Any experience of best spark plugs?

[BigM]

Seeing some posts i realized may need to change the plugs. Any input on what would be the best performance and longivity for I/S At 107k miles?

[signart]

NGK DPR7EA9

[gordonv]

Read enough info and there is controversy. Whether or not to change plugs?

I have changed many plugs in cars, and some motorcycles, and have always monitored my fuel economy. It had never changed before or after changing plugs when told to for maintenance. The last plugs I changed in a MC where to Iridium, and the same in my new-to-me car.

Plugs good for 100K miles. About 3x-4x the cost of stock plugs, but for piece of mind, shouldn't ever be required to change them again, unless my fuel economy changes.

[98valk]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

[Fireman973]

NGK DPR7EA9 Changed today. Like an oil change, it's not hard (other than the I/S pods), and it is satisfying to spend quality time with the Valkyrie.

[Chrisj CMA]

NGK DPR7EA9

+1 and buy from car parts place not a motorcycle dealer

[Gryphon Rider]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

[98valk]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

they're pushing their plug, http://www.weaponxperformance.com/technicalPDF/SPARK_PLUG_TECH_V1.pdf    but the info/testing is sound. u can search for more.   read the plug wires about low resistance http://www.magnecor.com/magnecor1/main.htm
"Low-resistance" conductors are an easy sell, as most people associate all ignition wire conductors with original equipment and replacement ignition wire carbon conductors (which progressively fail as a result of microscopic carbon granules burning away and thus reducing the spark energy to the spark plugs) and with solid wire zero-resistance conductors that were used by racers with no need for suppression. Consumers are easily led into believing that if a spiral conductor's resistance is almost zero, its performance must be similar to that of a solid metal conductor all race cars once used. HOWEVER, NOTHING IS FURTHER FROM THE TRUTH!

What is not generally understood (or is ignored) is that as a result of the laws of electricity, the potential 45,000 plus volts (with alternating current characteristics) from the ignition coil (a pulse type transformer) does not flow through the entire length of fine wire used for a spiral conductor like the 1 volt DC voltage from a test ohmmeter, but flows in a magnetic field surrounding the outermost surface of the spiral windings (skin effect). The same skin effect applies equally to the same pulsating flow of current passing through carbon and solid metal conductors.

A spiral conductor with a low electrical resistance measured by an ohmmeter indicates, in reality, nothing other than less of the expensive fine wire is used for the conductor windings — a construction which cannot achieve a clean and efficient current flow through the magnetic field surrounding the windings, resulting in poor suppression for RFI and EMI.

Of course, ignition wire manufacturers save a considerable amount in manufacturing costs by using less fine wire, less exotic winding machinery and less expertise to make low-resistance spiral conductors. As an incentive, they find a lucrative market amongst performance parts marketers who advertise their branded ignition wires as having "low-resistance" conductors, despite the fact that such "low-resistance" contributes nothing to make spiral ignition wires perform better, and both RFI and EMI suppression are compromised.

[WintrSol]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

A smaller center electrode doesn't magically reduce the Voltage requirement, but it does concentrate the spark in a smaller space, making it more effective. Combine that with the harder material, and you have an effectively hotter spark combined with a longer lasting tip.

[Gryphon Rider]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

they're pushing their plug, but the info/testing is sound. u can search for more.   read the plug wires about low resistance http://www.magnecor.com/magnecor1/main.htm
"Low-resistance" conductors are an easy sell, as most people associate all ignition wire conductors with original equipment and replacement ignition wire carbon conductors (which progressively fail as a result of microscopic carbon granules burning away and thus reducing the spark energy to the spark plugs) and with solid wire zero-resistance conductors that were used by racers with no need for suppression. Consumers are easily led into believing that if a spiral conductor's resistance is almost zero, its performance must be similar to that of a solid metal conductor all race cars once used. HOWEVER, NOTHING IS FURTHER FROM THE TRUTH!

What is not generally understood (or is ignored) is that as a result of the laws of electricity, the potential 45,000 plus volts (with alternating current characteristics) from the ignition coil (a pulse type transformer) does not flow through the entire length of fine wire used for a spiral conductor like the 1 volt DC voltage from a test ohmmeter, but flows in a magnetic field surrounding the outermost surface of the spiral windings (skin effect). The same skin effect applies equally to the same pulsating flow of current passing through carbon and solid metal conductors.

A spiral conductor with a low electrical resistance measured by an ohmmeter indicates, in reality, nothing other than less of the expensive fine wire is used for the conductor windings — a construction which cannot achieve a clean and efficient current flow through the magnetic field surrounding the windings, resulting in poor suppression for RFI and EMI.

Of course, ignition wire manufacturers save a considerable amount in manufacturing costs by using less fine wire, less exotic winding machinery and less expertise to make low-resistance spiral conductors. As an incentive, they find a lucrative market amongst performance parts marketers who advertise their branded ignition wires as having "low-resistance" conductors, despite the fact that such "low-resistance" contributes nothing to make spiral ignition wires perform better, and both RFI and EMI suppression are compromised.

But my question was about the centre electrode of the spark plug, not about the wire.

[98valk]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

they're pushing their plug, but the info/testing is sound. u can search for more.   read the plug wires about low resistance http://www.magnecor.com/magnecor1/main.htm
"Low-resistance" conductors are an easy sell, as most people associate all ignition wire conductors with original equipment and replacement ignition wire carbon conductors (which progressively fail as a result of microscopic carbon granules burning away and thus reducing the spark energy to the spark plugs) and with solid wire zero-resistance conductors that were used by racers with no need for suppression. Consumers are easily led into believing that if a spiral conductor's resistance is almost zero, its performance must be similar to that of a solid metal conductor all race cars once used. HOWEVER, NOTHING IS FURTHER FROM THE TRUTH!

What is not generally understood (or is ignored) is that as a result of the laws of electricity, the potential 45,000 plus volts (with alternating current characteristics) from the ignition coil (a pulse type transformer) does not flow through the entire length of fine wire used for a spiral conductor like the 1 volt DC voltage from a test ohmmeter, but flows in a magnetic field surrounding the outermost surface of the spiral windings (skin effect). The same skin effect applies equally to the same pulsating flow of current passing through carbon and solid metal conductors.

A spiral conductor with a low electrical resistance measured by an ohmmeter indicates, in reality, nothing other than less of the expensive fine wire is used for the conductor windings — a construction which cannot achieve a clean and efficient current flow through the magnetic field surrounding the windings, resulting in poor suppression for RFI and EMI.

Of course, ignition wire manufacturers save a considerable amount in manufacturing costs by using less fine wire, less exotic winding machinery and less expertise to make low-resistance spiral conductors. As an incentive, they find a lucrative market amongst performance parts marketers who advertise their branded ignition wires as having "low-resistance" conductors, despite the fact that such "low-resistance" contributes nothing to make spiral ignition wires perform better, and both RFI and EMI suppression are compromised.

But my question was about the centre electrode of the spark plug, not about the wire.

it would be good if I posted the link  http://www.weaponxperformance.com/technicalPDF/SPARK_PLUG_TECH_V1.pdf

[Gryphon Rider]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

A smaller center electrode doesn't magically reduce the Voltage requirement, but it does concentrate the spark in a smaller space, making it more effective. Combine that with the harder material, and you have an effectively hotter spark combined with a longer lasting tip.

Okay, I found the Wikipedia Spark plug article to be helpful:

In addition, electrons are emitted where the electrical field strength is greatest; this is from wherever the radius of curvature of the surface is smallest, from a sharp point or edge rather than a flat surface.
...
It would be easiest to pull electrons from a pointed electrode but a pointed electrode would erode after only a few seconds. Instead, the electrons emit from the sharp edges of the end of the electrode; as these edges erode, the spark becomes weaker and less reliable.
...
The development of noble metal high temperature electrodes (using metals such as yttrium, iridium, tungsten, or palladium, as well as the relatively high value platinum, silver or gold) allows the use of a smaller center wire, which has sharper edges but will not melt or corrode away. These materials are used because of their high melting points and durability, not because of their electrical conductivity (which is irrelevant in series with the plug resistor or wires). The smaller electrode also absorbs less heat from the spark and initial flame energy.

[Jess from VA]

The OE cheapo NGKs or Nippon Denso work perfectly for tens of thousands of miles (on a well tuned bike).

If I paid for Iridium, I'd feel compelled to leave them in for a LONG time.  With the NGKs, I can splurge every few years for a few bux.  

I had an old Hog that noticeably improved with hot rod dual electrodes and split-fire plugs.  But you only had to buy two, and the old ones were always carboned up and oily (unlike valk plugs).  

[WintrSol]

The OE cheapo NGKs or Nippon Denso work perfectly for tens of thousands of miles (on a well tuned bike).

If I paid for Iridium, I'd feel compelled to leave them in for a LONG time.  With the NGKs, I can splurge every few years for a few bux.  

Yes, regular OEM plugs work fine, but the point of the iridium plugs is that you CAN leave them in longer, assuming your engine burns clean. Now, in a bike with a really weak spark, like the '70 CB450, I noted an immediate improvement in starting and high rpm running, that lasts several more years than a new set of OEM plugs.

[98valk]

since the ignition system is not as strong as it should be, mainly the coils, any help in reducing the required arc jump voltage is the way to go. This means a plug with a reduced center electrode. So either $$$$ iridium as mentioned or what I use the new champion powersport plugs by federal mogul with reduced center electrode, was using same design autolites.
in use for two yrs zero problem and wear. Top cap unscrews for OEM plug cables.
CHAMPION POWERSPORT SPARKPLUG 8812 RA8HC, RA8GHC, D6EA - can also be found in a pack of 8

How does a smaller centre electrode reduce the amount of voltage required?  I can see that anything that reduces resistance in the circuit to and from the gap would help, ensuring full voltage gets to the gap, and anything to ensure the surfaces of the electrodes are as conductive and wear resistant as possible would help so the gap doesn't wear to be larger than ideal, but I can't immediately see the advantage of a smaller electrode.

if u want to learn more see Dr C Jacobs book. I stated the reduced voltage requirement which makes it easier to jump the spark gap and which reduces the inherent small % misfires with standard plugs as he does. I have had his first book since '96.  
http://www.e-bookdownload.net/search/the-doctor-s-step-by-step-guide-to-optimizing-your-ignition

or book is still avail used on different sites. recommend for anybody's technical library.