"DOHC 2- or 2.4 L internal combustion engine produced by Nissan in the 1980s, first in 2.4 L guise as a rally motor for the 240RS, but then later de-stroked to 2 L for general production models when the 240RS could no longer race. The 2.0 L variant was used in the Nissan Silvia/Nissan Gazelle/200SX, and DR30 Nissan Skyline. The 2.4 L variant was used in the S110 Nissan 240RS. While a 1.5 L variant was designed and a prototype built, it never actually went into production. It is acclaimed as the forefather of the CA engine. It has a magnesium head and an iron block, and was available in Japan and the UK. It was discontinued in the late 1980s due to its prohibitive cost. It is most like the CA series because of the cam-over-valve design and iron block with lightweight head. The SR series later replaced the CA in 1991 with its more economical to manufacture rocker arm type valvetrain and aluminum block"