Really powerful engine, early on, for RAF/FAA?

[Jugman]

It's an Air Corps report so "American aircraft engines" probably means just that.

 

[Shortround6]

Two more reports.

http://www.enginehistory.org/Misc/P161688.pdf

http://www.enginehistory.org/Misc/P150137.pdf

It seems the US was much more interested in the propeller than the engine and even then interest in the propeller was for test purposes as the US had nothing like it in the way of individually controlled co-ax propellers.