The Rover Group K-Series engine was introduced in 1988 as a powerplant for the Rover Metro car. It was revolutionary in that it was the first volume production implementation of the low pressure sand casting technique (LPS). This production technology overcame many of the inherent problems of casting aluminium components, and consequently permitted lower casting wall thicknesses and higher strength to weight ratios.

The engine was introduced in 1.1 L single overhead cam, and 1.4 L dual overhead cam versions. The engines were unique in being held together as a sandwich of components by long through-bolts which held the engine under compression.

Low Pressure Sand Casting works by injecting liquid aluminium into an upturned sand mould from below. In this way any oxide film always remains on the surface of the casting and is not stirred into the casting structure.