NGK 2-R6252K-105 Racing Spark Plug 2741

( Brand: Ngk ), ( Manufacturer Part Number: 2-R6252K-105 ), ( Part Type: Spark Plug )

Review NGK Racing Spark Plug

The **NGK 2-R6252K-105 Racing Spark Plug** (part number 2741) is a high-performance, precision-engineered ignition component designed to deliver unparalleled power, efficiency, and reliability in demanding racing and high-stress applications. Built with NGK s signature **Racing Series** technology, this spark plug features a **copper core electrode** encased in a durable **nickel alloy body**, ensuring exceptional heat dissipation and resistance to erosion critical factors for engines operating at extreme RPMs and under heavy loads. The **double-gap design** (0.7 mm primary gap and 0.4 mm secondary gap) optimizes ignition reliability, reducing misfires and enhancing combustion stability, even in high-compression or turbocharged setups. The **resistorless construction** eliminates radio interference, making it ideal for high-tech racing environments where clean signal transmission is essential. Engineered with a **fine-grain nickel alloy tip**, this plug resists fouling and wear, extending its lifespan while maintaining consistent performance across a wide range of operating conditions. Whether installed in a **drag race, circuit racing, or high-revving street engine**, the 2-R6252K-105 excels with its ability to handle intense heat and mechanical stress, ensuring a strong, consistent spark for maximum horsepower and torque. Its **threaded 14mm x 1.25mm** design and **19mm shell diameter** provide a secure fit in modern high-performance engines, while the **longer electrode projection** improves flame kernel formation, promoting faster combustion and better fuel efficiency. Built to NGK s rigorous standards, this plug is a trusted choice for racers and tuners seeking a balance of durability, performance, and precision ignition.

The **NGK 2-R6252K-105 Racing Spark Plug** (part of the **2741 series**) is a high-performance spark plug designed for racing and high-compression engines. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros**

1. **High Performance and Power Output**

The 2741 series is engineered for racing applications, featuring a **copper core electrode** and **iridium center electrode**, which allows for a **colder heat range** compared to standard plugs. This helps maximize combustion efficiency, improve throttle response, and increase horsepower in high-performance engines.

2. **Durability and Longevity**

The **double iridium tip** (on the 2-R6252K-105 variant) is highly resistant to wear, extending plug life significantly compared to standard copper or platinum plugs. This makes it suitable for **high-mileage racing applications** without frequent replacements.

3. **Optimal Heat Range for Racing Engines**

Racing engines often run at higher temperatures and compression ratios, which can cause premature fouling or pre-ignition in standard plugs. The **2741 series** is designed to handle these conditions, reducing the risk of **detonation** while maintaining consistent spark.

4. **Improved Fuel Efficiency and Combustion**

The precise gap and electrode design promote **cleaner, more complete combustion**, reducing fuel waste and improving efficiency beneficial for both drag racing and time-attack applications.

5. **Compatibility with High-Octane Fuels**

Since racing engines often use **high-octane fuels (100 octane)**, the 2741 series performs well without the risk of **knocking** that can occur with standard plugs in such conditions.

6. **Wide Thread Fitment**

NGK s **2741 series** is designed to fit a variety of **high-performance engines**, including those from **Ford, Chevy, Dodge, and Japanese manufacturers**, making it a versatile choice for tuners and racers.

7. **Resistance to Fouling and Deposits**

The **copper core** helps dissipate heat quickly, reducing carbon buildup and oil fouling common issues in high-RPM racing applications.

---

### **Cons**

1. **Higher Cost Compared to Standard Plugs**

Racing-grade spark plugs like the **2-R6252K-105** are significantly more expensive than **standard copper or platinum plugs**. The premium price reflects the **specialized materials and engineering** required for high-performance use.

2. **Requires Proper Gapping and Installation**

Since these plugs are designed for **high-compression, high-performance engines**, improper gapping (too wide or too narrow) can lead to **misfires, poor combustion, or even engine damage**. Racers must ensure correct gap settings (typically **0.028" to 0.035"**) and proper installation torque.

3. **Not Suitable for Every Engine**

While the **2741 series** works well in **high-performance and racing applications**, it may be **too cold** for **low-compression or street-tuned engines**. Using it in a **stock or mildly modified engine** could lead to **pre-ignition (knocking)** due to excessive heat retention.

4. **Limited Availability in Some Regions**

High-performance racing plugs are not as widely stocked as standard plugs, meaning they may require **special ordering** from performance parts suppliers rather than being available at every auto parts store.

5. **Potential for Over-Tuning Risks**

If an engine is **already heavily modified** (turbocharged, nitrous-injected, or with extreme compression ratios), the **2741 series** may still struggle with **extreme heat buildup**. In such cases, **even colder plugs (like the 2748 series)** might be necessary.

6. **Maintenance Dependency on Engine Condition**

If the engine has **oil leaks, carbon buildup, or poor combustion**, even a premium plug like this will **foul or misfire**. Regular **valve cleaning, carbon removal, and fuel system maintenance** are essential for optimal performance.

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### **Conclusion**

The **NGK 2-R6252K-105 Racing Spark Plug (2741 series)** is an **excellent choice for high-performance racing applications**, particularly in **drag racing, time-attack, and heavily modified engines**. Its **copper core, double iridium tip, and optimized heat range** make it one of the best options for maximizing power, reliability, and longevity in extreme conditions.

However, it is **not a plug for everyday street use** it is **too cold** for most stock or mildly modified engines and **too expensive** for casual drivers. It is best suited for **racers, tuners, and those running high-compression, forced-induction, or nitrous-enhanced engines**.

If you are **not in a racing environment** but want an upgrade for a **high-performance street car**, a **platinum or iridium plug with a slightly hotter range (like NGK s 2748 or 2749 series)** may be a better balance of performance and practicality.

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### **Recommendation**

You are running a **racing engine** (drag, time-attack, circle track, etc.).

Your engine has **high compression (11:1 or higher)** or is **forced-induction (turbo/supercharged)**.

You are using **high-octane fuel (100 octane)** and need **maximum power and reliability**.

You are willing to **gap and install them correctly** and maintain your engine properly.

You are using it in a **stock or mildly modified street car** (risk of knocking).

Your engine has **oil leaks, carbon buildup, or poor combustion** (plugs will foul quickly).

You are on a **tight budget** standard iridium or platinum plugs may suffice for street use.

You are unsure about **gapping and installation** incorrect use can cause misfires or damage.

- For **street performance cars**, consider **NGK 2748 (Iridium IX) or 2749 (Iridium IX Super)** they offer a balance of performance and practicality.

- For **extreme racing (high boost, nitrous, or extreme compression)**, look into **NGK 2748 or 2748R** (even colder).

- For **budget-conscious racers**, **Champion Racing or Denso Iridium plugs** are also strong alternatives.

The **NGK 2-R6252K-105 is a top-tier racing plug** that delivers **unmatched performance in the right applications**. However, it is **not a plug for casual drivers** it is a **specialized component for serious racers**. If you are in the market for one, ensure your engine is **properly tuned, maintained, and suited for high-performance use** to get the best results.

Details:

The NGK R6252K-105 Racing Spark Plug is engineered specifically to withstand the extreme heat and grueling conditions of high-performance racing environments. Brand NGK, Part Number 2-R6252K-105, Condition NEW, Notes/Other Racing spark plug; designed for extreme use. Its specialized design ensures consistent ignitable and durability under high-stress conditions. Trivalent metal plating for corrosion resistance.

2026 SLM Racing. Engineered for extreme racing heat and vibration. Key Features. Ensure proper torque specifications are followed during installation according to your engine manual.

Please verify fitment for your specific application before purchasing. Corrugated ribs to prevent flash over. Please verify fitment with your specific vehicle before purchasing. Solid copper core for superior heat dissipation.

The design incorporates cold-rolled threads to prevent damage during installation and removal, a trivalent metal plating that provides excellent anti-corrosion anti-seizing properties. This spark plug features a durable construction designed to maintain consistent ignition and performance under intense engine loads.

part #: 2r6252k105 prices

• $10.98-$49.39

specifications cyclesparkplugs:

• brand: Ngk
• mpn: 2-r6252k-105
• part type: Spark Plug

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• started: June 5, 2026
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• Motorcycle Scooter Parts Accessories > Electrical Ignition Components > Spark Plugs
• condition: New

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