Spark Plug Clarification

[KiLLeR2001]

Been doing some research on spark plugs recently and found out that ALL CA18 / SR20 motors came factory equipped with platinum spark plugs (even non-turbo versions). And that got me thinking... I've been using BKR7E on my SR20 for years with no problems. Copper is the best y0! But then I did some more research and found out that BKR7E and similar "copper" plugs are not actually copper at the tip. These plugs have copper cores and nickel center and ground electrodes. Hmm... Nickel? Sounds lame.

The SR20DET uses the stock plug PFR6B-9 which is a double platinum plug. It still has a copper core like the "copper" plugs but the center and ground electrodes are made of platinum.

With that said, I will be switching to PFR7B (step colder) spark plugs on my SR because that is what the factory intended and I can't find any reason as to why nickel would be superior to platinum.

If anyone has had poor results with the PFR7B I'd like to hear about it.

Here are some links:

NGK BKR7E:
http://www.ngk.com/product.aspx?zpid=9349

NGK PFR7B:
http://www.ngk.com/product.aspx?zpid=9934

[S14DB]

http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

[g35gabby]

From what I remember, the Copper plug is "better" due for two main reasons. One because they are more cost effective than their platinum partners (you can buy a whole set of copper plugs for the price of 1 platinum) and because the Copper plugs do not retain heat as well as a platinum plug will. retaining heat can create pre-ignition, especially in boosted applications.

The only "draw back" I have ever found of using copper over any of the other "fancy" plugs, is their change intervals. My guess would be that factory uses that plug because it lasts significantly longer than the copper counter part and thus they don't have to service the under warranty.

[KiLLeR2001]

Well that's my whole point. There is no "copper" plug. In the link S14DB posted its laid out quite clearly. The basic plug is a nickel alloy, all plugs have copper cores. I usually notice my BKR7E's need replacing every 5,000 miles, platinum looks like it can go up to 100,000 miles. If this is true, than its most certainly cost effective to switch to platinum.

[ixfxi]

Did you read the sub-spec pages:

"Nickel is a hard, inexpensive metal used in most all spark plug designs. Nickel is not a good conductor and has a high level of resistance, so most center electrodes feature a copper core, covered in a nickel-alloy. This creates a balanced, team effort where the copper core conducts electricity and promotes heat dissipation, and the nickel-alloy outer material prolongs the life and durability of the Center Electrode.
While nickel is a choice material used in the majority of spark plug designs, it has its limitations. Tungsten and Iridium, for example are 2x harder and 3x stronger. Gold and Silver have minimal electrical resistance in comparison to nickel. And Iridium, Platinum, Rhodium, Titanium, Tungsten and Zirconium all have a higher melting point. Some of these precious metals are used to enhance nickel electrodes to prolong a plugs life in high performance designs."

and

"Nearly all spark plug manufacturers use platinum in one form or another on their long life or performance spark plugs. This is due to platinum’s high melting point, which makes it useful in two ways:
- On long life spark plugs a thin wafer of platinum is bonded at the firing point to the center electrode (and possibly ground electrode) solely so they don’t wear as fast as a traditional plug.
- On a fine wire performance plug, the very tip of the center electrode is tipped with, or made of, platinum so the thin tip will last longer.
Do not be fooled, all platinum plugs are not created equal. Platinum is a very expensive precious metal, a $2 platinum spark plug will not have much platinum in it, and therefore will not last as long as a $12 platinum spark plug. Some platinum plugs have only the center electrode tipped with platinum, while others have both the center and ground electrodes platinum tipped.

WARNING: It is not suggested that platinum plugs be used on vehicles with nitrous injection, however, there have been no problems reported using iridium plugs with nitrous."


To be honest, I've never noticed a big difference with all the various different plugs out there, cheap or expensive. I just cant see the difference other than change interval. On a street car, I just dont think it matters much. I feel the same way about synthetic engine oil.

[g35gabby]

Originally Posted by KiLLeR2001

Well that's my whole point. There is no "copper" plug. In the link S14DB posted its laid out quite clearly. The basic plug is a nickel alloy, all plugs have copper cores. I usually notice my BKR7E's need replacing every 5,000 miles, platinum looks like it can go up to 100,000 miles. If this is true, than its most certainly cost effective to switch to platinum.

100k is what they are marketed as, even a standard street car they start to degrade closer to 50k-60k under normal driving...

Copper, Nickle, pizza... I called it "copper" because that is what they are called, not because they are copper. I didn't have a better name for it.

I replaced them every 8k on my CA regardless of if they were dead or not. It was cheap insurance and avoiding detonation was worth the little extra "hassle" for me.

Are you having performance issues with the copper plugs that prompted the thought of a change? If I went away from the coppers, Iridium was always the next direction I would have gone, just for heat retention properties. then again, my car will rust away before it sees another 100k... so worrying about how long the plugs last isn't a big thing to me.

[S14DB]

There is no 100% copper plug. All of them are at least plated with something to prevent corrosion or that plug would be eaten away instantly.

The big difference is how much of the "core" is copper. 99c plugs are usually steel core with a copper/nickel coating. Some of the cheaper copper plugs "core" is a mm thick rest is steel.

Quality plugs the whole center electrode is copper with just a nickel coating.

Platinum plugs are just coatings to reduce fouling to increase service life. They are preferred because they are considered a "lifetime" part now. They also are not created equal. Steel cores, electrode isn't full face coated with platinum, only the center electrode is coated. Also, long life plugs tend to have big electrodes to last longer.

There are trade offs with platinum vs copper. Real ballers drop cash on iridium...

The real take away is whatever you go with. Buy a quality brand that you know how it's constructed. With what materials the plug is made up with and where. It's going to hurt you more to get some steel core junk coated in ubutanium than any full core plug coated in the 3 options mentioned.

[KiLLeR2001]

Originally Posted by g35gabby

Are you having performance issues with the copper plugs that prompted the thought of a change?

No issues, I just noticed all CA18 and SR20's alike came with platinums out of the factory, so that has to account for something. I'm not really expecting any performance changes, but even if the platinum plugs can last me until 50,000 miles it would still be a better deal than changing "nickel alloy" plugs every 5,000 miles.

[S14DB]

Originally Posted by KiLLeR2001

No issues, I just noticed all CA18 and SR20's alike came with platinums out of the factory, so that has to account for something. I'm not really expecting any performance changes, but even if the platinum plugs can last me until 50,000 miles it would still be a better deal than changing "nickel alloy" plugs every 5,000 miles.

Production cars are a collection of compromises. Why we tune and upgrade them.

[ixfxi]

Originally Posted by S14DB

There is no 100% copper plug. All of them are at least plated with something to prevent corrosion or that plug would be eaten away instantly.

i dont think its a matter of corrosion, its more a matter of hardness to protect the electrode. its not like the spark plug is subjected to corrosive elements. the exert below clearly says that the nickel is used to make the plug more durable

Originally Posted by KiLLeR2001

it would still be a better deal than changing "nickel alloy" plugs every 5,000 miles.

and i dont think that there is anything wrong with using a plug that is nickel alloy. i think its more important to simply buy a quality plug from a quality mfg and do your due diligence when it comes to maintenance

ive been running NGKs forever, i cant ever think of a time where they failed. on the SR, I run what the FSM suggests... either platinum or iridium, i cant remember since my motor has been sitting pretty for the last decade now

[KiLLeR2001]

Looks like nickel is about 1.52X more conductive than platinum. And iridium is 1.3X more conductive than nickel. Making iridium about 2X more conductive than platinum.

At $14 a plug for the laser iridium its hard to swallow. Not to mention you have to be extremely careful gapping them.

Looks like nickel plugs are still king for price and simplicity... And if you got a little extra coin switch to iridium IX ($28 for 4) for a little bit better conductivity but being that the ground electrode is still nickel, it's only an improvement on tip longevity and conductivity... NGK says longevity is around 50,000 miles on the Iridium IX and 100,000 miles on the Laser Iridium. If this is true than ultimately Iridium IX would be the best for performance/value!

http://www.ngksparkplugs.com/pdf/DYK...idium%20IX.pdf

[crzsteveo]

good info. ive been using iridium on my ka. wouldn't a copper core be better for conductive purposes than a steel?

[KiLLeR2001]

Well as far as, BKR7E (nickel), BKR7EIX (iridium), and the PFR7B (platinum) which are all NGK... They all have copper cores. I wouldn't attempt to put anything other than NGK in my engine (personal preference).