The engine comes from the same lineage as the BMC-developed E-series family introduced in the 1969 Austin Maxi, but with important modifications in order to facilitate compatibility with a conventional "end-on" transmission unit, in place of BMC/BL's traditional "gearbox-in-sump" configuration for its front wheel drive vehicles. The gearbox flange was redesigned to accept either a Volkswagen manual gearbox (for the Maestro/Montego), or the PG-1 transmission (for the Rover 200).
The engine is derived from the BMC E-series family, first introduced in the 1969 Austin Maxi. However, it has been modified to work with a conventional "end-on" transmission unit instead of the traditional "gearbox-in-sump" configuration used by BMC/BL for their front-wheel drive vehicles. The gearbox flange was redesigned to accept either a Volkswagen manual gearbox or the PG-1 transmission.