NGK 1637 ILFR5B11 Laser Iridium Spark Plug, 14mm Thread, 26.5mm Reach

The NGK 1637 (ILFR5B11) Laser Iridium spark plug is an OE-quality iridium ignition plug built for reliable starts, stable spark and long service life. It has a precision laser-welded fine-wire iridium alloy center electrode and a platinum-tipped ground electrode. Iridium's very high melting point and hardness suit modern high-efficiency engines. The plug is also sold as an iridium tip spark plug or ILFR5B11 replacement plug.

Key Features:

• Iridium alloy center electrode: fine-wire design for consistent ignitability and reduced electrode wear
• Platinum ground electrode tip: promotes even wear, which suits distributorless ignition systems
• Copper core: improves heat dissipation and conductivity across a wide heat range
• High-grade alumina ceramic insulator: helps resist dielectric punch-through
• Trivalent metal plating: resists corrosion and seizing, which eases installation and removal
• Built-in resistor: 5k ohm, which helps suppress radio-frequency interference

Specifications:

• NGK part number: 1637
• NGK plug number: ILFR5B11
• Thread size: 14mm
• Reach: 26.5mm (1.043 in.)
• Seat type: gasket (flat) seat
• Heat range: 5
• Hex size: 5/8 in.
• Terminal: solid terminal
• Torque: 18-25.3 lb-ft in cast iron heads, 18-21.6 lb-ft in aluminum heads

NGK is a leading original equipment spark plug supplier. The Laser Iridium line is designed to meet OE standards for durability and performance, and it is rated for extended service intervals.