An Experimental Alloy A Series, Made By BMC.
In the late 1950's BMC realised that their "Workhorse" engine the A series could do with a bit of a face lift. To this end they commissioned The British Aluminium Co. to investigate the possibilities of making an all Alloy A Series. This project was overseen by George Harriman with input from other BMC worthies including Issigonis. By 1963 "BA" had produced a number of these blocks in varying configurations, with blocks actually running in at least 1 Riley Elf and the project looked like it was going to go somewhere.
More here:
http://mk1-performan...mental_dept.htm
http://mk1-performan...lock-report.pdf