No engine existed at the time with a suitable level of power combined with a low weight.

The Aircraft Disposal Company, also known as Airdisco and ADC, were producing the low-cost Airdisco V8 which had been developed by Frank Halford from their large stocks of war surplus Renault V8 aero engines.

The original Cirrus engines were all designed by Halford and built by ADC.

De Havilland launched his product as the Cirrus Moth and it proved a winning combination.

[2][3] ADC ceased manufacture when it ran out of surplus Renault engines around 1928.