Gen III HEMI Engine Block – CGI HEMI Block (GEN III Hemi Block)

The Future of Hemi Engine Blocks Has Arrived

For decades, engine builders faced an impossible choice: cast iron blocks that were heavy and prone to cracking, or aluminum blocks that needed cylinder sleeves and distorted under boost.

Not anymore.

Our CGI (Compacted Graphite Iron) Hemi engine blocks bring OEM-grade material technology to the aftermarket for the first time. This is the same advanced iron used in NHRA Pro-Stock and NASCAR CUP Blocks. 

What Makes CGI Different?

CGI isn't just "better cast iron." It's a fundamentally superior material with a unique graphite structure that delivers:

• 75% higher tensile strength than traditional cast iron (450 MPa vs 250 MPa)
• 2.5× greater stiffness than aluminum (maintains bore geometry under extreme cylinder pressure)
• 300-500% better fatigue resistance (handles repeated high-boost cycles without failure)
• 3× less thermal expansion than aluminum (consistent ring seal from cold start to full operating temp)

Built by the Engineer Who Knows Hemi

This isn't a parts reseller importing blocks from overseas. Every CGI Hemi block is designed and manufactured under the direct oversight of Eric Cunningham, former Chief Engineer at SRT/MOPAR, where he led development of:

• Hellephant 426 supercharged crate engine (1,000+ HP)
• Ram TRX 6.2L supercharged Hemi (702 HP production SUV)
• Dodge Drag Pak - 2018 FSS National Champions NHRA and NMCA
  

No Compromises. No Cylinder Liners. No Excuses.

Aluminum blocks require cylinder liners because aluminum is too soft to provide adequate ring seal. Those liners add $160-800 in parts and labor, create thermal expansion mismatches, and become failure points under extreme boost.

CGI blocks don't need liners. The material is hard enough, stable enough, and strong enough to run direct honing—just like your factory block, but with the strength to handle 2,500+ HP.