Quad 4 engine

The Quad 4 is a family of straight-four engines produced by the Oldsmobile division of General Motors. Several double overhead camshaft versions were made between 1987 and 2002, and a single overhead camshaft model was built from 1992 to 1994. The name comes from its four cylinders with four valves each. It was the first domestic regular-production DOHC four-cylinder wholly designed and built by GM, the only earlier example being the Chevrolet Cosworth Vega, whose head Cosworth designed in England. It was expected to debut in 1987 but was delayed a year, reached buyers as an option in the 1988 Oldsmobile Cutlass Calais and Pontiac Grand Am, and spread to Buick later in 1988 and Chevrolet in 1990. All engines were built at the Lansing Engine Plant in Delta Township, balance shafts arrived in 1995, and a 1996 revision with new bore and stroke was renamed the Twin Cam. The Ecotec replaced it after the 2002 model year.