Bosch W7AC Spark Plug - 1600cc (CT Engine Code)

The Bosch W7AC is a high-quality short-reach copper-core spark plug designed specifically for VW Type 25 (T3) models fitted with 1600 CT air-cooled engines. Known for its reliability and clean, consistent performance, this plug provides excellent ignition stability under all operating conditions.

The W7AC offers a medium-cold heat range (7), making it ideal for everyday driving and long-distance cruising while maintaining optimal thermal balance. Its 12.7 mm thread reach (short-reach design) ensures perfect fitment in the CT-code air-cooled cylinder heads without risking piston contact or thread exposure.

Built with a solid copper-core electrode, this plug offers excellent conductivity, heat dissipation, and strong spark energy — crucial for smooth idling, reliable cold starting, and fuel efficiency in classic VW flat-four engines. Bosch’s precision manufacturing and nickel-plated shell provide durability and corrosion resistance, even in the toughest air-cooled environments.

Key Features:

• Genuine Bosch W7AC short-reach spark plug
• Designed for VW Type 25 / T3 1600 CT air-cooled engines
• Medium-cold heat range (7) for balanced performance
• 14 mm × 1.25 thread, 12.7 mm reach, 21 mm spanner size
• Copper-core electrode for superior conductivity and consistent ignition
• M4 terminal type – compatible with standard VW ignition leads
• Sold each – 4 required per engine

Applications:

• VW Type 25 / T3 Bus 1.6 CT Air-Cooled (1980 – 1983)
• VW Type 25 / T3 Van 1.6 CT Air-Cooled
• Suitable replacement for Bosch W7CC and NGK B6HS equivalents in short-reach heads
• Ideal for stock and mildly tuned CT-code engines requiring reliable ignition performance

Bosch Code Explained:

• W – 14 mm thread diameter
• 7 – Heat range (2 = hot, 10 = cold)
• A – 12.7 mm (½ inch) thread reach (short reach)
• C – Copper-core electrode

Specification:

• Thread size: M14 × 1.25
• Thread reach: 12.7 mm
• Spanner size: 21 mm
• Terminal type: M4
• Electrode core: Copper
• Quantity: Sold each