]

I remember a stamped-sheetmetal cover that fit over the breaker-plate. It was made in two pieces, held to the breaker plate with a couple of screws. I'm thinking that cars with the windshield antenna got them, on engine families with the distributor in the rear.

[MescaBug]

That. There is a cutout to adjust the points.

[BruceWilkie]

More often than not actual radio noise picking up ignition signals was actually antenna related. Poor antenna ground or the antenna "trim" adjustment inside the radio. More common to pickup noise with non originally installed antenna due to cable quality and length differences. Not all radios are easily adjusted. Trim pot locations vary. Some were behind a tuning or volume knob others near antenna connection. Gettin it tweaked in made a big difference in noise and capability of pulling in far away signals.
Todays digital stuff seems to tune itself to a degree but a poor antenna ground or inferior cable can still cause noise and weak signal issues...more notable when you are on AM band.
Todays efi cars use a lot of various rfi/emi control methods to keep computer and injectors etc. from hiccups.

[BruceWilkie]

To the OP....

And just for the record, I am probably in an extreme minority here, in that I legitimately run points in my OE distributor, in my Firebird...

Nothing wrong with stock points...Stock points work fine when maintained... when they arent maintained is whats "wrong" with them.

Points can really last and be near maintenance free if you use them to trigger a CD box... Only need to open enough to switch the cd circuit(so can be set close to tolerate much higher rpm without need for heavy tension to avoid point bounce). The low power across them when used as a signal keeps contacts in great shape and the condensor isnt required. Keeping a std coil and condensor in glove box can get you up n goin fast should the cd box/coil fail. I triggered my Accel box with points for years on same set of Delco std points and rpms as high as 7400 without issues. Sold the box but new build I'll do the same setup with same 59 iron body distributor and 14 year old points.(till I go distributorless EFI)

[unruhjonny]

Originally Posted by MescaBug

That. There is a cutout to adjust the points.

THAT IS SO COOL!!!

I have seen some small drawings of these parts - but this is the first time I've seen the actual parts!

[67drake]

I haven't seen one of those in years!
I remember changing points on either my 73' GP or my 71' Impala and that was the last time I've run into a car with the RFI covers.
As somebody stated above I don't think FM radio is the big issue with RFI. Remember, back in the early 70's when these cars were made,more people listened to AM radio than FM. AM was more susceptible to ignition interference than FM.
BTW,I still run a points distributor too.

[lust4speed]

So weird. I never knew that shields came on anything but Vette's - that's the only place I've ever seen them. This must be the bottom section and there's a top cap also?

[Schurkey]

Originally Posted by lust4speed

So weird. I never knew that shields came on anything but Vette's - that's the only place I've ever seen them. This must be the bottom section and there's a top cap also?

The breaker plate acts as the bottom section, this two-piece unit goes over the top of the points, under the rotor.

As I said, I think these were made necessary due to the windshield antenna.

[geeteeohguy]

I can't remember if the ones I dealt with were on cars with windshield antennas or not. It's been a long time, over 20 years.

[MescaBug]

I see them quite often on eBay. Last one I saw sold for 25$. They are cheap.

[unruhjonny]

Originally Posted by MescaBug

I see them quite often on eBay. Last one I saw sold for 25$. They are cheap.

Really?!

I have never observed them... weird.

[MescaBug]

Yesterday. I think its the 4th I've seen this year.

http://www.ebay.com/itm/Delco-RFI-Po...vip=true&rt=nc

[unruhjonny]

Originally Posted by MescaBug

Yesterday. I think its the 4th I've seen this year.

http://www.ebay.com/itm/Delco-RFI-Po...vip=true&rt=nc

cool!

after my last post, I did a couple searches and found nothing...

[MescaBug]

Keep looking! I've got a few saved searches on eBay. I ran those searches once in a while.

Now that I think about it, I should have let you know there was one for sale.. But I havent been on the forum lately...