The Cruiser Tank Mk VIII Centaur (A27L) was a version of the Cromwell tank powered by a Liberty engine. It was not a great success itself, but many Centaurs were converted into or completed as Cromwells and in that configuration used in combat in north-western Europe.
The Centaur was really a tank that should never have been built. Late in 1940 W A (Roy) Robotham, a senior Rolls Royce designer, led a team that converted the Merlin engine into the Meteor tank engine. This work was triggered by a October 1940 meeting between Robotham and Henry Spurrier, the general manager of Leyland Motors, an old school friend. Spurrier was worried about the low power of the Liberty engine being used in new British tank designs. At first Leyland agreed to produce the Meteor, but they then backed out and decided to continue building Liberty engines. At this point the Ministry of Supply should have stepped in to force Leyland to build the much more powerful Meteor, but instead they produced a compromise. English Electric and the Birmingham Carriage & Wagon Company would produce the Meteor powered A27M Cromwell III while Leyland would produce the Liberty powered A27L, then known as the Cromwell II. The design of the A27 would be modified to allow it to take either engine. It is unclear how many Centaurs were later re-engined, but a significant number of tanks were built from scratch with Centaur hulls and Meteor engines and were designated as Cromwells.
