Fram AR474 Autolite Racing Non-Resistor Spark Plug 14mm Tapered Seat

The Autolite AR474 is a high-performance racing spark plug engineered for modified and competition engines demanding reliable ignition under extreme conditions. Featuring a copper core center electrode and a cut-back ground electrode with anti-corrosive nickel plating, this plug delivers improved ignitability, faster flame kernel growth, and superior heat transfer for maximum on-track performance.

Key Features:

• Yttrium-enhanced alloy ground electrode enables up to 8% reduction in side wire temperatures, reducing the risk of pre-ignition and improving durability
• Cut-back ground electrode improves ignitability and promotes faster flame kernel growth for consistent combustion
• Anti-corrosive nickel-plated shell resists rust and corrosion better than black oxide finishes, maintaining long-term efficiency
• High alumina multi-rib ceramic insulator provides superior thermal conductivity and insulation strength while preventing flash-over
• Non-resistor design — eliminates resistance for maximum spark energy delivery in racing applications
• Copper-glass seal bonds insulator, terminal post, and center electrode together for a 100% gas-tight, leak-proof seal ensuring full voltage at the spark gap
• Cold-formed steel shell with precision rolled 14mm x 1.25 threads for secure, reliable fitment
• Available in colder heat ranges than most plug manufacturers to support heavily modified engines

Specifications:

• Thread Size: 14mm x 1.25
• Reach: 0.708 in.
• Hex Size: 5/8 in. (16mm)
• Seat Style: Tapered
• Center Electrode: Copper Core
• Resistor: Non-Resistor
• Tip Configuration: Short Projection (Non-Projected)
• Factory Pre-Gap: 0.025 in. (0.6mm)
• Heat Range: 14

The Autolite AR474 is sold individually and is the same plug trusted by professional race car drivers in oval and road racing applications. Its colder heat range and robust construction make it the go-to choice for engines running performance modifications where stock plugs fall short.