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Probably a dumb question, but what is the purpose of the plastic/grounded hat that sits on top of the distributor on my '84 resuscitation project? EMI suppression? The thing is annoying to deal with.
How do you all feel about the plug wire retainer ring? Also annoying 🤔.
the entire underside is foil coated with a ground strap that attaches to the top plate of the intake. More than appearance I'd say but hell if I know... Knowing GM, could just be attached to the intake so you don't lose/misplace it.
So foil lined and grounded. (?) Am back to noise suppression. In the 1960's, where I lived there was a demand for Corvette distributor shields as they'd get left off, lost, stolen. Made enough difference for radio to be quite noticeable. Old ones were metal and shiney, too.
So foil lined and grounded. (?) Am back to noise suppression. In the 1960's, where I lived there was a demand for Corvette distributor shields as they'd get left off, lost, stolen. Made enough difference for radio to be quite noticeable. Old ones were metal and shiney, too.
It's the 80s. Had to be plastic lol.
If you look at the picture you can see the ground strap next to the distributor coming from the "hat" it is also not connected.
the entire underside is foil coated with a ground strap that attaches to the top plate of the intake. More than appearance I'd say but hell if I know... Knowing GM, could just be attached to the intake so you don't lose/misplace it.
I always thought it was designed to enhance appearance and doubled as an ignition shield. In the GM parts and Illustration catalogs it's listed as "SHIELD, DISTR RFI"(GM part # 14067303). I like the look of it installed (cleaner) as opposed to being missing. I don't find it annoying, most of the time it's untouched, just look at the "latch/hook" design on it and you will quickly figure out how it attaches and how to easily remove it! I'll throw my hat in the ring also, if you don't want your's, I'd love to have a spare👍
Edit: as far as the f-bodies not having them, that made me think of ignition shielding in general, and really I can only think of Corvettes having it (C1,C2, C3, C4), my only conclusion is what the bodies are made of. Perhaps fiberglass/SMC ia prone to a lot of static electricity or something along those lines!?
Last edited by '78CorvetteS.A.; Apr 12, 2022 at 05:52 AM.
F-bodies not having them, that made me think of ignition shielding in general, and really I can only think of Corvettes having it (C1,C2, C3, C4), my only conclusion is what the bodies are made of. Perhaps fiberglass/SMC ia prone to a lot of static electricity or something along those lines!?
That's a good point. You're right that you only see 'em on Y body cars.
From an RF point of view, if the shielding is for noise suppression then the attenuation is only above the plastic hat. The RFI and EMI would still be present in DC cables and radio's in the horizontal plane. I would ditch the hat without concern. Probably trying to fix a concern in the early 80's that nobody cares about today. If it was a good solution then distributors would be shielded but that would likely cause spark to jump to ground prematurely if to close. Last, if you do get any noise in radio or other electronics a ferrite ring core noise suppressor is cheap and easy to add to any cable.
From an RF point of view, if the shielding is for noise suppression then the attenuation is only above the plastic hat. The RFI and EMI would still be present in DC cables and radio's in the horizontal plane. I would ditch the hat without concern. Probably trying to fix a concern in the early 80's that nobody cares about today. If it was a good solution then distributors would be shielded but that would likely cause spark to jump to ground prematurely if to close. Last, if you do get any noise in radio or other electronics a ferrite ring core noise suppressor is cheap and easy to add to any cable.
I had a long thought about this statement. And the only thing that popped in my mind was that maybe it was for the CB? It's really the only other quirky 80s thing I could think of aside from the usual suspects....
I had a long thought about this statement. And the only thing that popped in my mind was that maybe it was for the CB? It's really the only other quirky 80s thing I could think of aside from the usual suspects....
That's a great thought! I overlooked that possibility!👍
On a side note of my previous post (directed to no one in particular) I wasn't arguing one way or the other if it's effective or not, only mentioned how it's actually listed in the parts catalog. That being said, I don't think it does much, aesthetically speaking I feel it looks better on than when missing....as mentioned, it is foil lined and strapped/grounded to the engine....perhaps a ground path for a faulty plug boot or coil, something to do with the '84 only gauges, IDK! I do know GM engineers wanted it and GM paid to produce and install it on every '84 built. Although it's not as "integrated" as the TPI distributor cover, to me it's as noticeable/incomplete when missing on the L83 or L98👍
Distributor "hat"
