The spark plug temperature remains too low and causes deposits to build up on the firing end; the deposits provide an electrical leakage path that gives rise to a reduction of spark. The spark plug temperature rises too high and induces abnormal combustion pre-ignition ; this leads to melting of the spark plug electrode that could cause problems such as piston seizure.
Importance of Heat Range. True for NGK, but some brands eg. Autolite have the heat ranges reversed. For them, a 9 would be hotter than an 8. Dunno why anyone would use Autolite in anything tbh haha Yes! That's why I wrote " Generally". Pretty sure using a hotter plug won't cause and increase in combustion temperature.
It's about plug life; the right temperature plug is not so hot that it melts the electrode and not so cold that it fouls it.
The only reason to go hotter is if you are fouling the plugs you are using. Was looking at the spark plug thread. Burning Methanol, HP engine. I started saving the NGK plugs. Not much difference, 2 Hemi heads! Awhile back "Rock Auto dot com" had closeout sale on the Autolites 's for 97 cents a piece. Two basic conditions for proper performance of a spark plug are given by sufficient electrical insulation between the center and ground electrodes, and heat transfer from the parts of the spark plug projected into the combustion chamber.
Both conditions are directly related. In order to ensure sufficient insulation between center and ground electrodes it is necessary, to keep the insulator tip the part of the insulator projecting into the engine area within an optimum temperature range. Insulator tip temperature is influenced by the proper choice of spark plug heat range.
One heat range changes the spark plug insulator tip temperature by about 75 - degree Celsius. To col d spark plug for a given engine. Suitable spark plug for a given engine. If the insulator tip temperature drops into the so-called deposit zone , combustion deposits carbon, non-combusted fuel, lubrication oil, impurities from the atmosphere start to form on the insulator tip surface.
A consequence of these combustion deposits on the insulator tip is reduction in electrical insulation resistance accompanied by failing ignitions and after a certain period of time even by a failure of the spark plug performance.
In this temperature range, no new deposits are formed and those existing will be burnt. The spark plug operates in an optimum manner. Too high temperature of the insulator tip is undesirable. Which NGK plug is hotter? What is a hotter plug?
How do I know if I need a colder spark plug? Why does one spark plug get colder? Why would you run a hotter spark plug? What will happen if the spark plug gap is too large or too small?
0コメント