Spark Plugs [Archive] - 1130cc.com: The #1 Harley Davidson V-Rod Forum

: Spark Plugs


ctvrod
02-21-2004, 06:54 AM
:ride:
Spark Plugs:
Have any of you fellow V-Roders changed you spark plugs to something other than HD? Over the years in my cars have changed to a platinum plug with great success, mileage and performance, of course most if not all of the new cars now come with a platinum plug. I see that NGK has an iridium plug that replaces the HD plug in our bikes; maybe some of the fellows that race could provide some input. Thanks

danafwelch
02-21-2004, 08:16 AM
:ride:
Spark Plugs:
Have any of you fellow V-Roders changed you spark plugs to something other than HD? Over the years in my cars have changed to a platinum plug with great success, mileage and performance, of course most if not all of the new cars now come with a platinum plug. I see that NGK has an iridium plug that replaces the HD plug in our bikes; maybe some of the fellows that race could provide some input. Thanks

I'm about ready to do my 5K and will replace the plugs with the stock OEM plugs from HDI. I tried the $17 iridium plugs in other bikes and went back to the standard type plug as the iridium's fouled when used in fuel injected bikes with ECM controls, stock or tweaked. The platinum plugs will simply last longer (that's what the platinum coating does) but you'll likely not feel the difference when riding with the iridium or platinum plug over the stock HDI plugs.

mjw930
02-21-2004, 08:29 AM
Check out this thread:
http://www.v-rodforums.com/forums/showthread.php?t=2201

Super Kaz
02-21-2004, 08:32 AM
I race with Nitrous Oxide so I needed to go a step or two Colder on the Heat range.Well if your tune up is of it don't matter what fu(kin plug is in it it's gonna hurt $hit! :yak: So my new theory is get a Good Tune Up and what Plug you have won't make that big a difference.Have the Wrong Tune Up and the Right Plug and your SCREWED! :( :tmbsdow:

jcolodny
02-21-2004, 09:20 AM
Is the part number you found for the NGK Iridium plug that replaces the stock plug: "KR8AI"

Super Kaz
02-21-2004, 10:41 AM
No it
2641
DCPR9E
:kaz:

jcolodny
02-21-2004, 01:14 PM
Based on what Mark supplied as the parameters for the plug, using "NGK guide", this is what I came up with:

(note for "8" heat range)
Iridium plug: KR8AI (stock number 5477)
Standard plug: DCPR8E (stock number 4339)

(note for "9" heat range)
Racing plug: R2525-9 (stock number 4735)

I just wanted to verify that I came up with the right part number for the Iridium plug KR8AI (not the standard plug). This appears to be a different number from what has been discussed.

thanks, John.

mjw930
02-21-2004, 01:18 PM
That sounds right.

jcolodny
02-21-2004, 01:22 PM
Mark...have you tried different plugs with your dyno runs?

Vinny
02-21-2004, 08:34 PM
What is so special about this 'iridium' plug.

mjw930
02-21-2004, 11:03 PM
John,

No, I haven't and I don't think they would show anything considering all the variables involved in a chassis dyno.

Vinny,

In theory the super small surface area you can get away with using iridium significantly reduces the heat sink properties of the electrode allowing more energy to be transfered to the spark. The down side is they are very fragile plugs. I know that I can't use any of the current fine wire tipped plugs in my Porsche, it will eat them like candy under boost. For the difference in price I think the performance gain wouldn't be worth it. Also, unless the combustion chamber is specifically designed for these hybrid plugs there's the chance that the will self destruct.

jcolodny
02-21-2004, 11:13 PM
From NGK.com & ngksparkplugs.com

Iridium

Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200(=F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, platinum had been favored for long life or performance spark plugs due to its high melting point, also the technology did not exist to machine and bond iridium on a spark plug electrode(at least in a cost effective manner). Iridium industrial spark plugs have been around for years, but still sells for over a hundred dollars per plug. Just now is the technology available to effectively use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium allows NGK to manufacture there iridium ultra-fine wire center electrode to 0.7mm. One of the finest firing points in the industry! (Thus far there has been no problems reported regarding use of iridium plugs with nitrous oxide.)

Iridium Spark Plugs

Iridium is a precious, silver-white metal and one of the densest materials found on earth. The natural properties of Iridium offered NGK the opportunity to create one of the world's finest spark plugs. The result are spark plugs that require less voltage to spark, burns fuel more efficiently, sparks at leaner air/fuel mixtures, and delivers higher horsepower and better gas mileage.

NGK offers two choices of this precious metal plug:

The Iridium - A high quality iridium plug installed as original equipment (OE) in the automotive industry since 1994, and the new Iridium IX® - The ultimate evolution of a performance spark plug.

http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/index.asp?nav=31200&country=US

Q: How much of a performance improvement can I expect from changing plugs?

A: A common misconception is that changing spark plugs will result in a large power increase. In most cases, removing even seriously worn out spark plugs will only result in very modest power gains, typically about 1-2% of total engine output. This could be even less for computer-controlled vehicles, primarily because most newer vehicles have more powerful ignition systems and the vehicle's computer can make adjustments so that vehicle operation seems smoother and more seamless.

Many people think that simply supplying more spark to the firing tip can and will combust more fuel. What they don't understand is that most newer cars' engines are so efficient that they are already burning all of the available fuel. Simply adding more spark voltage can't burn more fuel because there is no more fuel to burn.

When a stock or near-stock engine is given a fresh set of spark plugs, peak efficiency is restored. The power gains that come from this restored state of tune are usually minimal. Any company that tells you that their spark plug will provide significant gains in power in a stock or near-stock engine is making blanket statements that may not be supportable.

jcolodny
02-21-2004, 11:20 PM
I think between what Mark, Kaz, and ngksparkplugs.com says, there isn't much to be gained by using higher performace plugs unless a number of engine mods have been done.

Vinny
02-21-2004, 11:30 PM
I was curious,I wasn't planning on getting them.They sound a little to much for street use.Not worth it.

ctvrod
03-20-2004, 05:28 PM
:ride:

Searching the Net I found the following, for our 10R12A spark plug.
Denso # xu24epru I think that this an iridium plug.
Autolite # 4162 regular type plug.
Champion # RA8HC and #RA4HC I am guessing different heat ranges between the two.
Bosch #7700 (XR2CS) this is a silver tip plug, at this time there is not a platinum offering.
NGK has several regular types in different heat ranges in addition to the following.
NGK # IXU24 “Power” iridium.
NGK # VXU24 “Tough” iridium.

Just FYI, Wayne

HawgDoc
04-12-2004, 11:04 PM
Harley is using the V-Rod sparkplug as a sensor, to measure combustion completeness thru ion levels. I would be cautious about substituting other than factory plugs as it may affect the 'closed-loop' capabilities of the system. ( http://www.mecel.se/technologies/ionsense/default.htm )
And please..... dont ever fall for the 'multiple-ground-point' sparkplugs... two, three, four, six or TWENTY..... dont matter.

Super Kaz
04-14-2004, 11:03 AM
Harley is using the V-Rod sparkplug as a sensor, to measure combustion completeness thru ion levels. I would be cautious about substituting other than factory plugs as it may affect the 'closed-loop' capabilities of the system. ( http://www.mecel.se/technologies/ionsense/default.htm )
And please..... dont ever fall for the 'multiple-ground-point' sparkplugs... two, three, four, six or TWENTY..... dont matter.
what about racing aplications?we disable the knock sensor anyways because the amount of Nitrous I run was giving it Fits! :twisted:

0rest 0har
04-24-2004, 10:24 PM
Hawg Doc,

One of the long time hawg docs at my local dealer was telling me that the ion sense in fact closes the loop on combustion in a way similar to the O2 sensor fuel injection systems. He claims that the EFI is actually a closed loop system, and is smart enough not to allow the engine to run lean.

Is this a capability that they designed into the Delphi EFI, or do they just use it as a device that retards timing when the ion levels trend out of spec? Do you know any details on this that you can share with us? I'm very curious to learn about how HD is applying this technology...

Thanks

mjw930
04-25-2004, 09:09 AM
It's not closed loop. The ion sensor replaces the knock sensor. It's more accurate in our applications because of the inherent noise in a v-twin (it confuses the knock sensors). It's only used to retard timing, it has no effect on fuel delivery.

Your mechanic is wrong.

0rest 0har
04-30-2004, 10:41 PM
Thanks Mark. He was insistent, but not very convincing...

VrodG
04-30-2004, 11:21 PM
How about indexing the plugs, does the head...valve layout warrent this?

HawgDoc
05-03-2004, 08:57 AM
KAZ ..... what knock sensor?

OHAR .... similar, is not THE SAME. let's say it's a SEMI closed loop (as MJW explained)

Super Kaz
05-03-2004, 09:18 AM
KAZ ..... what knock sensor?

OHAR .... similar, is not THE SAME. let's say it's a SEMI closed loop (as MJW explained)
With THE KNOCK Control Sensor enabled.It would pull out to much Timing when the Nitrous Activated so with the RT you can just turn it off. :diablo:
Come on DOC you should Know This! :rolleyes:

garyjackel1
03-29-2012, 12:29 PM
what replacement plug is best suited for a harley davidson 2003 v rod

stever975
03-29-2012, 01:24 PM
what replacement plug is best suited for a harley davidson 2003 v rodEither the OEM spark plug: HD P/N 32335-04 (10R12A) or an NGK DCPR8E (Stock #: 4179). The plug gap on the NGK plugs come as 0.040" and should be reset to 0.035". If you use the OEM plugs the gap should be checked on those also.

DC1ESQ
03-31-2012, 08:12 AM
what replacement plug is best suited for a harley davidson 2003 v rod

8 year old revival! lol

Either the OEM spark plug: HD P/N 32335-04 (10R12A) or an NGK DCPR8E (Stock #: 4179). The plug gap on the NGK plugs come as 0.040" and should be reset to 0.035". If you use the OEM plugs the gap should be checked on those also.

i always run NGK's in everything! Steve yours were .040?? my NGK's actually came at a 0.30 lol

stever975
04-02-2012, 06:18 AM
...yours were .040?? my NGK's actually came at a 0.30 ...Good reason to always check and set gap to spec.

garyjackel1
04-03-2012, 08:23 AM
Has anyone tried the E 3 spark plug yet in there 2003 v rod

stever975
04-03-2012, 09:40 AM
Has anyone tried the E 3 spark plug yet in there 2003 v rodNot a good idea for any of the HD bikes with Delphi ECMs. These ECMs have an "ion sense" knock detector where the spark plug gap is a critical component. Multi-gap and surface gap plugs likely have an ionization behavior that would "confuse" the knock detection circuitry. Here's a write-up that explains the "ion sense" circuitry (http://www.1130cc.com/forums/attachment.php?attachmentid=157204&d=1284636336).

Nas3car
04-08-2012, 05:05 PM
How about indexing the plugs, does the head...valve layout warrent this?

8 years later

No it dose not. Indexing though in theroy is for more power, in truth it was for high dome pistons in a wedge head. It was to keep the side electrode from hitting the piston at high RPM and getting knocked shut. Normally we would place the side electrode between 10 and 2 o'clock, sometimes it had to be closer to 12 o'clock. Also when installing the spark plugs in said motor the pistons should not be at TDC. This may also close the gap durring installation. On our Pentroof or Cosworth design head indesing wull have little value. THink about this for a second. If the plug fires at 35degrees BTDC you are already compressing the mixture, by that poinit you may be at 7:1 or more well maybe not that high with our compression but the intake charge is already done,so the idea that intake charge is being blocked is mute. THe spark plug is in the mix and it will fire. Like I said before if you have Piston to plug clearance then it makes a difference.:hidesbeh: