M.1/30 permitted any suitably rated British engine that had passed a 100-hour service-type test. Designers therefore had a choice of engine within those conditions. The specification suggested two engine types. Neither came to the fore in the subsequent development described in the video.
Notable Point · 1:34-1:51
M.1/30 engine choice and the 100-hour service test
Any suitably rated British engine could qualify after a 100-hour service-type test, while neither of the two suggested types came to the fore.