Question: Up market plugs

[English Guy]

Hi, I need to fit new plugs soon and was wondering if the platinum type lives up to the hype. Thanks for any info on this .

 

[boomdriver]

Hi, I need to fit new plugs soon and was wondering if the platinum type lives up to the hype. Thanks for any info on this .

I've tried several types of platinum gimmick plugs and they did nothing at all for the HEI ignition. The GM system really likes its delco parts. I use the best grade Delco plug thats the same spec as the original.
The Bosch +4 actually fouled.

Most of those platinum plugs are made for the ricers in the world. They produce a smaller hotter spark that works fine in the smaller hi compression motor thats probably turbo'd.
The SBC V-8 gets better combustion off the bigger electrodes on the fatter Delco plugs. the system is plenty hot, its more about the size of the spark since we have heads that are NOT hemispherical, the spark has to initiate the ignition/combustion and follow a "flame-path" to get the proper burn.

After 24 yrs of C4's...I've learned that the ONLY ingition parts that I am assured of working well in the Corvette are all Delco. Wires, plugs modules etc..JMO

 

[English Guy]

Thanks for gen Boom. I'm glad I did'nt sucked in by the marketing bs, I'll stick with the delco's & save some £££'s too!
Btw who/what is a ricer, is it the same as a mincer?

 

[Dad]

Interesting, for the most part I agree but wonder if today's gasoline has anything to do with plug life in the older engines. I just changed a set of Iridium plugs from a 3.8 Pontiac and was surprised at how good they looked. The miles were quick, 113,000, less than 3 years so that may account for some of the way they looked. On the other hand I pulled 3 from my '72, which has the standard AC plugs, and they look like they will need changed soon. That driving is just the opposite of the above mentioned Pontiac, slow and seldom.

I did the same thing with my Cadillac at 118,000 and put them back in, they were Platinum. GM now uses Iridium and I've pulled them on the C6 and put them back after trying NGK, bad mileage but ran just as good. Not sure the spark size from the electrode configuration is a detriment to the older engines or not.

My take on the Platinum and/or the Iridium is that they do what they were intended to do, run 100K miles, but at a higher initial cost than the standard plug of yesteryear for a much longer time/miles considering today's fuel.

 

[boomdriver]

Interesting, for the most part I agree but wonder if today's gasoline has anything to do with plug life in the older engines. I just changed a set of Iridium plugs from a 3.8 Pontiac and was surprised at how good they looked. The miles were quick, 113,000, less than 3 years so that may account for some of the way they looked. On the other hand I pulled 3 from my '72, which has the standard AC plugs, and they look like they will need changed soon. That driving is just the opposite of the above mentioned Pontiac, slow and seldom.

I did the same thing with my Cadillac at 118,000 and put them back in, they were Platinum. GM now uses Iridium and I've pulled them on the C6 and put them back after trying NGK, bad mileage but ran just as good. Not sure the spark size from the electrode configuration is a detriment to the older engines or not.

My take on the Platinum and/or the Iridium is that they do what they were intended to do, run 100K miles, but at a higher initial cost than the standard plug of yesteryear for a much longer time/miles considering today's fuel.

From what I've experienced the platinums and iridiums and the like seem to benefit the smaller displacement, higher rev engines the most...the ricers. Japanese can-cars.

Those all run very hot, very lean and most are build with forged internals to handle the extra stress. Our SBC motors are not made to spin 6000 running thru the gears. Some OHC engines don;t even redline untill 7500...
I think our older EFI might be part of it as well. Its not as efficient as multiport or sequencial. So there is more raw fuel left sitting to wet plugs as they cycle.
I remember expecting some difference and was dissappointed when it seemed to be a flatter feeling engine. It definately regained some pep when I put the Delco back in.

PS...for English..

Ricer = small annoying Japanese "not so fast but sound really furious" cars...you know, those guys with the trash can welded to the exhaust that follows the car......

 

[Dad]

Not sure what you're saying, all the plugs I'm talking about were/are AC Delco that came with the new Cadillac, Pontiac, and Corvette (3). The Cadillac was a '92 and had Platinum and all the new cars I have had since then have been AC Delco Platinum or Iridium. As far as I know none of them were Japanese engines.

As for the trick tip plugs like the "V", "Split Fire", and the "Ring of Fire" type hype I've never tried them except the NGK which was gone after 1400 miles.

I will say if I have to remove and replace the shielding on the '64 to replace the plugs they would be Iridium, if AC had one. Can't think of a job I like less than that.

By the way I hate AC Delco's new numbering system, what the hell is a 41993 plug? Yes, I know what Platinum plug it is, just don't like the numbering system they are now using.:confused

 

[93Rubie]

FYI, platinum tipped plugs are almost universally used by the OEM and come in just about every new car. If I remember correctly starting in 93 Corvettes have them as factory.

 

[Dad]

Actually they started using the Platinum plugs before the 1993 Corvette and are now using Iradium nearly across the board at GM. There was some issues with the Platinum as the plug used in my '92 Cadillac has been changed 3 times sofar.