Chrysler 5.7L Hemi V-8

The engine's greatest disadvantage, at least for truck applications, is its sharp torque curve that peaks at relatively high engine speeds. This characteristic lacks the low end torque favored in applications where towing and hauling needs are frequent and requires operating at higher engine speeds to realize the engine's full performance. On the contrary, the engine produces respectable peak horsepower and torque considering it displaces a mere 345 cubic inches. To help with emissions and address flame propagation concerns inherent of most engines with hemispherical combustion chambers, the 5.7L utilizes a dual spark plug design with a secondary spark plug firing at the start of the engine's power stroke.

The 5.7L Hemi underwent many changes for the 2009 model year, including a higher compression ratio, active intake manifold, variable camshaft timing, and a multi-displacement system (MDS). The active intake runner system allows the engine to utilize short and long runners in the intake manifold. To increase low end performance, the short intake runners are blocked off and air flows through the long intake runners at low engine speeds. At higher engine speeds, the intake manifold opens up the short runners for improved top end performance. The multi-displacement system deactivates cylinders 1, 4, 6, and 7 under low load conditions to improve fuel economy.

5.7L Hemi V-8 Specs

5.7L Hemi V-8 Horsepower and Torque Curves