Ls vs Hemi Comparison: Achieving 700+ Hp with Forged Internals and High-flow Heads

The debate between LS and HEMI engines has been a hot topic among automotive enthusiasts, especially those looking to achieve high horsepower figures. In this article, we will compare the two engine platforms, focusing on how to reach 700+ horsepower using forged internals and high-flow heads.

Understanding LS and HEMI Engines

The LS engine family, originating from General Motors, is known for its lightweight design and efficient performance. The HEMI, produced by Chrysler, is famous for its distinctive hemispherical combustion chamber and powerful output. Both engines have loyal followings and unique characteristics that make them suitable for high-performance builds.

LS Engine Characteristics

LS engines are popular in the aftermarket community due to their:

  • Lightweight aluminum construction
  • High-revving nature
  • Availability of aftermarket support
  • Versatile applications in various vehicles

HEMI Engine Characteristics

HEMI engines are recognized for their:

  • Powerful torque delivery
  • Robust design
  • Distinctive performance characteristics
  • Strong heritage in motorsports

Achieving 700+ Horsepower

To reach the 700+ horsepower mark, both LS and HEMI engines require specific modifications. Below, we outline the essential components needed for each engine type.

Forged Internals

Forged internals are critical for high horsepower builds as they provide the strength necessary to handle increased power and boost levels. Key components include:

  • Forged pistons
  • Forged connecting rods
  • Forged crankshafts

High-Flow Heads

High-flow cylinder heads are essential for maximizing airflow and improving engine efficiency. When selecting heads, consider:

  • Ported and polished designs
  • Larger valves for increased airflow
  • Compatible camshaft profiles for optimal performance

Comparing LS and HEMI Builds

Both engine platforms can achieve impressive horsepower figures, but their methods and results can differ. Here, we compare typical builds for each engine type.

Typical LS Build for 700+ HP

A typical LS build to achieve 700+ horsepower may include:

  • LS3 or LS7 engine block
  • Forged internals
  • High-flow CNC-ported heads
  • Aftermarket camshaft
  • Boost from a supercharger or turbocharger

Typical HEMI Build for 700+ HP

A typical HEMI build to achieve 700+ horsepower may include:

  • 5.7L or 6.4L HEMI engine block
  • Forged internals
  • High-performance cylinder heads
  • Aftermarket camshaft
  • Forced induction setup (supercharger or turbocharger)

Performance Considerations

When building either engine for high horsepower, several performance considerations come into play:

  • Fuel quality and management
  • Engine tuning for optimal performance
  • Cooling systems to manage increased heat
  • Transmission and drivetrain upgrades to handle power

Conclusion

Both LS and HEMI engines have the potential to achieve 700+ horsepower with the right modifications. By utilizing forged internals and high-flow heads, enthusiasts can unlock incredible power and performance from either platform. Ultimately, the choice between LS and HEMI may come down to personal preference, vehicle application, and desired performance characteristics.