Spark plug -NGK BR HSA- BR8HSA vendita calda online

Description

Spark plugs differ in the following things:

Thread diameter
The common threads are M10, M12 and M14. Classic vehicles usually have an M14 thread. 4-strokes and modern 2-strokes with fuel injection use the smaller plugs with M10 or M12.

Thread length
The common thread lengths are 19mm (long thread) and 12.7mm (short thread).

Heat value
The heat value is decisive for the thermal fatigue strength of the spark plug as well as its self-cleaning effect. A distinction is therefore made between so-called cold and hot spark plugs.
A cold plug is for engines that develop a very high combustion chamber temperature, usually these are engines that have a lot of power in relation to their displacement. A hot plug, on the other hand, is used in lightly loaded production engines. This type of plug quickly reaches a high temperature, which means that the soot on the plug burns off easily.
The temperature resistance is achieved by differently designed insulators. A cold plug can dissipate a lot of temperature via the cylinder head, but with a cold plug exactly this is strongly prevented. Heat rating has nothing to do with the strength or performance of a spark plug. A cold plug in a cold (weak) engine will oil or soot and can break without damaging the engine itself. A hot spark plug in a racing engine will burn up and damage it ,usually badly.
The heat value of a spark plug is not standardized. Each manufacturer has its own code.

• NGK from cold to hot = 10-9-8-7-6
• Bosch from cold to hot = 2-3-4-5-6
• DENSO from cold to hot = 37-34-31-27-24-22-20-16-14

Electrode material
Copper, platinum, silver or even iridium are used here.
Copper is the most common, followed by silver and platinum. Due to the high prices for the precious metals, the spark plugs are also correspondingly more expensive than their copper counterparts.
The material is ultimately almost only of interest for wear, only the extremely thin iridium electrodes (Ø=0.6mm) have a higher ignition voltage, the spread of the flame front in the combustion chamber is improved.

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