NGK BP6ESZ Spark Plug – NGK Stock No. 7639
A dependable, non-resistor spark plug for many older petrol engines and performance builds that specify a projected tip. It uses a copper core and nickel alloy electrodes for stable ignition, good cold starts, and consistent performance.
The projected insulator helps place the spark closer to the fuel-air mix. This can improve throttle response and combustion efficiency in engines designed for this style of plug.
Important: This is a non-resistor plug. It suits ignition systems that specify non-resistor plugs. For many modern, ECU-controlled vehicles, a resistor type is recommended to reduce electrical interference.
Why choose it
- Reliable spark and stable idle
- Good cold starting and drivability
- Durable nickel ground electrode with copper core for heat control
| Part Number | BP6ESZ |
|---|---|
| NGK Stock Number | 7639 |
| GTIN | 87295176399 |
| Category | 686 – Spark Plug |
| Thread Size | M14 x 1.25 |
| Reach (thread length) | 19 mm |
| Hex Size | 20.8 mm (13/16 in) |
| Seat Type | Gasket |
| Heat Range | 6 (NGK scale) |
| Resistor | No (non-resistor) |
| Tip Projection | Projected insulator |
| Centre Electrode | Copper core, nickel alloy |
| Ground Electrode | Standard, nickel alloy |
| Factory Gap | 0.8 mm (check and set to vehicle spec) |
| Terminal | Supplied with terminal nut |
Fitment guidance
This plug type is commonly used on many classic petrol engines, motorcycles, and small performance applications that require a 14 mm thread, 19 mm reach, projected tip, and non-resistor design. Use the site’s vehicle lookup to confirm fitment, or check the Vehicle Fitment tab for full details.
Installation tips: Always match heat range and gap to the engine spec. Torque to the manufacturer’s value on a cold engine. Apply a new gasket and avoid over-tightening.
The price displayed is for a single plug, please add the desired amount to your basket.


