Covered in some detail in my book 'Sentinel: The Australian Cruiser Tank'.
https://www.trackpadpublishing.com/s...ea2yXls91XK2ow (yes, yes, shameless self promotion!)
A very interesting engine. Designed by a French aeronautical engineer, Robert Perrier. One survives in the prototype AC3 held in the collection of the Australian War Memorial in Canberra, Australia.
Full marks to the Macsmotorcity garage article: it's right! Nice change for the internet: much of the 'stuff' on the AC series tanks is far from accurate.
Mike