Installed Denso Iridium Plugs
Apr 14, 2004, 01:06 PM
#31
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The main difference between the stock and a 1 step cooler than stock plug is the length that the center electrode protrudes past the threads. You will see as you go cooler and cooler on a plug, the center electrode and insulator are sunk further down into the plugs body. When the electrode protrudes further into the cylinder head it can retain heat from combustion and this hot electrode adds heat into the combustion process, which can in high cylinder pressures cause pre ignition. OEM engineers try to obtain a fine line between getting the right length on this, the longer the protrusion into the cylinder, the less likely the plug will get build up and eventual fouling. The additional heating of the electrode causes the spark plug to stay cleaner under normal driving. If you go too cool a plug the electrode doesn't get hot enough during normal (non spirited driving) to keep the electrode clean (fouling over time). You can clean a plug off like this for a little while, by making a few WOT runs, this cleans the electrode off.
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too. Too cool a plug and you may not get enough heat to keep them clean. Too hot a plug in a high horsepower motor can cause center electrode erosion.
Brian
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too. Too cool a plug and you may not get enough heat to keep them clean. Too hot a plug in a high horsepower motor can cause center electrode erosion.
Brian
Apr 14, 2004, 01:17 PM
#32
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Originally posted by TURBODAWG
The main difference between the stock and a 1 step cooler than stock plug is the length that the center electrode protrudes past the threads. You will see as you go cooler and cooler on a plug, the center electrode and insulator are sunk further down into the plugs body. When the electrode protrudes further into the cylinder head it can retain heat from combustion and this hot electrode adds heat into the combustion process, which can in high cylinder pressures cause pre ignition. OEM engineers try to obtain a fine line between getting the right length on this, the longer the protrusion into the cylinder, the less likely the plug will get build up and eventual fouling. The additional heating of the electrode causes the spark plug to stay cleaner under normal driving. If you go too cool a plug the electrode doesn't get hot enough during normal (non spirited driving) to keep the electrode clean (fouling over time). You can clean a plug off like this for a little while, by making a few WOT runs, this cleans the electrode off.
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too. Too cool a plug and you may not get enough heat to keep them clean. Too hot a plug in a high horsepower motor can cause center electrode erosion.
thanks for the explanation
Brian
The main difference between the stock and a 1 step cooler than stock plug is the length that the center electrode protrudes past the threads. You will see as you go cooler and cooler on a plug, the center electrode and insulator are sunk further down into the plugs body. When the electrode protrudes further into the cylinder head it can retain heat from combustion and this hot electrode adds heat into the combustion process, which can in high cylinder pressures cause pre ignition. OEM engineers try to obtain a fine line between getting the right length on this, the longer the protrusion into the cylinder, the less likely the plug will get build up and eventual fouling. The additional heating of the electrode causes the spark plug to stay cleaner under normal driving. If you go too cool a plug the electrode doesn't get hot enough during normal (non spirited driving) to keep the electrode clean (fouling over time). You can clean a plug off like this for a little while, by making a few WOT runs, this cleans the electrode off.
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too. Too cool a plug and you may not get enough heat to keep them clean. Too hot a plug in a high horsepower motor can cause center electrode erosion.
thanks for the explanation
Brian
Apr 14, 2004, 02:27 PM
#33
Originally posted by TURBODAWG
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too.
A cooler plug doesn't pull heat out so much as it keeps the hot electrode further away from the combustion. This keeps it slightly cooler as well too.
Jun 16, 2011, 06:56 PM
#35
ive been using the Denso IKH24's just received my second set. i started using them after i installed the BBK Full and Cams. i was told that these were the one step colder plug for the IX. they seem to be pretty good, although i never did a before and after log to see any differences
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