Porsche developed an already existing engine instead of creating a new one from scratch. The powerplant, a
twin-turbocharged six-cylinder
boxer engine with an air-cooled block and water-cooled heads, displaced 2.85 liters, about half a liter less than a contemporary 911 engine. The motor had originally been developed for the "
Moby Dick" race car and then been redeveloped slightly for the short-lived Porsche Indy Car and several other projects before being "tweaked" a last time for use in the 961, the 959's racing counterpart. The
water-cooled cylinder heads combined with the
air-cooled block, 4-valve heads and sequential turbochargers allowed Porsche to extract 331 kW (444 hp) from the compact, efficient and rugged power unit
[3]. The use of sequential twin turbochargers rather than the more usual identical turbochargers for each of the two cylinder banks allowed for smooth seamless delivery of power across the engine RPM band, in contrast to the abrupt on-off power characteristic that distinguished Porsche's other turbocharged engines of the period. The engine was used, virtually unchanged, in the 959 road car as well.
