Complex sentence: In 1989 the 944S2 was introduced, powered by a normally aspirated, dual-overhead-cam 16-valve 3.0L version of the 944S engine, bore, stroke, the largest production 4-cylinder engine of its time.
Split into simpler sentences: In 1989 the 944S2 was introduced, powered by a normally aspirated, dual-overhead-cam 16-valve 3.0L version of the 944S engine. With a bore of and a stroke of, it was the largest production 4-cylinder engine of its time.