The Spark Plug Story

[BrianHG]

Enjoy:

[mawyatt]

Interesting, a lot more complex than one might think

Best

[joeqsmith]

Tough to cover in 20mins but I thought it was a good overview.

• At 10:30, he mentions the surface discharge plug.  I had an old 2-stroke motorcycle that used these.  Cleaning them was a problem.
• HCCI has been around now for decades.  I'm surprised they make no mention of it.
• When talking about the timing, or the gap width, they never mention the effects of cylinder pressure. 
• When talking about detonation, I was surprised they did not mention Bosch's wideband sensor.   

At one point we were attempting to flow gas through the spark plug to help expand the ionized gas beyond the gap.

Their mention of using the plug as a sensor was used several years prior.  I worked on a gas range cook top that I used the igniter to detect if the flame was out and reignite.  Cooks were always looking for that simmer.   Me, I burn everything....

[langwadt]

3:00 as soon as the spark strikes the air ionizes and voltage drops drastically 

[coppercone2]

the spark plug gauge and the spark plug cleaner. i wonder how well those high end plated ones clean lol


 

[joeqsmith]

My pressure chamber using nitrogen.  The setup has various coils, wires and such.   I used this setup to get a feel for how good different boots sealed, dielectric grease and even tried adding a custom insulator.     

Plug2 shows the damage to the insulator once it breaks down.