This took some finding but there is a connection between Datsun and BMC, you may find the link interesting.
The arrangement was extremely generous with Austin provide every assistance possible including materials, drawings, specifications and importantly patented technology that the Japanese company was able to use in its other products. From then until 1960 Nissan produced 21,589 A40 and A50 saloons and Cambridge station wagons using the BMC ‘B’ Series engine design. While doing so Nissan gradually built up local content.
No doubt a lot of us remember the sixties and closely looking at the range of small-engined Datsun vehicles at the time and noticed the similarity between the engines and BMC ‘B’ series engine. Back then I didn’t realise the connection. Nissan actually continued to produce cars with the ‘B’ Series based engine right up to 1972.
http://www.acmefluid.com.au/larry/austinnissan.html