Champion 842 Spark Plug

Champion 842 Copper Plus Spark Plug Overview

Champion 842 is a Copper Plus spark plug built for dependable ignition performance in secondary ignition systems. It uses a copper core electrode for improved conductivity and heat control, with nickel center and ground electrode materials for steady wear characteristics.

Compatible With 1946-1948 Cadillac Commercial Chassis, this plug is a direct fit for the listed application and is commonly searched as a Champion 842 spark plug for Cadillac Commercial Chassis service.

Key Features

• Copper core electrode for conductivity and heat management
• Nickel center electrode tip and nickel ground electrode core material
• Pre-gapped to 0.035 in. / 0.90 mm
• Flat seat design with 0.25 in. reach
• 10 mm thread diameter and 0.625 in. hex size
• Non-resistor design with removable nut terminal
• Champion Copper Plus Small Engine classification

Product Details

The Champion Copper Plus line focuses on straightforward ignition service with a copper core that helps transfer heat efficiently while maintaining consistent spark delivery. Part number 842 is built with a nickel copper alloy ground electrode and a nickel center electrode tip, giving it the material combination expected in many classic and small-engine ignition applications. For buyers searching Champion 842 or a Champion 842 spark plug for Cadillac Commercial Chassis, this part matches the listed 1946-1948 fitment and notes a plug type of UY6.

This part cross-references Autolite 104 for the same application.

Common Issues This Spark Plug Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire symptoms related to electrode wear
• Reduced ignition efficiency from excessive plug gap wear
• Heat-related plug performance issues in service use

Installation Notes and Tips

Verify the plug type, thread diameter, reach, and seat style before installation. The pre-gap is listed at 0.035 in. / 0.90 mm, but always confirm the required gap for the engine specification before final installation. Use the removable nut terminal only if it matches the ignition lead connection on the vehicle.

For 1946-1948 Cadillac Commercial Chassis applications, confirm the engine’s service requirements and inspect the ignition wire condition, distributor cap, and coil output during plug replacement. Proper torque and clean threads help maintain sealing and consistent ignition performance.

Quality Assurance

Champion is a long-established ignition brand, and the Copper Plus line is built around practical electrode materials and controlled heat transfer for dependable service life. Part number 842 is specified with clear dimensional and material data to support accurate replacement selection.