🔥 NGK 5820 R5671A-10 Racing Spark Plug – High Performance Ignition

The NGK 5820 (R5671A-10) is a cold heat range racing spark plug engineered for high-output, modified, and competition engines. Designed to withstand extreme cylinder pressures and temperatures, this plug is commonly used in turbocharged, supercharged, nitrous, and high-compression performance builds.

This is NOT a standard OEM replacement plug. It is intended for performance and racing applications only.

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⚙️ Key Specifications

• Brand: NGK

• Manufacturer Part Number: 5820

• NGK Part Number: R5671A-10

• Thread Size: M14 × 1.25

• Reach: 0.750 in (19mm)

• Seat Type: Gasket

• Heat Range: 10 (Cold)

• Plug Type: Racing / Performance

• Fitment: Universal (engine-specific, not vehicle-specific)

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🏁 Common Performance Applications

Used in high-performance and racing engines including:

• GM LS-based V8 engines (LS1, LS2, LS3, LS6, LS7, LQ4, LQ9)

• Ford Modular & Coyote V8 builds (4.6L, 5.4L, 5.0L)

• Mopar Hemi performance engines (5.7L, 6.1L, 6.4L)

• Drag racing, street/strip, track, marine, and custom builds

✔ Ideal for:

• Turbocharged engines

• Supercharged engines

• Nitrous oxide applications

• High-compression race engines

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⚠️ Important Fitment Notice (Please Read)

• This spark plug does NOT replace OEM plugs by vehicle year/make/model

• Compatibility depends on engine design, tuning, and required heat range

• Buyer is responsible for verifying correct application

If your engine requires an M14 × 1.25, 19mm reach, gasket-seat, cold heat range plug, this plug may be suitable.

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📦 What’s Included

• Quantity: 4

• Brand new, genuine NGK spark plug(s)

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🔍 Why Buy NGK Racing Plugs?

NGK is a global leader in ignition technology, trusted in professional motorsports for:

• Consistent spark under extreme conditions

• Resistance to detonation and pre-ignition

• Proven durability in high-RPM environments

⚠️ COMPATIBILITY & FITMENT DISCLAIMER – PLEASE READ

This item is a high-performance / racing spark plug and is NOT a direct OEM replacement for any specific year, make, or model vehicle.

Vehicle compatibility CANNOT be determined by year/make/model alone. Fitment depends on:

• Engine design

• Required thread size, reach, and seat type

• Heat range requirements

• Engine modifications and tuning

Buyer is fully responsible for verifying correct application before purchase.

This spark plug is intended for engines that require:

• M14 × 1.25 thread

• 0.750 in (19mm) reach

• Gasket seat

• Cold heat range (NGK 10)

⚠️ Not recommended for stock or daily-driven vehicles unless specifically advised by a professional engine builder or tuner.

Returns will not be accepted for:

• Incorrect fitment

• Buyer error

• Ordering based on vehicle year/make/model assumptions