DCAWD.com

The operating temperature of a spark plug is the actual physical temperature at the tip of the spark plug within the running engine. This is determined by a number of factors, but primarily the actual temperature within the combustion chamber. There is no direct relationship between the actual operating temperature of the spark plug and spark voltage. However, the level of torque currently being produced by the engine will strongly influence spark plug operating temperature because the maximum temperature and pressure occurs when the engine is operating near peak torque output (torque and RPM directly determine the power output). The temperature of the insulator responds to the thermal conditions it is exposed to in the combustion chamber but not vice versa. If the tip of the spark plug is too hot it can cause pre-ignition leading to detonation/knocking and damage may occur. If it is too cold, electrically conductive deposits may form on the insulator causing a loss of spark energy or the actual shorting-out of the spark current.

A spark plug is said to be "hot" if it is a better heat insulator, keeping more heat in the tip of the spark plug. A spark plug is said to be "cold" if it can conduct more heat out of the spark plug tip and lower the tip's temperature. Whether a spark plug is "hot" or "cold" is known as the heat range of the spark plug. The heat range of a spark plug is typically specified as a number, with some manufacturers using ascending numbers for hotter plugs and others doing the opposite, using ascending numbers for colder plugs.

The heat range of a spark plug (i.e. in scientific terms its thermal conductivity characteristics) is affected by the construction of the spark plug: the types of materials used, the length of insulator and the surface area of the plug exposed within the combustion chamber. For normal use, the selection of a spark plug heat range is a balance between keeping the tip hot enough at idle to prevent fouling and cold enough at maximum power to prevent pre-ignition leading to engine knocking. By examining "hotter" and "cooler" spark plugs of the same manufacturer side by side, the principle involved can be very clearly seen; the cooler plugs have more substantial ceramic insulators filling the gap between the center electrode and the shell, effectively carrying off the heat, while the hotter plugs have less ceramic material, so that the tip is more isolated from the body of the plug and retains heat better.

Heat from the combustion chamber escapes through the exhaust gases, the side walls of the cylinder and the spark plug itself. The heat range of a spark plug has only a minute effect on combustion chamber and overall engine temperature. A cold plug will not materially cool down an engine's running temperature. (Too hot of a plug may, however, indirectly lead to a runaway pre-ignition condition that can increase engine temperature.) Rather, the main effect of a "hot" or "cold" plug is to affect the temperature of the tip of the spark plug.
It was common before the modern era of computerized fuel injection to specify at least a couple of different heat ranges for plugs for an automobile engine; a hotter plug for cars which were mostly driven mildly around the city, and a colder plug for sustained high speed highway use. This practice has, however, largely become obsolete now that cars' fuel/air mixtures and cylinder temperatures are maintained within a narrow range, for purposes of limiting emissions. Racing engines, however, still benefit from picking a proper plug heat range. Very old racing engines will sometimes have two sets of plugs, one just for starting and another to be installed once the engine is warmed up, for actually driving the car.

drwrx wrote:These are the ones I would recommend: NGK, IX iridium Part No. BKR6EIX or BKR7EIX
They are $7.83 each from http://www.sparkplugs.com.

Mr Kleen wrote:the BKR7EIX plugs are a step colder, correct? they're a buck more, but not a bad price.

Mr Kleen wrote:what's up with the Pulstar Pulse Plug BE-1? they're $24.98 EACH!

drwrx wrote:These are the ones I would recommend: NGK, IX iridium Part No. BKR6EIX or BKR7EIX
They are $7.83 each from http://www.sparkplugs.com.

drwrx wrote:

Mr Kleen wrote:

Mr Kleen wrote:what's up with the Pulstar Pulse Plug BE-1? they're $24.98 EACH!

There have been tests that indicate the Pulse Plugs do add power. Import Tuner got 6 whp out of a 4g63.
Is $100 worth 6 whp?

sparkplugs.com wrote: Pulstar Challenge!
What Is A Pulse Plug Anyway?
Pulstar Pulse Plugs incorporate a pulse circuit in their plugs that stores incoming electrical energy from the ignition system and releases it in a shorter, more powerful, pulse of energy. Pulstar plugs deliver up to 1,000,000 watts of peak power as compared to regular spark plugs that deliver only 50 watts of power. This powerful spark generates a much larger, more powerful spark at twice the speed of a spark plug, burning fuel more efficiently and increasing the rate of effective combustion. This translates to an increase in horse power and gas mileage.

Platinum and Iridium Pulse Plugs
Platinum and Iridium Fine Wire spark plugs have increased in popularity due to their durability and long life. Now Pulstar has incorporated this technology into their new lines of Platinum and Iridium pulse plugs. Your vehicle will receive the same great increase in horse power and gas mileage that traditional Copper Pulse Plugs provide, but with the long life Platinum and Iridium have to offer. These new precious metal pulse plugs come with a great new price! Only $9.95 for Pulstar Platinum Plugs and $12.95 for Pulstar Iridium Plugs!

Take The Pulstar Challenge!
We challenge you to try out Pulstar Pulse Plugs, 100% risk free! Pulstar has guaranteed that their pulse plugs will work for you, or return them for a full refund! Try Pulstar today! What do you have to lose?!
Visit our Pulstar dedicated site at www.PulstarPulsePlugs.com. and give Pulstar a try today!