During WWI there was an engine that was based on a 230 BHP. It was designed in conjunction with Halford and was manufactured by Armstrong Whitworth. Around 1918 this engine came out and was tested. There is no further information on the results and applications.

-It is believed that the tests were carried out on an Airco DH4.

“RHA engine”

-This liquid-cooled engine had a 12-cylinder V of 45° only, and delivered 260 HP of power.

-H. Ricardo added a supercharger which increased the power to almost 360 HP.