Hot on the heels of the Generation III was Generation IV. These big-bore engines are some of the largest small-blocks yet, and will quickly replace the previous generation. Displacement ranges up to 7.0 L and output to 505 hp (373 kW). Generation IV will later feature displacement on demand, a technology that allows one bank of cylinders to be deactivated. It will also offer variable cam phasing and 3-valve per cylinder designs, a novelty in a pushrod engine.

GM LS engine, GM LS engine - Generation III, GM LS engine - LS1, GM LS engine - LS6, GM LS engine - Vortec engines, GM LS engine - Generation IV, GM LS engine - L76, GM LS engine - LS2, GM LS engine - LS4, GM LS engine - LS7

Read more here: » GM LS engine: Encyclopedia II - GM LS engine - Generation IV

The Generation III small-blocks replaced the LT family in 1997. These shared the same rough displacement and bore spacing (4.4 in) as their cast iron predecessors but almost everything else was changed. The bore was reduced to 3.9 in and the stroke longer at 3.62 in for greater torque. The block was cast from aluminum (for cars) instead of iron and had a new intake and injection technology and coil-on-plug ignition. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design, and the pistons are flat instead of domed. Even the cylinder firing order was changed.See also:

GM LS engine, GM LS engine - Generation III, GM LS engine - LS1, GM LS engine - LS6, GM LS engine - Vortec engines, GM LS engine - Generation IV, GM LS engine - L76, GM LS engine - LS2, GM LS engine - LS4, GM LS engine - LS7

Read more here: » GM LS engine: Encyclopedia II - GM LS engine - Generation III