Hmmm...

As much as I do believe a spark plug is just a spark plug, I think that buying 'better' iridium or platinum 'plugs is a good move.

Take what I say with a pinch of salt, as I don't know about the knock detection system in H-D's, and you're spending your money on your own bikes. But...

A better spark plug will be more resistant to high temperatures, and less prone to breaking down. If you've got an over-heating, or pinging / pinking engine, this is absolutely not the way to keep it running. But, a harder wearing, higher heat-range spark plug can only be a good thing?

And to those who worry so severely about the knock detection system being thrown out-of-kilter by an after-market spark plug, I personally have my doubts. However, surely the best cure for that is prevention - by getting a decent tune on a rolling road, you're bike will run better, have more power, use less fuel, and be MUCH less likely to suffer early failure to detonation. A well spent Ł300, in my opinion at least. Everyone knows that the stock tunes in cars and bikes are now mega-lean out of the factory, so why not get it adjusted?

 

Good points but a couple of thoughts...

But is it a better spark plug? Because it cost more and is made of exotic materials and is hyped to death by the maker?

Harleys engines are basic things, not high revving, tuned-to-death sports machines. The phrase "putting cream on dog ****" springs to mind.

Apart from that one often-linked YouTube video of the tech finding 2 HP extra power with expensive plugs on a Harley (with no evidence of how reliable a source the video is) there is zero evidence of any improvement with any other than stock plugs.

The only time I have ever seen an improvement with non-stock plugs on a Harley is when the stock plugs were old and knackered. Replacing with new stock plugs would have made the same improvement.

Its not about running a knocking engine or not. Its about transient knocks that occur occasionally due to a tune with the timing set for performance and also due to the fuel available now.

If you tuned the bike so it never ever knocked you would be sacrificing a lot of performance. By tuning the timing more aggressively and having an anti-knock system that detects occasional knock events and reduces timing for a couple of revs to prevent damage you have the best of both worlds.

 

Your spark plug wires will affect the anti-knock system in the Delphi equipped bikes, probably way before any of the plugs will.

That being said, a good basic plug is all these engines need. Now if you're going to raise your compression significantly, you may want to take a look at higher voltage coils and then plated plugs (platinum/iridium).

The Delphi anti knock system measures the air gap of the plug. When detonation occurs, whether on time or before it should, the air/fuel mixture becomes ionized during flame travel. Ionized "air" has a different resistance than regular air... ie- lightning strikes.

Plug 'sparks; have been known to have been 'blown out' by higher compression engines, and so high voltage coils were introduced along with plated plugs. Take a look at plugs produced for friggin years by Accel... single electrode - simple plug.. plated to handle the extra spark, and the ability of that higher voltage/temperature spark to remove metal on standard plugs.

Everybody gets so enamored with their expensive "Ultra-gap 500s". They just don't live up to the hype.

 

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“The spark plugs in your motorcycle & car are just as feeble as the ones in your lawnmower. Each provide a measly 50-watt spark. For over 100 years, conventional wisdom assumed 50 watts was sufficient to efficiently ignite fuel. But, the Pulstar Pulse Plug is proving conventional wisdom wrong.”
PulstarŽ is the first capacitor-enhanced spark plug. The drop-in replacement for spark plugs uses the capacitor to store, then discharge the ignition’s electrical power in a powerful pulse.
The Pulse Plug

The high power of the PulstarŽ Pulse Plug will not damage an engine because the high power event lasts only for 2 microseconds (billionths of a second). This very brief moment is enough to ignite the fuel in the cylinder, but too brief to overheat the combustion chamber or metal engine components. So it will neither harm your engine nor void your manufacturer’s warranty.
PulstarŽ pulse plugs look like spark plugs because they were designed to fit into the same hole in your engine. But, internally, PulstarŽ is very different, incorporating a pulse circuit no other plug has. This is why we call PulstarŽ a “pulse plug” and not a “spark plug”.
How Pulse Plugs Work

Pulse plugs incorporate a pulse circuit, which stores incoming electrical energy from the ignition system and releases the stored energy in a powerful pulse of power. Instead of 50 watts of peak power typical of all spark plugs, pulse plugs deliver up to 1 million watts of peak power.
Spark plugs waste energy by heating ignition components before the spark occurs. Pulse plugs capture wasted energy with a pulse circuit and then release the captured energy into and beyond the spark gap. When the ignition power overcomes the resistance in the spark gap, the pulse circuit discharges all of its accumulated power – 1 million watts – in 2 billionths of a second!
What Makes It A Pulse Plug?

The Pulse Circuit: This is what separates a pulse plug from a normal plug. Here, the energy is stored to be released into the gap once breakdown voltage is achieved by the ignition system. A typical plug has only the resistor, then a conductor which continues to the center electrode.
How Is A Spark Generated?

When the ignition event in an engine occurs, what happens in the ignition system depends on the type of ignition system present.
Inductive ignition system:
In an inductive ignition system the primary side of the coil is always energized at 12v until it’s disconnected. When the primary is disconnected, the magnetic field on the primary collapses and induces a 30,000v charge on the secondary coil producing the spark between the gap of the plug.
Capacitive Discharge Ignition:
In a CDI(Capacitive Discharge Ignition) system the signal is sent to the CDI circuit which sends a short, high-voltage pulse to the CDI ignition coil. The CDI ignition coil is basically a transformer taking the 250v input voltage and steping it up to around 40,000v very rapidly.
In either case, a high voltage charge is produced creating the spark to ignite the fuel.
The breakdown voltage required to cross the gap in the engine depends on a multitude of factors such as air temperature, air pressure and fuel saturation. Assuming normal atmosphere the breakdown voltage required for a typical .044″ plug gap and compression pressure of 160psi is around 25kv. That is equivalent to a typical engine usually at full throttle. Additionally, when the engine is at part throttle the voltage demand decreases significantly.
When the plug gap reaches its breakdown voltage requirements a plasma stream is formed from the center electrode to the ground strap on the plug. This plasma stream has zero resistance and drains the available power from the pulse circuit in about 2 microseconds. After this the normal resident stage of the spark continues until the coils have discharged and the process starts again.
The breakdown of the gap in a plug will cause electromagnetic and radio frequency interference.
An example of this is found in old “spark-gap” Morse code transmitters which relied on this interference for transmission. In present day, interference from those resistors would cause havoc with modern electronic ignition and fuel injection computers. Radio frequency interference would also be present and very noticable when trying to listen to a station.
Standard Spark Plugs have resistors inside the neck to help reduce interference with the additional resistance provided by the plug wires connecting the engine to the plugs.
PulstarŽ Pulse Plugs also provide insulation from interference. However, the insulation is located before the pulse circuit providing the stored energy an open pathway to freely discharge across the gap.
What does this mean in the engine?

PulstarŽ Pulse plugs take advantage of the charge / discharge cycle by storing energy on the voltage rise into its capacitor and releasing it very quickly when the breakdown of the gap happens. Instead of a typical spark of 25kv / .05amps, the pulse plug can, for around 2 microseconds, put 50 amps across the gap. Timing is unaffected since the gaps are usually set equal to or less than your normal spark plug settings keeping the spark voltage and length the same.

 

[quote=IncognitoProducts;10373444]Check out my website http://pulstar-incognitoproducts.com

Looks interesting, is there a discount for forum members?

Bocifus

 

Please check out my website http://pulstar-incognitoproducts.com

•  
  • Gain up to 12% more horsepower (very cost effective)
  • Gain up to 10% improved MPG (will pay for themselves in better fuel millage)
  • PulstarŽ Technology burns fuel 60% quicker, than ANY Spark-plug on the market today
  • 1 to 1 replacement with no risk of harm to your engine
  • 30-day money back guarantee
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PulstarŽ "Power Sports Series": Released November 2010 Expected lifespan: 75,000-100,000 miles Warranty: 2-year warranty PulstarŽ "Automotive Series": Released June 2006 Expected lifespan: 75,000-100,000 miles Warranty: Lifetime warranty

PulstarŽ Pulse Plugs… NOT a new idea….

The first patent for a Spark-Plug with an internal capacitor was filed in the early 1900′s. Sadly it took almost 100 years for technology to catch up, and turn the idea into a reality. After over 20 years of research, development, and extensive testing, the first ground breaking product Direct Hit came to market in 1994. The PulstarŽ pulse Plug was released in June of 2006. As a direct replacement part, for the the traditional Spark-Plug. A pulse Plug is not a Spark-Plug. PulstarŽ Pulse Plugs are the first technological advancement in Spark-Plug design in almost 100 years. Based on the proven science of Pulsed Power derived from Electrodynamics with the close cooperation of Sandia National Laboratories. How A Pulse Plug Works

Pulse Plugs feature a unique capacitor-based circuit which captures energy normally wasted by spark plugs and generates a spark with 20,000 times greater spark energy at the spark gap than any spark plug on the market today. PulstarŽ plugs may look similar to spark plugs on the outside, but the similarities end there. Inside, the







PulstarŽ Pulse Plugs are the first technological advancement in Spark-Plug design in almost 100 years. Based on the proven science of Pulsed Power derived from Electrodynamics with the close cooperation of Sandia National Laboratories. How A Pulse Plug Works

Pulse Plugs feature a unique capacitor-based circuit which captures energy normally wasted by spark plugs and generates a spark with 20,000 times greater spark energy at the spark gap than any spark plug on the market today. PulstarŽ plugs may look similar to spark plugs on the outside, but the similarities end there. Inside, the technological advances of PulstarŽ are evident.

 

[quote=Bocifus;10373542]If you e-mail me directly at http://incognitoproducts@yahoo.com (instead of ordering on line). I will give all Forum members free shipping anywhere in the USA. I will process you order and ship the same day (over the phone). I am going to have my web designer set up a promo code for Forum members. Check out the video at the bottom of Harley Davidson page to see the larger spark surface area.