Pro shops are tools...

[St-Gerard]

PS don't drop the plug on concrete , It is now trash.

 

[The Dark Shadow]

What would you say about this conclusion?

I would say you make some interesting points. And I would repeat that I am no engine engineering expert.

But, there is clearly a reason Honda wants the collar on the spark plugs.

If you've ever done plumbing, you know that even-spaced parallel threads (non-tapered fitments) pretty much ALWAYS leak, hence we use washers and/or Teflon tape. When we tighten a spark plug, only one edge of each set of threads (the threaded hole in the engine casing and the threaded spark plug) make tight contact with each other. This will allow seepage from the inner cylinder chamber past the threads above the threaded engine hole portion to the area between thread engagement and the gasket. Perhaps some engines have threads that continue all the way to the gasket, but I have no idea. This Honda engine clearly has threads that engage approximately halfway along the "barrel" of the spark plug (the barrel is the layman's term I use for the fully threaded portion on non-H plugs, and the thread+collar portion on the "H" plugs). This leaves a "cavity" above the portion of thread engagement. (Lots of words, simpler in a diagram.)

So, with an engine explosion there is higher pressure in the engine, and the exploding gases will seep somewhat through the threads to the "cavity" area, then there will be a cycle where the cylinder internal pressure lowers, and some of the seepage into the cavity will return to
the cylinder bore. This cycling will continue.

It seems logical that the more of this cavity that is filled up, the less back-and-forth seepage will occur. When the cooler air-fuel mixture enters the cylinder chamber then compresses before ignition, if there is seepage into this cavity area, that will increase the amount of cool air-fuel making contact with the cavity area of the spark plug, which logically should cool the plug slightly more if this cavity isn't filled with a collar versus if the cavity is indeed filled with a collar.

The "H" designation on NGK's given reference chart states "half thread". At first, this didn't quite make sense, since the threads are still more than half of the height of the barrel (ie: more than half of 19mm). But, the engagement point of the threads is halfway down this barrel, the designation "half" makes more sense. I don't know the thickness of the engine threaded wall, but it's gotta be near 4 millimetres minimum.

Honda quite clearly has designed an engine with spark plug openings where the threads do not engage to the full depth of the thread all the way to the gasket. Perhaps other engines are designed with threads that go all the way to the gasket.

I drew a diagram. In the non-H plug, clearly there will be more seepage. Whether this is enough to cool the barrel more that the plugged-cavity-H (collared) plugs, I know not. But theoretically it makes 100% logical sense that there will be some small effect.

I attached a diagram, and a photo of my non-H plug which clearly shows seepage nearly completely down to the gasket. The seepage clearly goes into the "cavity" area above the thread-engagements point.

Whether this difference alone is enough to affect engine performance, I know not. But I expect it has some sort of effect.

We mustn't forget however what is likely a significant difference that I just sleuthed yesterday - the .8mm gap (non-H plugs) versus the .9mm gap ("H" plugs). After I finish this message, I'm gonna do some information sleuthing on "what if your spark plug gap is too little". It seems likely that the spark is smaller and less powerful.

Thanks for your question... In considering and writing a response, I've clued in on yet another interesting point as I've written.

* UPDATE: First hit on "what happens if your spark plug gap is too small rich lean". See attachment 3 (a screenshot). This is exactly the conclusion I was drawing towards.

 

[The Dark Shadow]

BTW... Open question for anyone...

What does the condition of my spark plugs tell you about the state of my engine combustion...??

I know my answer, and I'm quite confident with it. But it will be nice to compare my answer to others, since I was told quite obstinately that these .8mm spark plugs work just as Honda planned, even though Honda's recommended plugs have a .9mm gap.

Cheers!

 

[Al st1100]

As will any standard plug in a properly running engine.

if your lucky, Standard spark plug gaps will wear much faster. The electrode gap normally increases from spark firing and this happens faster with standard plugs. Iridium plug gaps wear more slowly so they will last 100K miles or a little more. Regular plugs will wear out in 15K miles and platinum plugs wear out in 30–50K miles.

 

[Andrew Shadow]

if your lucky, Standard spark plug gaps will wear much faster. The electrode gap normally increases from spark firing and this happens faster with standard plugs. Iridium plug gaps wear more slowly so they will last 100K miles or a little more.

I am not disagreeing with you that an iridium plug has a longer life-span. My point is that to claim that the switch to iridium plugs is to take advantage of the greater change interval afforded by their increased life-span and to then replace them every 15 or 20,000 miles is false economy and makes no sense. The standard plugs will easily last double that mileage, so there is no gain at all unless the interval is significantly increased. If a person is going to replace their spark plugs that often, they would be far better off to buy the standard plugs and put the cost difference in their gas tank.

Regular plugs will wear out in 15K miles ......

Sure, in the days of points and condenser ignition systems and carbureted engines running leaded gas that was true. Spark plugs needing to be changed at 15,000 mile intervals has not been the case since electronic ignition and fuel injection became standard. Regular plugs do not wear out anywhere near 15,000 miles unless they are some cheap counterfeit made-in-China rip-offs or their is something wrong with the vehicle that precipitates premature spark plug failure. As far back as the mid to late eighties the spark plugs delivered with a new vehicle were warranteed for 80,000 KM/50,000 miles under government emissions regulations, as were all other parts that fell under that legislation.

...... platinum plugs wear out in 30–50K miles.

My truck is a 2010 and it came from the factory equipped with iridium plugs. The first inspection and replacement of the spark plugs is called for at 160,000 KM/100,0000 miles, and every 160,000 KM/100,00 miles thereafter. This is with the iridium spark plug technology of 20 years ago. I would hope that the current technology is superior, so the numbers that you are offering make no sense.

 

[motornut]

A spark plug is designed to arc across a air gap to create the ignition of the fuel air mixture. The thing with any plug is it will discharge the coil and that will end the spark, at each spark a small amount is metal is eroded from the electrodes, hence the metal changes in the electrodes to resist erosion. The demand for more spark is made up by a " reserve capacity " in the coil, less resistance from the plug means the coil will discharge with lower amperage. And the coil will discharge and that is all over until the resistance exceeds the coil capacity. The electrode differences are to reduce erosion.
. In this the iridium, platinum or any other plugs work very well, Improved gas mileage and smoother idle means the original plugs are in fact worn out and needed replacement. If they had been replaced with standard plug it would have run better too. Just not as long as the preferred upgraded plug.
It goes back to the recommendation that if its not running right- the plugs are a good place to start. I am not in anyway denigrating up dating the plugs at all. I have found that I have not needed them. With fuel injection the plugs last a lot longer no matter what they are, my old carbed cars I changed them once a year as well as changing the points and adjusting the timing.
A carb is designed to operate at most efficient at wide open throttle. fuel injection adjusted where carburetors could not.

 

[Larry Fine]

A carb is designed to operate at most efficient at wide open throttle. fuel injection adjusted where carburetors could not.

But clean, well-adjusted CV carbs do a pretty good job.

 

[Al st1100]

I am not disagreeing with you that an iridium plug has a longer life-span. My point is that to claim that the switch to iridium plugs is to take advantage of the greater change interval afforded by their increased life-span and to then replace them every 15 or 20,000 miles is false economy and makes no sense. The standard plugs will easily last double that mileage, so there is no gain at all unless the interval is significantly increased. If a person is going to replace their spark plugs that often, they would be far better off to buy the standard plugs and put the cost difference in their gas tank.

Sure, in the days of points and condenser ignition systems and carbureted engines running leaded gas that was true. Spark plugs needing to be changed at 15,000 mile intervals has not been the case since electronic ignition and fuel injection became standard. Regular plugs do not wear out anywhere near 15,000 miles unless they are some cheap counterfeit made-in-China rip-offs or their is something wrong with the vehicle that precipitates premature spark plug failure. As far back as the mid to late eighties the spark plugs delivered with a new vehicle were warranteed for 80,000 KM/50,000 miles under government emissions regulations, as were all other parts that fell under that legislation.

My truck is a 2010 and it came from the factory equipped with iridium plugs. The first inspection and replacement of the spark plugs is called for at 160,000 KM/100,0000 miles, and every 160,000 KM/100,00 miles thereafter. This is with the iridium spark plug technology of 20 years ago. I would hope that the current technology is superior, so the numbers that you are offering make no sense.

Why would anyone change iridium plugs after 15-20k, makes no sence, as soon as they pulled them out they would appear brand new, they have not degraded. It's like changing your synthetic oil every 3000 miles.
As far as this "As far back as the mid to late eighties the spark plugs delivered with a new vehicle were warranteed for 80,000 KM/50,000 miles under government emissions regulations, as were all other parts that fell under that legislation." I have works at a few new car dealerships over the last 40 sum years and never ever heard of such a thing.

 

[DannoXYZ]

Yeah, I've gone +100k-miles on all my iridium plugs on bikes and autos.

Don't see how they would improve performance in any way.

Maybe if you have marginally sufficient ignition to begin with, tiny point of iridium centre may concentrate spark more and help ionize air better. But with modern electronic ignition, it should be more than powerful enough to ignite mixture with any plug.

 

[Andrew Shadow]

Why would anyone change iridium plugs after 15-20k, makes no sence, as soon as they pulled them out they would appear brand new, they have not degraded. It's like changing your synthetic oil every 3000 miles.

My point exactly, but this is what some people do and why I am often at a loss to understand the logic used to make this switch to iridium plugs. Anyone changing standard plugs at 15,000 miles is throwing away money, let alone doing so with iridium plugs.

As far as this "As far back as the mid to late eighties the spark plugs delivered with a new vehicle were warranteed for 80,000 KM/50,000 miles under government emissions regulations, as were all other parts that fell under that legislation." I have works at a few new car dealerships over the last 40 sum years and never ever heard of such a thing.

These are not new regulations. Every dealer should be familiar with them. The original regulations came out in the US in 1972 and have been amended over time. I was a mechanic at a GM dealership for many years, which is why I am familiar with this because so much of the work that we did was under warranty. I was not responsible to US regulation but as far as I know in the US this fell under the Clean-Air Act regulations. We had similar legislation here in Canada. The regulations were very similar in both countries as is most often the case with automobiles.

Specified emissions parts fell under federal government regulations that mandated that in the case that these parts failed they had to be replaced under the warranty stipulated in the regulation regardless of what the manufacturers warranty was. At the time this was 5 years or 80,000KM in Canada, 50,000 miles in the US. Spark plugs were included, as well other specified parts whose performance directly affected emissions such as catalytic converters, EGR valves, high tension wires, etc.. In the US starting in the mid ninties the regulations changed and fewer parts were included on the list but the warranty period was extended to 8 years or 80,000 miles for the specified emissions parts. I have no idea what the current regulations are.

This did not mean that you could drive in to a dealer and expect to get all of your spark plugs, or all of your high tensdion wires replaced under warranty and get a cheap tune-up. That's not how it worked. It only covered defective parts. e.g. If a car came in missing on one cylinder and a defective spark plug or a defective high tension wire was the cause, that one spark plug or wire was replaced under warranty if the car was within the 5 year/80,000Km (50,000 miles in the US) emissions warranty period. If that same car came in and the customer asked to have all of the spark plugs replaced, that was a routine maintenance event and not covered under warranty.

 

[Al st1100]

My point exactly, but this is what some people do and why I am often at a loss to understand the logic used to make this switch to iridium plugs. Anyone changing standard plugs at 15,000 miles is throwing away money, let alone doing so with iridium plugs

Specified emissions parts fell under federal government regulations that mandated that in the case that these parts failed they had to be replaced under the warranty stipulated in the regulation regardless of what the manufacturers warranty was. At the time this was 5 years or 80,000KM in Canada, 50,000 miles in the US. Spark plugs were included, as well other specified parts whose performance directly affected emissions such as catalytic converters, EGR valves, high tension wires, etc.. In the US starting in the mid ninties the regulations changed and fewer parts were included on the list but the warranty period was extended to 8 years or 80,000 miles for the specified emissions parts. I have no idea what the current regulations are.

I also worked for gm ( loved those electronic carbs) and mopar but our (US) Fed standards must be way different than Canada. US (epa) standards only covered ECM an converters for 8/80k miles all the other stuff was 2/24. This article explains 95 and newer but it was all I could find https://mde.maryland.gov/programs/Air/MobileSources/Documents/www.mde.state.md.us/assets/document/warr95fs.pdf

 

[dbst1300]

As will any standard plug in a properly running engine.

There are NGK plug problems on the advrider.com BMW GS forum. I checked my 2022 R1250GS plugs at 12,000 miles, they looked good, and were junk at 16,000 miles. No definite fix other than to replace them at 12,000 miles at $50.00 for the pair.

https://advrider.com/f/threads/r-1250-engine-ngk-lmra8ai-10-spark-plug-failures-need-your-help.1712903/

 

[The Dark Shadow]

There are NGK plug problems on the advrider.com BMW GS forum. I checked my 2022 R1250GS plugs at 12,000 miles, they looked good, and were junk at 16,000 miles. No definite fix other than to replace them at 12,000 miles at $50.00 for the pair.

https://advrider.com/f/threads/r-1250-engine-ngk-lmra8ai-10-spark-plug-failures-need-your-help.1712903/

Could those NGK problems actually have been counterfeit issues as Igofar mentioned earlier in this thread...?

 

[dbst1300]

Could those NGK problems actually have been counterfeit issues as Igofar mentioned earlier in this thread...?

Mine were OEM from new……and per the info I read appeared to be genuine NGK plugs. Maybe BMW bought a defective supply of plugs?

Fake or not?

Beware of fake NGK spark plugs: 5 step guide how to identify fake vs genuine by NGK spark plugs technical experts ✓

www.ngkntk.com

 

[Andrew Shadow]

I also worked for gm ( loved those electronic carbs) and mopar but our (US) Fed standards must be way different than Canada. US (epa) standards only covered ECM an converters for 8/80k miles all the other stuff was 2/24. This article explains 95 and newer but it was all I could find https://mde.maryland.gov/programs/Air/MobileSources/Documents/www.mde.state.md.us/assets/document/warr95fs.pdf

I know, I already referred to those changes.

In the US starting in the mid ninties the regulations changed and fewer parts were included on the list but the warranty period was extended to 8 years or 80,000 miles for the specified emissions parts. I have no idea what the current regulations are.

Before these changes were made in the mid nineties many more parts were included in the US and Canadian emissions regulations.

I also stated that I don't know what the current regulations are, in Canada or the US. Even so, I strongly suspect that there is still very little difference between the two countries as there rarely is with regard to automobiles. There is a lot of synergy between the regulations in both countries because in reality it really is one market.

 

[Andrew Shadow]

There are NGK plug problems on the advrider.com BMW GS forum. I checked my 2022 R1250GS plugs at 12,000 miles, they looked good, and were junk at 16,000 miles. No definite fix other than to replace them at 12,000 miles at $50.00 for the pair.

https://advrider.com/f/threads/r-1250-engine-ngk-lmra8ai-10-spark-plug-failures-need-your-help.1712903/

So far at least, that seems to be a problem with a specific iridium spark plug, and is not indicative of overall spark plug life expectancy be they standard or iridium.

 

[Al st1100]

So far at least, that seems to be a problem with a specific iridium spark plug, and is not indicative of overall spark plug life expectancy be they standard or iridium.

plug or engine?

 

[The Dark Shadow]

So far at least, that seems to be a problem with a specific iridium spark plug, and is not indicative of overall spark plug life expectancy be they standard or iridium.

So my above joking comment that it could be a BMW issue might actually be right, due to their possible design specifications to manufacture...??

 

[Andrew Shadow]

plug or engine?

So my above joking comment that it could be a BMW issue might actually be right, due to their possible design specifications to manufacture...??

No clue to both questions. I'm not paying attention to it as I don't have a BMW and I don't use iridium spark plugs.

 

[Andrew Shadow]

As far as this "As far back as the mid to late eighties the spark plugs delivered with a new vehicle were warranteed for 80,000 KM/50,000 miles under government emissions regulations, as were all other parts that fell under that legislation." I have works at a few new car dealerships over the last 40 sum years and never ever heard of such a thing.

Al:

I was looking at a 2022 Ford truck the other day and had a look at the warranty manual because I remembered this discussion. Below is a list of what is covered under the US Federal emissions warranty for that 2022 model year. These parts are covered for 5 years/50,000 miles. This list is for heavy duty vehicles, which is vehicles over 8,500 gross pounds. It does not apply to passenger cars and light duty vehicles. I am referencing it to give an idea of how extensive the list is. This list is similar to what used to be included under the emission warranty for passenger vehicles before the changes that were made in the early or mid nineties, I can't remember, save all of the newly added electronic parts that didn't exist back then of course.

I find it curious that it is still such an extensive list for heavy duty vehicles while it was changed to cover almost nothing for passenger vehicles. I have no idea why that would be.
I also don't see why some of these parts are on the list but someone in the EPA considered them emissions parts I guess.


Heavy duty vehicles (applies to trucks over 8,500 pounds GVWR up to 19,500 pounds GVWR) — 5 years or 50,000 miles (whichever occurs first) for all covered parts.
WHAT IS COVERED?
If these parts contain an emissions-related defect, they are covered by both the Emissions Defect Warranty and the Emissions Performance Warranty.
• Air Flow Sensor
• Air/Fuel Feedback Control System and Sensors
• Air Induction System
• Battery Energy Control Module (BECM)
• Brake Hydraulic/Electric Control Assembly (Plug-in Hybrid vehicles only)
• Brake Vacuum Pump (Plug-in Hybrid vehicles only)
• Catalytic Converters (including Selective Catalytic Reduction and Diesel Oxidation Catalysts)
• Charger and Bracket Assembly High Voltage Battery (Hybrid and Plug-in Hybrid vehicles only)
• Cold Start Enrichment System (diesel only)
• Controls for Deceleration (diesel only)
• Converter and Bracket Assembly High Voltage to Low Voltage (Hybrid and Plug-in Hybrid vehicles only)
• Diesel Exhaust Fluid System
• Diesel Particulate Filter
• Electronic Ignition System (diesel only)
• Electronic Engine Control Sensors and Switches
• Powertrain Control Module (PCM)/Engine Control Module (ECM)*
• Evaporative Emission ControlSystem
• Exhaust Gas Recirculation (EGR) System
• Exhaust Manifold
• Exhaust Pipe (Manifold to Catalyst)
• Fuel Filler Door Sensor (Hybrid and Plug-in Hybrid vehicles only)
• Fuel Filler Tube and Seal (non-diesel only)
• Fuel Injection System
• Fuel Injector Supply Manifold
• Fuel Tank (non-diesel only)
• Fuel Tank Pressure Control Valve
• Heating Element of Back Window (3.0L diesel F-150 only)
• High Voltage Battery (Hybrid and Plug-in Hybrid vehicles only)
• HVAC Controller (Plug-in Hybrid vehicles only)
• Ignition Coil and/or Control Module
• Intake Manifold
• Intercooler Assembly - Engine Charger
• Inverter System Controller (Plug-in Hybrid vehicles only)
• Jumper Assembly Charge Inlet to Charger (Hybrid and Plug-in Hybrid vehicles only)
• Jumper Assembly DC/DC Converter to High Voltage Panel (Hybrid and Plug-in Hybrid vehicles only)
• Malfunction Indicator Lamp (MIL)/On-Board Diagnostic (OBD) System
• Module and Bracket Assembly Transmission Inverter Control (Hybrid and Plug-in Hybrid vehicles only)
• Motor Electronics Coolant Pump (Plug-in Hybrid vehicles only)
• PCV system and Oil Filler Cap • Onboard Charger (Plug-in Hybrid vehicles only)
• Secondary Air Injection System • Spark Control Components
• Spark Plugs and Ignition Wires
• Thermostat
• Throttle Body Assembly (MFI)
• Transmission Assembly (Plug-in Hybrid vehicles only)
• Transmission Auxiliary Oil Pump (Plug-in Hybrid vehicles only)
• Transmission Fluid Temperature Sensor (Plug-in Hybrid vehicles only)
• Transmission Control Module (TCM) and Solenoids
• Turbocharger Assembly
• Vacuum Distribution System
* Includes hardware and emissions related software changes only

Also covered by the two emissions warranties are all emissions-related bulbs, hoses, clamps, brackets, tubes, gaskets, seals, belts, connectors, non-diesel fuel lines, sensors, and wiring harnesses that are used with components on the list of parts, above.