NGK iridium spark plugs - Page 2

Luddite · 12-04-2020, 05:22 PM

Like Mr Gazza, I'm no expert in this field and agree that any information from the manufacturers themselves may not be wholly subjective as they have a vested interest and want you to buy their products.

For what it's worth, this diagram and explanation is from the Denso website.

https://www.denso.com/global/en/prod...condition.html

"The smaller the electrode the more concentrated the electric potential at the tip of the electrode and the stronger the electric field that affects required voltage and the lower the required voltage."

Although this information comes from a plug manufacture, I do believe that electrode size and shape does affect spark generation and Denso's diagram appears to be backed up by independent research.

https://docs.lib.purdue.edu/cgi/view..._access_theses

This is not specifically about spark plugs but it does show how different electrode shapes affect the voltage needed to create a spark across any given gap and I don't see why the findings shouldn't also be relevant to spark plug design.

Mr Gazza · 12-04-2020, 06:06 PM

Studying all at makes me feel I know even less!

So any theories on how the shirt buttons work? I've always wondered.

Luddite · 12-04-2020, 06:32 PM

Quote:

Originally Posted by Mr Gazza

So any theories on how the shirt buttons work? I've always wondered.

Sorry, Mr G, can't help you with the buttons, I'm still struggling with velcro!

Darren69 · 13-04-2020, 06:25 AM

Quote:

Originally Posted by Luddite

Sorry, Mr G, can't help you with the buttons, I'm still struggling with velcro!

Is it some crude sort of capacitor maybe?

13-04-2020, 07:21 AM

Gary,

In days gone by, you could buy a commercial Spark Booster which was simply an enclosed spark gap external to the motor. The theory appeared to be that once the voltage had built up enough to jump this significant gap, it would make small work of the plug gap itself! At the very least you'd imagine this would entail a slight delay of the spark, if not provoke breakdown of the insulation elsewhere. This is likely what your old-timer was doing. I never tried it myself cos it looked more like snake-oil!

Nick

13-04-2020, 07:23 AM

If you now google Spark Booster, all you get is ads for some sort of electronic guitar enhancement!

Mr Gazza · 13-04-2020, 09:04 AM

Thanks Nick. I do vaguely remember Spark Boosters. I think they had a clear cylinder in the middle so you could see the extra spark?

If the shirt button works as you say then a little retardation probably wouldn't hurt a big slow revving over loaded lorry. Can't help wondering about how a bonnet full of naked sparks went with an equally dilapidated fuel system??!

12-04-2020, 06:06 PM	#17
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,793	Studying all at makes me feel I know even less! So any theories on how the shirt buttons work? I've always wondered. __________________

13-04-2020, 09:04 AM	#22
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,793	Thanks Nick. I do vaguely remember Spark Boosters. I think they had a clear cylinder in the middle so you could see the extra spark? If the shirt button works as you say then a little retardation probably wouldn't hurt a big slow revving over loaded lorry. Can't help wondering about how a bonnet full of naked sparks went with an equally dilapidated fuel system??! __________________

12-04-2020, 05:22 PM	#16
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Like Mr Gazza, I'm no expert in this field and agree that any information from the manufacturers themselves may not be wholly subjective as they have a vested interest and want you to buy their products. For what it's worth, this diagram and explanation is from the Denso website. https://www.denso.com/global/en/prod...condition.html "The smaller the electrode the more concentrated the electric potential at the tip of the electrode and the stronger the electric field that affects required voltage and the lower the required voltage." Although this information comes from a plug manufacture, I do believe that electrode size and shape does affect spark generation and Denso's diagram appears to be backed up by independent research. https://docs.lib.purdue.edu/cgi/view..._access_theses This is not specifically about spark plugs but it does show how different electrode shapes affect the voltage needed to create a spark across any given gap and I don't see why the findings shouldn't also be relevant to spark plug design.

13-04-2020, 07:21 AM	#20
The Clockie Guest Posts: n/a	Gary, In days gone by, you could buy a commercial Spark Booster which was simply an enclosed spark gap external to the motor. The theory appeared to be that once the voltage had built up enough to jump this significant gap, it would make small work of the plug gap itself! At the very least you'd imagine this would entail a slight delay of the spark, if not provoke breakdown of the insulation elsewhere. This is likely what your old-timer was doing. I never tried it myself cos it looked more like snake-oil! Nick

13-04-2020, 07:23 AM	#21
The Clockie Guest Posts: n/a	If you now google Spark Booster, all you get is ads for some sort of electronic guitar enhancement!