Originally posted by Koolvin
what's a heat range cooler?
LOL - Spark plugs are catagorised into "heat ranges"
The heat range of a spark plug is its ability to dissipate heat from the combustion chamber to the cylinder head. The heat range, of a spark plug depends primarily on the length of the insulator nose. The heat from the combustion is transferred from the insulator nose through the center electrode to the plug housing, and from there it goes to the cylinder head
During the combustion process the tips of the spark plugs are heated until they glow. This heat must travel from the tip through the shell and ultimately into the water jacket of the cooling system before the next compression stroke. If the tip is still glowing when the piston comes up with fuel - you get pre igintion or pinking
therefore a "cold" plug has a shorter insulator nose, which minimizes the amount of surface area exposed to the combustion gases and therefore the heat absorbed
Most turbo applications use this type of plug because of the tremendous heat generated by the turbo. A colder plug can also minimize the risk of pre-ignition and detonation, however if the plug is to cold there is risk of fouling during extended periods of idling and low-speed "round town" type operation.
Spark plugs are not just spark generators - and their selection can be crucial in getting a car to run nicely.
So your car will be running "A heat range cooler"
Mark
Phew !
'> Either NGK, Champion or Bosch. I think Champion are OE on most mercs but NGK are regarded by many as the best, wont be anywhere near £60 with vat and delivery.
