The Opel cam-in-head engine (CIH) is a family of automobile engines built by former General Motors subsidiary Opel from 1965 until 1998, appearing extensively in Opel/Vauxhall badged cars during this period. Both four- and six-cylinder inline configurations were produced. The name derives from the location of the camshaft, which was neither cam-in-block nor a true overhead camshaft. In the CIH engine the camshaft is located in the cylinder head but sits alongside the valves rather than above them, so therefore effectively is still an overhead valve design. The valves are actuated through very short tappets and rocker arms. The engine first appeared in the Opel Rekord B in 1965, and was largely replaced in four-cylinder form by the GM Family II unit as Opel/Vauxhall's core mid-size engine in the 1980s, with the six-cylinder versions continuing until 1994 in the Omega A and Senator B. A large capacity 2.4L four-cylinder version continued until 1998.

The Opel Rekord D series is a Executive car that replaced the Rekord C on Opel's Rüsselsheim production lines during the closing weeks of 1971 and launched on the West German market at the start of 1972. It shared its wheelbase and inherited most of its engines from its predecessor, but the bodies were completely new. Also new, announced in September 1972, was the option of a diesel powered Opel Rekord. Early advertising and press material called the new car the "Opel Rekord II" but in due course, the "Rekord II" appellation was quietly dropped and the Rekord D was replaced at the end of the 1977 summer holiday shut down by the Opel Rekord E.