Cold spark plugs?

[eillob]

Does anybody know exactly what a cold plug does. I mean I've read about them. Zex sells there colder plugs I notice they look a lot like bosch plantinum plus+4s. Can you use a regular plug or are you gonna do yourself some dammage by not using a colder plug?

[parrish5o]

I'm not sure if this is what you mean by "cold" but I was told by the techs at Panhandle to use a plug one step cooler than what recomended by Canfield to compensate for the increased cylinder pressure of using N2O. They gave me the part# of the plugs I needed and everything seems to work fine so I have never researched it any further.

[eillob]

Yeah I keep hearing people say that you need to run colder plugs. Something with no electrode that sticks out. What qualifies as a cold plug and what manufacturers make them? I'll have to do more homework.

[MustangRoadRacer]

According to Champion spark plugs:
"high performance spark plugs are usually of a much colder heat range than standard automotive or street plugs. Colder heat ranges must be used in engines with increased cylinder pressures and temps and higher brake-specific power output. Racing engines are stressed to extreme limits and require a specially constructed spark plug to operate in that environment. The first area to investigate will be the type of shell needed. In order to gather this information you must know the thread diameter, length and seat type required by your cylinder head. Do not use a removed spark plug as a guide for determining proper shell dimensions. Failure to get accurate information in this area can result in decreased performance and damaged engines. The second step is to select a gap style that will maximize your performance based on your operating environment. Champion makes numerous electrode and gap configurations to meet the needs of all racing applications. The third step is to select the heat range that corresponds with the required shell and gap style. We recommend that you start your selection of heat range on the cold side of the available plugs and work your way up to a hotter design by reading the plug. Once a plug has been selected, it should be installed and run during practice with the motor "cut clean" to allow proper reading of the plugs. Remember, make only one change at a time. Do not make spark plug changes along with injection/carburetion or timing changes as this can result in misleading or inaccurate conclusions."

"The term "heat range" refers to the relative temperature of the core nose of a spark plug. The words "hot" or "cold," when used in referencing spark plugs, are often a source of confusion and misunderstanding, since normally a hot spark plug is used in a cold engine (low horsepower) and a cold plug in a hot engine (high horsepower). The terms actually refer to the heat rating or thermal characteristics of the plug; more specifically, the plug's ability to dissipate heat from its firing end into the engine cooling system. A cold plug transfers heat rapidly away from its firing end into the cooling system and is used to avoid core nose heat saturation where combustion chamber or cylinder head temperatures are relatively high. A hot spark plug has a much slower rate of heat transfer and is used to avoid fouling where combustion chamber or cylinder head temperatures are relatively low. The primary means of adjusting heat range are by varying the length of the core nose and the alloy material used in the electrodes. Hot plugs have a relatively long insulator nose with a long heat transfer path. Cold plugs have a much shorter insulator nose and thus, transfer heat more rapidly (see illustration; hot to cold - left to right). The heat range of a plug does not affect the power output of an engine. Rather, it allows the plug to function as designed for the duration of the racing event. In other words, once the correct heat range is found that prevents fouling and does not contribute to the pre-ignition or detonation, a change to a hotter or colder plug will not have a positive effect on engine performance. "

That should clear things up.

[MustangRoadRacer]

here's the picture.

[eillob]

Mustang road racer, thanks appreciate all the help. Thats a lot better answer than I got from the local speed shop.

[MustangRoadRacer]

the magic of google.com brotha.