The CMT-EZ3 is a zinc engine anode (E3 style) with 1/2″ UNC thread, designed to protect internal engine cooling systems from galvanic corrosion. Installed in the engine block or heat exchanger, it acts as a sacrificial elementcorroding first to protect critical internal components.

This is an anode-only replacement (no brass plug), intended for use with existing pencil anode housings.

Key Features

E3 style engine anode
1/2″ UNC threaded zinc pencil
Marine-grade high-purity zinc construction
Designed for saltwater applications only
Direct replacement for existing plug assemblies

Engine Compatibility

Commonly used in:

Inboard marine engines
Heat exchanger systems
Raw water-cooled engines

Found in:

Volvo Penta
MerCruiser
Yanmar
Crusader

Fits systems using E3-size pencil anodes

Serial Number Fitment Notice

Always confirm:

Thread size (1/2″ UNC)
Anode length and diameter
Whether system uses anode-only vs full plug assembly

Typical E3 dimensions:

Approx. 2″ length 3/4″ diameter

When This Part Needs Replacement

Anode is 50% or more consumed
Heavy scaling or deterioration
Reduced cooling efficiency
Routine seasonal maintenance

Installation Notes

Remove old anode from existing brass plug
Clean threads and inspect housing
Install new anode securely
Do not overtighten
Inspect regularly in saltwater use

Alternate / Cross-Reference Part Numbers

Camp Company: CMT-EZ3
Martyr: CMEZ3
Common references: E-3Z, CME3Z

Parts Desk Insight

E3 anodes are a common mid-size pencil zinc used across many engines. They strike a balance between lifespan and fitment flexibilityideal for customers who want longer intervals than smaller E1 sizes without stepping up to larger E4 assemblies.