Sierra 18-8822-1 MagForce Spark Plug Wire Set, Replaces 84-816608Q81, for Mercruiser 5.0L/5.7L Delco EST Sterndrives 1993-2005

The Sierra 18-8822-1 is a MagForce spark plug wire set built for Mercruiser sterndrive engines equipped with the 5.0L or 5.7L V8 Delco EST ignition system, model years 1993 to 2005. Sierra designed the MagForce line to be "electronics friendly," protecting sensitive onboard electronics and engine control systems from radio frequency interference (RFI) and electromagnetic interference (EMI) while still delivering maximum voltage to the spark plugs.

Each wire uses a Kevlar core for durability and long service life, paired with a stainless steel wound conductor that supports maximum horsepower and engine performance. The set is finished with premium silicone jacketing and silicone boots for high-temperature protection, along with corrosion-resistant stainless steel spark plug and distributor terminals for reliable conductivity. Moisture-proof, molded distributor insulators and a high-quality conductive center carrier reinforcement keep the conductor path intact, and a screw-down cap secures the distributor connection. The Mag/Wire wound core is engineered to deliver maximum voltage without generating RFI or EMI, protecting nearby electronic devices and engine controls.

This wire set is an exact-fit design intended for straightforward installation and reliable, trouble-free service, replacing worn or original-equipment wiring on covered Mercruiser applications.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8822-1
• Product Line: MagForce
• Material: Kevlar core, stainless steel wound conductor, silicone jacketing
• Wire Diameter: 0.5 millimeters
• Item Dimensions: 0.39 x 0.39 x 0.39 inches
• Connector Type: Terminal-style
• Weight: 1.73 pounds
• UPC: 808282204013
• Category: Mercruiser Spark Plug Wires
• Fitment: Mercruiser 5.0L and 5.7L V8 Delco EST sterndrive engines, 1993 to 2005
• OEM Cross Reference: 84-816608Q81, 84-816608A81

Fitment

• Mercruiser 5.0L V8, Delco EST ignition, 1993 to 2005
• Mercruiser 5.7L V8, Delco EST ignition, 1993 to 2005

Replaces (OEM)

• 84-816608Q81
• 84-816608A81

Frequently Asked Questions

What engines does the Sierra 18-8822-1 spark plug wire set fit? The Sierra 18-8822-1 is designed for Mercruiser sterndrive engines with the 5.0L V8 or 5.7L V8 Delco EST ignition system, covering model years 1993 to 2005.

Does the 18-8822-1 wire set fit 7.4L or 8.2L Mercruiser engines? No. The 5.0L and 5.7L V8 Delco EST engines use part number 18-8822-1, while 7.4L and 8.2L V8 Delco EST engines use a different Sierra part number, so buyers with those larger engines should confirm they are ordering the correct wire set for their displacement.

What OEM part numbers does the Sierra 18-8822-1 replace? The Sierra 18-8822-1 MagForce spark plug wire set replaces Mercruiser Stern Drive OEM numbers 84-816608Q81 and 84-816608A81.

What is the wire set made of? Each wire in the 18-8822-1 set uses a Kevlar core with a stainless steel wound conductor, wrapped in premium silicone jacketing with silicone boots, and terminates in corrosion-resistant stainless steel spark plug and distributor terminals.

Will this wire set cause interference with my boat's electronics? No. The MagForce design of the 18-8822-1 is built to be electronics friendly, using a Mag/Wire wound core and superior RFI suppression to protect sensitive electronic devices and engine control systems from radio frequency and electromagnetic interference.

How many spark plug wires are included in the 18-8822-1 set? The Sierra 18-8822-1 is a complete spark plug wire set sized for an 8-cylinder Mercruiser 5.0L or 5.7L Delco EST engine, including a screw-down distributor cap connection.

What are the dimensions and weight of the 18-8822-1 wire set? The Sierra 18-8822-1 has item dimensions of 0.39 x 0.39 x 0.39 inches per wire component and a total product weight of 1.73 pounds.

Is the Sierra 18-8822-1 a genuine Sierra part or an aftermarket copy? The 18-8822-1 is a genuine Sierra MagForce spark plug wire set, engineered as an exact-fit replacement for the listed Mercruiser OEM wiring rather than a generic aftermarket substitute.

How does the 18-8822-1 protect against moisture and heat? The set uses moisture-proof, molded distributor insulators along with premium silicone jacketing and boots that provide high-temperature protection for the ignition wiring.

Is installation of the Sierra 18-8822-1 straightforward? Yes. The 18-8822-1 uses an exact-fit design intended to allow easy installation and years of trouble-free service on covered Mercruiser Delco EST engines.

Why does the wire set have a screw-down cap? The screw-down cap on the Sierra 18-8822-1 secures the distributor connection, helping maintain a reliable, moisture-resistant electrical connection at the distributor.

What year range does the 18-8822-1 cover? The Sierra 18-8822-1 covers Mercruiser 5.0L and 5.7L V8 Delco EST sterndrive engines built from 1993 through 2005.