The NGK BPR6ES spark plug features an M14 x 1.25 thread. This metric thread specification is crucial for ensuring proper fitment and sealing within an engine's cylinder head.
Understanding Spark Plug Thread Specifications
Spark plugs are precision components, and their thread specifications are vital for correct installation and optimal engine performance. The details for the NGK BPR6ES spark plug are as follows:
| Specification | Detail |
|---|---|
| Thread Size | M14 x 1.25 |
| Thread Length | 19.0 mm |
| Spanner Size | 20.8 mm |
| Connector Type | Unscrewable SAE connector |
| Middle Electrode | Nickel |
Decoding the Thread Size (M14 x 1.25)
- M14: This indicates that the spark plug has a metric thread with a nominal diameter of 14 millimeters. This is the diameter of the thread itself.
- 1.25: This number represents the thread pitch in millimeters. The thread pitch is the distance between one thread and the next. A pitch of 1.25 mm means that for every full rotation, the spark plug will advance 1.25 mm into the spark plug bore.
Significance of Thread Length (19.0 mm)
The thread length of 19.0 mm is also critical. It ensures that the spark plug's tip reaches the correct position within the combustion chamber without fouling or interfering with the piston. Using a spark plug with an incorrect thread length can lead to:
- Too short: Poor combustion, carbon buildup, and potential misfires as the spark tip is recessed.
- Too long: Contact with the piston or valves, causing severe engine damage.
Other Key Details
- Spanner Size (20.8 mm): This specifies the size of the wrench or socket needed to install or remove the spark plug.
- Unscrewable SAE connector: This refers to the terminal at the top of the spark plug where the ignition coil wire connects. It indicates that the top nut can be unscrewed if a different type of connector is required (e.g., for certain older vehicles or specific ignition systems).
- Nickel Middle Electrode: Nickel alloy is a common material for standard spark plug electrodes due to its durability and cost-effectiveness, providing reliable performance for a wide range of applications.
Understanding these specifications helps in selecting the correct replacement spark plug for your engine, ensuring proper fit, function, and longevity.
