Which plug type?
- Thread starter brinu
- Start date
I would start with the same heat range and gap. You might be able to run a bigger gap depending on how much headroom the system has but I would not bother outside of curiosity.
Definitely suitable for any engine if they make one to fit it.
The problem with iridium is changing the gap can damage the very small electrode - most come pre-gapped by application. Most will likely be gapped much further than your old car wants. Be very careful changing the gap not to damage the electrode.
I have discovered, through personal experience, that exotic spark plugs don't do well in older engines. Never, ever put them in a waste spark system.
They're actually perfect for waste spark ignition because the dual, durable, electrodes prevent wear in both polarities while also reducing the voltage required.
A single platinum / iridium plug can do well with COP or distributed ignition because each plug is fired with the same polarity voltage and reduce the wear associated. A dual platinum / iridium plug can prevent wear in waste spark where pairs of plugs are wired in series, with one reversed.
On my Honda I use the plug that came with it...
I’ve got NGK IX Iridiums in a Ford Taurus with a waste spark system. They were spec’d for the application on Rock Auto. No problems after a year.
I tried iridium's in three different waste spark vehicles I owned. Within six months the center electrode on half the plugs disappeared in all three vehicles. Money (a lot) wasted. I've heard of other's having the same issues.
As far as the coil goes, I'ts going to put out it's rated voltage no matter whats at the other end. Only the current changes. When you reduce the plug resistance, as exotic plugs claim, the resistance goes down and the current goes up and that's not a good thing.
Waste spark systems were never designed for exotic plugs. When the plug fires in the reverse direction (ground electrode to center conductor) on a non-compression (waste) cycle there is virtually no resistance for electrical path (as apposed to trying to fire under compression) and current goes sky high. I believe this is why the center electrode in waste spark systems burn away up to the insulator.
I have posted photos of platinum plugs that support those observations. On the Taurus V-6, the front bank plug’s center electrodes get worn down. The rear bank just gets normal wear. On the Ford Ranger with the same Vulcan engine, the left bank gets worn and the right bank doesn’t.
Next time my daughter brings the Taurus over, I’ll pull a front plug, which is easy, and photograph it. They are NGK IX Iridium plugs.
To be fair we need to get the mileage and the actual make and model of the spark plugs in question.
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Here are the platinum plugs I pulled a year ago fom a Taurus with a waste spark ignition. The top three are from the back set and have little wear. The bottom three are from the front bank and are quite worn.
Yeah, those aren't iridium, those are fake / counterfeit. There's several videos detailing the problem and NGK has some information on how to check. Rule #1 is don't buy plugs from ebay / Amazon / 3rd party sellers. Platinum, iridium, ruthenium electrodes last an extremely long time (50k - 150k miles?) and will provide very consistent spark quality over their lifetime.
Waste spark pretty much disappeared when the individual coil per sparkplug came along. The Vulcan engine in the Taurus disappeared around 2008 and the Ford Fusion replacing the Taurus had individual coils for each sparkplug. That’s 18 years ago.
Oh, now your going to throw in the fake / counterfeit argument?
Yea, in the right application.
Please learn some basic electricity.
Like I said, fake, expensive NGK plugs (and other makes) are all over the place. If you're careful you can detect the fakes but that doesn't mean you can get your money back. Real NGK platinum / iridium / ruthenium (dual electrode) plugs are perfect for waste-spark ignition systems and will outlast a standard plug by 5-10x. They reduce the voltage require to arc due to their geometry (shape) and resistance to wear (stay sharp longer).
This voltage reduction means that you can:
- run a larger gap
- run higher boost
- get a longer / hotter arc
- less misfire in compromised situations (failing coil / wire, lean mixture, etc)
... but this does not mean you will see any improvement.
Just to clarify, you can get single and dual electrode plugs from NGK. I would not recommend single electrode plugs (platinum or iridium) in any waste-spark system. It's not always easy to understand before purchase if you are getting a single or dual electrode.
G-Power Platinum are all singles, platinum only on the center electrode
Laser plugs, I think, are all dual electrodes.
G-Power Platinum are all singles, platinum only on the center electrode
Laser plugs, I think, are all dual electrodes.
You have no clue about what your talking about...
Why are you drifting away from the original manufacturer-specified plug? Do you want a longer change interval? Other than that not sure you'll see any real benefit for the extra money. Just curious.
TLDR: People buy spark plugs thinking they are original / quality when they are actually fake. Fake spark plugs are not good and people get upset.
I've had engines running poorly or not starting reliably and tried "everything" except replacing the ignition coil(s) due to access issues (remote location, difficult access, several hours required). Replacing a standard plug with a single-platinum improved the starting, closing the gap got it running smooth.
This engine was a generator running on NG (natural gas) and I know they run lean and often require reduced spark-gap to start reliably. I switched the standard plug for an NGK G-Power (single platinum, same gap) and it would start but ran rough. Reducing the gap got it running smooth. I called it a day and on the next service opportunity I replaced the ignition coils. The lesson here was that reducing the voltage required improved the ignition and this was accomplished by using a fine/sharp tipped electrode (platinum) and reducing the gap.
This engine had failed to start several times over a month before swapping in the platinum plugs. It then ran reliably for several months until the ignition coils could be replaced. I surmised that the old ignition coils were getting weak but had not failed. The engine ran great on the new coils with either the original plug, reduced gap plug or the platinum plug. I now use NGK G-Power in all my equipment and in service.
