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My mechanic says it isn't really necessary. More for looks. Is that so? He said it was mounted with intake bolts and was interfering with keeping bolts tight on intake. He suggested leaving it off when installing petronics 1181 module. Oh, and any feed back on the module as well. Thanks
are you trying to stay original or doesn't matter?
if it doesn't matter, get a mini starter off a C4... dirt cheap and no more heat soak
the main problem of the factory starters are they are HUGE... and are close to exhaust primaries... so they pick up even more heat... you get a mini from a C4 and BAM... problem solved and you have WAY more power to start your engine with.
Your mechanic is giving you a line of because he's tired of screwing with the shielding. Yes, it was needed...and still is...if you still have the original Delco radio in your car. That unit was sensitive to ignition generated EMF spikes which make pop/crack noises in the sound produced. Modern radios have better rejection of those spurious signals.
I keep that stuff on because I still have the Delco unit....and because I like it. I do things with my car that I like...not because of what some mechanic wants.
AM radios picked up interference from the ignition wires back in the day, hence the 'Radio Interference Kit' or the chrome shielding. It is a real PITA especially on an A/C car, but it sure looks kool and not necessary anymore unless the OEM radio is in place. Pertronics are good ignition systems, find out if you need to change your ignition coil to one that is suitable for the Pertronis ignition. An internal resistant coil is wrong for electronic pick-up ignition. T
Last edited by terrys6t8roadster; Aug 15, 2018 at 01:48 AM.
My mechanic says it isn't really necessary. More for looks. Is that so? He said it was mounted with intake bolts and was interfering with keeping bolts tight on intake. He suggested leaving it off when installing petronics 1181 module. Oh, and any feed back on the module as well. Thanks
Mine's been in a box since the day I bought it. Radio works OK but I don't use it much and chances are if I did I'd want the shielding on.
Apart from the radio there is one thing about the passenger side bracket for the chrome breadbox - the vacuum advance can has to be behind it (closer to the firewall.) or it doesn't fit right. Gets a little confusing when you have to relocate the plug wires to accommodate that. I was wondering if your mechanic is looking at that and either didn't know or didn't want to deal with it.
Even in early 69 you did have to relocate the plug wires in order to get the right timing and clear the vac advance. Also the dist. box, top, wire channels and boomarang pieces are all a pain in the butt as well as the spark plug shields with the tiny twist screws. A great look though once all on. I could see how mechanics would have this stuff just getting in the way of what had to be done. When I worked on my 65 all of that stuff was the first to be removed.
If they were needed why didnt other GM cars have them?
LIke the look but a pita to deal with. Surprised nones come up with a look alike thats easier to put on. A good metal guy could fab one up in an afternoon
The 2 rear intake bolts, use threaded studs where the assy could slip on?
If they were needed why didnt other GM cars have them?
LIke the look but a pita to deal with. Surprised nones come up with a look alike thats easier to put on. A good metal guy could fab one up in an afternoon
The 2 rear intake bolts, use threaded studs where the assy could slip on?
I wonder if it had to do with a steel firewall vs a fibreglass one?
I wonder if it had to do with a steel firewall vs a fibreglass one?
correct, fiberglass doesnt act as a shield like a negatively charged steel one does, plus the rest of the car being fiberglass doesnt really lend well to containing EMF in the engine bay
Correct-- fiberglass doesn't shield.. back in the day- GM had to add ground wires from the hood to the firewall on several steel cars/trucks to solve RFI problems - as the hood was isolated from the rest of the body.
It's RFI (Radio Frequency Interference) that the spark plug & wires were emitting and really only effects AM. FM (Frequency modulation versus Amplitude modulation) uses a much better way of carrying the audio signal and not really affected by RFI. Resistor plugs and new technology in the wires solves most of the interference anyway.
I just read this and have to laugh.. The only question at this point concerning this is do you listen to am radio in the car? If not the mechanic is correct. So many purists out there is seems that believe its needed just because it was there from the factory that would love to see your mechanic strung up... lol. Its really up to you and if you feel its an important aspect of the car to keep it on at this point... if it were an all original show car I would keep it.
I dont have it on my 74 and since I put the HEI in the rusty mess that came in a box with my car wont fit anyway... no issues but I have a cheap "retro" radio with FM...
Last edited by augiedoggy; Aug 16, 2018 at 10:51 AM.
On my 1980 I took off its shield (a little different from same principle) the first time I changed wires, about 10 years old, and never put it back. Radio was fine.
On my cousin's 1974 he had it off and went through a car wash. Engine missed and stumbled for several miles until it dried out. Now, don't fault us for taking a classic vette through a car wash. It was 1977 and we were 18 years old so it wasn't a classic. Now I guess it is a classic if it still exists and I guess my cousin and I are too.
Last edited by vince vette 2; Aug 16, 2018 at 12:13 PM.
My 69 SBC got treated to a Holley Sniper fuel system upgrade, I took advantage of using the ECU to command the timing on the MSD distributor requiring the removal of the distributor to lock out the mechanical advance. So the OEM shielding was off during the test and tune of the new system. There was problems with the engine stalling, stumbling and hard starting. After numerous conversations Holley tech instructed me to run a 'data log' and e-mail it to them for review. Their finding was HFI. After numerous changes to the install not resolving the problem it struck me HFI and RFI are they the same. Reinstalled the OEM shielding and have been enjoying the fruits of my labor for the last 3 months with no problems. In my case I guess the shielding is necessary. T
Your mechanic is giving you a line of because he's tired of screwing with the shielding. Yes, it was needed...and still is...if you still have the original Delco radio in your car. That unit was sensitive to ignition generated EMF spikes which make pop/crack noises in the sound produced. Modern radios have better rejection of those spurious signals.I keep that stuff on because I still have the Delco unit....and because I like it. I do things with my car that I like...not because of what some mechanic wants.
Ignition shield - is it necessary?
because he's tired of screwing with the shielding. Yes, it was needed...and still is...if you still have the original Delco radio in your car. That unit was sensitive to ignition generated EMF spikes which make pop/crack noises in the sound produced. Modern radios have better rejection of those spurious signals.
