Introduced in 1988 for the 740 GLE (and later used in the 940/960), The 16-Valve Redblock motors were offered in both a 2.0–litre Turbo (B204FT/GT) and a 2.3–litre Naturally aspirated version (B234F). The head was designed for Volvo by either Cosworth or Porsche. In addition to the 16 Valve head, these motors were equipped with twin counter rotating external balance shafts and the engine block itself differs from the 8V redblock. The block differed from the standard B230 in that the auxiliary shaft (used to drive the oil pump and distributor on models that had block mounted distributors) was replaced with an external oil pump. The 16-Valve head was itself a completely new design for Volvo: The head was of a multi-piece design featuring a separate cam carrier and lower section. The later "white block" motors can trace their head design back to the two-piece setup found in the B204 and B234. The 2.0 litre turbo variant was introduced for European markets with tax structures tied to engine displacement such as Italy. Unique to the B204 turbo was an exhaust gas pyrometer which was used to detect excessively high exhaust temperatures. When excessively high exhaust temperatures were detected, the fuel injection computer would enrich the mixture. It has a forged crankshaft, cast pistons, and connecting rods.