NGK R5671A-10-6239 Racing Spark Plug 6239 - One-Piece Type

【NGK R5671A-10-6239 Racing Spark Plug 6239 Integrated Type】
■Product Description
For race or tuned engines!
NGK racing spark plugs are special spark plugs for those who participate in races or circuit driving, or those who have increased their engine output through tuning. Choose the optimal racing plug for your car and aim for the best performance.

Specifications
The firing end of a spark plug is exposed to the combustion chamber, repeatedly absorbing heat from combustion gases and radiating it to the engine. The heat range indicates the degree of balance between heat absorption and heat radiation (of the spark plug's firing end). The temperature of a spark plug is determined by the balance between the amount of heat absorbed and radiated, and it is necessary to select a heat range that maintains this balance, allowing the spark plug to operate normally.
●Hot Type and Cold Type
Spark plugs that readily absorb heat and whose firing end tends to burn are called hot types (low heat range), while those that are less prone to absorbing heat and whose firing end is less likely to burn are called cold types (high heat range). The hot type on the left has a long insulator and a large surface area for the insulator to absorb heat, which increases the spark plug's own temperature. The cold type on the right is the opposite, making it harder for the temperature to rise.
●Heat range is too low (Hot type)
The spark plug's temperature rises too high, inducing abnormal combustion (pre-ignition), which can cause electrode melting and even piston seizure.
●Heat range is too high (Cold type)
The spark plug's temperature does not rise easily, carbon accumulates on the firing end, allowing electricity to escape, and the spark stops firing.
●About the firing end shape
The shape of a racing spark plug's firing end must be selected according to the degree of tuning and driving conditions. Generally, types where the firing end protrudes into the combustion chamber offer superior ignition performance. However, they are more susceptible to high-temperature combustion gases, and their longer outer electrode can lead to thermal or mechanical problems. High-performance, high-output engines tend to have higher temperatures in the combustion chamber and greater engine vibration. Therefore, as tuning progresses, it becomes increasingly necessary to select a firing end shape with a shorter outer electrode that is less exposed to combustion gases.

■Notes on images
*Images are for illustration purposes only. Includes products with different sizes and colors. Product designs and specifications are subject to change without notice. Please be aware.

■Precautions
*The heat range and firing end shape of racing spark plugs must be selected according to the degree of engine tuning and driving conditions, so please make your selection at your own discretion and responsibility.
*We will not be held responsible for any engine or spark plug problems that may arise as a result.