uhu, hitte afvoeren waren we het toch al over eens...? Dat de isolator tevens de werking heeft van koeling voor de bougie zelf...
even om terug te komen waar het om gaat...
Fuel Type / Quality
Low quality and/or low octane fuel can cause knock which will elevate cylinder temperatures. The increased cylinder temperature will cause the temperature of the combustion chamber components (spark plug, valves, piston, etc.) to rise, and will lead to pre-ignition if the knock is uncontrolled.
When using an ethanol blend fuel with high ethanol content in high performance applications, a colder heat range may be necessary. The spark timing can be advanced further because ethanol blend fuel has a higher resistance to knock (higher octane). Due to the decreased knock, there will be less audible “warning” from knock before the spark plug overheats and pre-ignites.
Some types of fuel additives in lower quality fuels can cause spark plug deposits that can lead to misfires, pre-ignition, etc.
Ignition Timing
Advancing ignition timing by 10° will cause the spark plug tip temperature to increase by approximately 70° to 100°C.
A colder heat range spark plug may be necessary if the ignition timing has been advanced to near the knock level. Higher cylinder temperatures near the knock level will bring the spark plug firing end temperature closer to the pre-ignition range.
Compression Ratio
Significantly increasing the static/dynamic compression ratio will increase cylinder pressures and the octane requirement of the engine. Knock may occur more easily. If the engine is operated near the knock level, a colder heat range spark plug may be necessary due to the resulting increased cylinder temperatures.
Forced Induction (Turbocharging, Supercharging)
A colder heat range spark plug may be necessary due to the increased cylinder temperature as boost pressure (manifold pressure) and subsequent cylinder pressure and temperature increase.
na aanpassing van een factor, bougie graad veranderen om de optimum temperatuur van de verbanding te behouden. Bougie heeft degelijk effect op de verbranding, en welke vonk er wordt gegeven... waar het hele verhaal om draait is, dat de bougie kouder moet zijn dan de vonk die er wordt geleverd omdat de bougie anders voor ongecoördineerde ontbranding zorgt...
again, samenhangend geheel...