Cast Iron Engine Block Filler (Hard Blok & Moroso Predecessor)

EPOXY54 was originally engineered to reinforce aluminum engine blocks, with a thermal expansion rate closely matched to aluminum for long-term stability under extreme heat and load. However, over time, real-world use has shown that EPOXY54 can also perform effectively in cast iron applications when applied correctly.

Proven Use in Cast Iron Platforms

Despite its aluminum-focused formulation, EPOXY54 has been successfully used by customers across a wide range of cast iron engines, including:

  • Small Block Chevrolet (SBC)
  • Toyota 2JZ-GTE
  • LS-based variants
  • Top Fuel drag bikes
  • Other high-output iron-block platforms

These applications span everything from drag racing to extreme power builds, demonstrating the epoxy’s strength, adhesion, and durability in demanding environments.

Why It Works in Cast Iron

One important factor often overlooked is that many aluminum engine blocks already contain cast iron cylinder liners. In these engines, EPOXY54 is routinely in direct contact with cast iron, yet continues to perform reliably under high cylinder pressure and repeated thermal cycles.

With proper surface preparation—thorough cleaning and degreasing, EPOXY54 forms a strong, permanent bond to cast iron surfaces. This allows it to reinforce cylinder walls, reduce bore distortion, and improve overall block integrity.

Real-World Results Matter

From boosted street cars to record-setting drag machines, EPOXY54 has proven itself in environments far beyond the lab. Its continued success in both aluminum and cast iron platforms comes from real customer data—not theory.

Final Thoughts

If you’re reinforcing an aluminum block, EPOXY54 is purpose-built for the job. If you’re working with cast iron, the product has a strong track record when applied correctly and used in appropriate applications.

If you’re unsure whether EPOXY54 is right for your specific engine or use case, reach out to us—we’re happy to help you make the right call before you build.

 

Shop EPOXY
https://epoxy54.com/products/epoxy54

Back to blog