Champion 857 Spark Plug

Champion 857 Copper Plus Spark Plug

Champion 857 is a Copper Plus spark plug built for dependable ignition performance and steady heat control. Its copper core electrode supports conductivity and wear characteristics that matter in small-engine and older vehicle applications, including 1965-1968 Jeep Wagoneer ignition service.

The Copper Plus line focuses on practical, OE-style spark plug construction with a copper core for consistent firing and nickel electrode materials for durable operation. For Jeep Wagoneer owners searching for a Champion 857 spark plug or RH18Y replacement, this plug matches the listed application and specifications.

Key Features

• Copper core electrode for improved conductivity and heat control
• Nickel center and ground electrode tip materials
• Resistor type spark plug for ignition system noise control
• Flat seat design
• Pre-gapped to 0.025 in. / 0.64 mm
• 14 mm thread diameter with 0.438 in. reach
• Hex size: 0.813 in. / 20.650 mm
• Champion plug type RH18Y

Detailed Description

Champion 857 is a Copper Plus spark plug engineered around a copper core electrode to help maintain conductivity and manage heat transfer during operation. The nickel center electrode tip and nickel ground electrode core material support consistent spark delivery and normal wear characteristics, while the resistor design helps reduce electrical interference in the ignition system. This makes it a practical choice for service work where correct heat range, thread size, and seat style matter.

Compatible With 1965-1968 Jeep Wagoneer, N/A. This part cross-references Autolite 437 for the same application. If you are replacing a worn plug in a Jeep Wagoneer, Champion 857 provides the listed RH18Y configuration and fitment details needed for a direct-match search.

Common Problems This Part Can Address

• Hard starting caused by worn or fouled spark plugs
• Misfire from weak or inconsistent spark delivery
• Rough idle related to degraded plug electrodes
• Ignition noise concerns in resistor-equipped systems
• Heat-related plug wear from an incorrect or aging spark plug

Installation Notes and Tips

Verify the plug type, thread diameter, reach, seat type, and heat range before installation. The pre-gap is listed at 0.025 in. / 0.64 mm, but always confirm the required gap for your application before use. Check the ignition system condition, inspect the plug wires or boots, and install to the manufacturer’s torque specification for the cylinder head.

For Jeep Wagoneer service, confirm the listed RH18Y plug type and 1965-1968 application before ordering. Champion 857 is also a useful search term when comparing replacement spark plugs by part number.

Quality Assurance

Champion’s Copper Plus line is built around a copper core design for dependable performance, with nickel electrode materials and resistor construction specified for this application. The product details provided here are based on the manufacturer description and listed fitment data for 1965-1968 Jeep Wagoneer.