overpriced exotic metal spark plugs that underperform!!

[Jetronic]

Yeah, I kind of forgot that, and missed the x10^-5 note on the graph I was looking at, but I was thinking what happens in the centre electrode?
So 25000V is needed to jump the gap, but to get there, the charge went through the plug which is say 5000 ohms resistance, so isn't it 5 amps of current in the centre electrode?
I dunno? I think I need to do some more reading!

No you need to add all the resistance together. With the plug tip grounded to the electrode it would be 5 kOhm + the coil an wire resistance. The coil has a significant resistance by itself

 

[ARCOgraphite]

Copper is the best conductor. The better platinum/iridiums are mostly for longer life not performance so there is some truth in that teeny tiny bit of possible additional power with a traditional copper plug. ... .

The Cu core is for HEAT conductivity. Boy has got to hit the books one high-tension transmission and electro-static dissipation.

Jeepers, plug wires used to be glass fiber and cotton dusted with carbon before COP.

 

[OVERKILL]

Nah, copper is the term for that plug; I didn't name it; go bark up someone else tree about that.

And hamburgers are beef patties. We'd be having the same discussion if you were claiming ham is a better protein by using examples of hamburgers. Words matter.

Per NGK:

BTW, also NGK's website:

Not surprisingly, as has been mentioned in this thread ad nauseam, both have a 98% copper core.

And it's a nickel alloy, not a straight nickel tip on the copper core. Don't forget as you're playing for semantics here.

Yes, an alloy using materials that are even less conductive than nickel. Sandvik 522, which is however, 94-95% nickel.

It was just more efficient/conducted better for that test by the resulting extra, however minuscule, hp/trq whatever it was. Sorry deleted your fart comment by accident, although I do believe you are trying to discredit someone else's data.

That's your claim, so again, how do you square that with the fact that it is not in fact a better conductor than iridium? Also, my point about farting near the dyno, while crude, is factual. There are error bars on this stuff for a reason, as I mentioned. Somebody could smoke meth near the dyno and if the results improve, do we credit meth?

This old Motortrend article mentions some things that can change the results for example:
https://www.motortrend.com/how-to/hrdp-0405-chassis-dyno-guide/

There are many ways to produce inaccurate results. Some methods are malicious; some are from poor test procedures. We've discussed how myriad environmental factors can affect the results. Obtaining consistent, accurate results in the first order requires controlling these variables to the extent possible. "If nothing is controlled, it's all bull," says Jeff Burt. "The more things are controlled, the more accurate the test will be." At a minimum, the facility should accurately correct for atmospheric conditions, which is standard practice for engine dyno-testing.

Varying the tie-down method or tension from run to run can significantly alter the results. Other ways to skew results include changing tire pressure, testing the car when the engine is very hot or cold, lying to the software about estimated wheel slip, hacking the software in general, moving the external dyno cooling fans closer or farther from the air inlet, and placing the temperature sensor in unusually cold or hot air so it skews the SAE correction factor.

This article notes that overall repeatability was within 2% average variance for the dynos they tested:
https://dsportmag.com/the-tech/dyno-tech-guide-part-three-verdict-dyno-showcase/

So, let's say the engine dyno'd 400HP with the nickel plugs, 2% is 8HP. See what I'm getting at? There are all kinds of "dyno tests" where the results are within the error bars of the equipment but get trotted out as definitive proof.

And as far as iridium being able to handle higher temps, double ~ and last longer, that's about it.

It's the more conductive metal, I mentioned nothing about its added ability to last longer and handle higher temps, it's simply the more conductive and less resistive material.

However, I do believe the copper, wait... nickel plugs move heat away a little better than iridium. Could also be the reason the copper plug got the gain the others didn't.

Thermal conductivity of Nickel is 105 W/m K, Iridium is 153 (copper is 413, that's why the cores are copper). So no, iridium is the better thermal conductor. That said, the area of the tip of the plug with precious metal plugs is usually smaller, so there's more surface area with the nickel alloy electrode. Both are roughly the same diameter from that point up through the body of the plug however.

 

[johnmyster]

yes the resistance of the gap is measured in mega ohms.

It also changes. The resistance of the gap on your workbench is one thing. It's higher with a fresh gulp of air squeezed into the combustion chamber at 12:1. Then it's less once the air ionizes.

One time our truck would miss under load. Idled just fine. Pulled it into the shop and popped the hood. Put it in gear and stood on the brakes. Under a load the plug wires looked like a lightning show. Bad wires, but they only "leaked" under load, when the voltage required to imitate gap across the gap is higher.

 

[Jetronic]

It also changes. The resistance of the gap on your workbench is one thing. It's higher with a fresh gulp of air squeezed into the combustion chamber at 12:1. Then it's less once the air ionizes.

One time our truck would miss under load. Idled just fine. Pulled it into the shop and popped the hood. Put it in gear and stood on the brakes. Under a load the plug wires looked like a lightning show. Bad wires, but they only "leaked" under load, when the voltage required to imitate gap across the gap is higher.

I know but that's spark plugs 102

 

[CarlB]

And hamburgers are beef patties. We'd be having the same discussion if you were claiming ham is a better protein by using examples of hamburgers. Words matter.

Per NGK:
View attachment 244754

BTW, also NGK's website:
View attachment 244749
View attachment 244750

Not surprisingly, as has been mentioned in this thread ad nauseam, both have a 98% copper core.

Yes, an alloy using materials that are even less conductive than nickel. Sandvik 522, which is however, 94-95% nickel.
View attachment 244760

That's your claim, so again, how do you square that with the fact that it is not in fact a better conductor than iridium? Also, my point about farting near the dyno, while crude, is factual. There are error bars on this stuff for a reason, as I mentioned. Somebody could smoke meth near the dyno and if the results improve, do we credit meth?

This old Motortrend article mentions some things that can change the results for example:
https://www.motortrend.com/how-to/hrdp-0405-chassis-dyno-guide/


This article notes that overall repeatability was within 2% average variance for the dynos they tested:
https://dsportmag.com/the-tech/dyno-tech-guide-part-three-verdict-dyno-showcase/

So, let's say the engine dyno'd 400HP with the nickel plugs, 2% is 8HP. See what I'm getting at? There are all kinds of "dyno tests" where the results are within the error bars of the equipment but get trotted out as definitive proof.


It's the more conductive metal, I mentioned nothing about its added ability to last longer and handle higher temps, it's simply the more conductive and less resistive material.
View attachment 244767

Thermal conductivity of Nickel is 105 W/m K, Iridium is 153 (copper is 413, that's why the cores are copper). So no, iridium is the better thermal conductor. That said, the area of the tip of the plug with precious metal plugs is usually smaller, so there's more surface area with the nickel alloy electrode. Both are roughly the same diameter from that point up through the body of the plug however.

Also, if we could isolate out all the variation between runs, the horsepower difference would be attributed to things like plug heat range, plug manufacturing variation, index/timing of the electrode strap relative to the injector, the actual tip geometry, and countless other more important factors.

 

[benjy]

surely opened a controversial subject, like oils!!! i installed the Champion #445 + her car "felt" smoother + the OE plugs did NOT LOOK good at 53 thou let alone 100 thou!! so if you have an EZE DIY change why waste your $$$. for more reading check out Dr Chris Jacobs old book still available + it notes his part in developing the variable rate PACEMAKER!!!

 

[benjy]

on another similar note i remember when dale armstrong, kenny bernstein developed his magnetos 44A ea + kennys fueler was beating most everyone until others caught up!!! Dr jacobs notes in his book using HOTTER ignitions but not suitable on a street car!! so much interesting improvements thru the years!!

 

[slacktide_bitog]

surely opened a controversial subject, like oils!!! i installed the Champion #445 + her car "felt" smoother + the OE plugs did NOT LOOK good at 53 thou let alone 100 thou!! so if you have an EZE DIY change why waste your $$$. for more reading check out Dr Chris Jacobs old book still available + it notes his part in developing the variable rate PACEMAKER!!!

Champion is garbage

If the factory iridium didn't look good at 53k, the Champion Losers might not even last 15k

If you still don't believe in iridium, Denso makes a Nickel TT, though it's not sold in the US. Part number is XUH22TT. Even though you already did the job, you'll have to do it again soon anyway. The iridium version is IXUH22FTT. Either of these, with international shipping, will end up costing more than the iridium or ruthenium from RA.

NGK cross-lists the Champion 445 to their #1693 (LKR7E). RA has them on closeout for about what you paid for the Champ Chimps, but the regular price for them is almost as much as the iridium for your Optima. They might still be worth ordering while they're on closeout, so you have them on hand when the Champions start losing.

 

[johnmyster]

I know but that's spark plugs 102

Also on the 102 level, the coil is an inductor, which means it tries to make/retain current, not voltage. It makes whatever voltage is necessary to jump the gap as the magnetic field collapses. Applying ohms law to a DC measured resistance is sketchy.