A Rebus 4-cylinder, inline engine was installed on the Moncher monoplane of 1909 and on the Radice biplane. It was based on a car engine and gave 35 hp with 120x130 mm cylinders.

-The Rebus engines were designed by the well-known and famous car racer Enrico Restelli in Milan between 1909 and 1911.

-He set up a small design office together with a friend named Buzio and designed his car-based, inline four-cylinder, side-valve engines. Safe and simple.

-A series of four Rebus engines has been located, three from 1909 and the fourth from 1911.

-1909: 30/35 CV at 1,500 rpm.
-1909: 55/60 CV at 1,500 rpm.
-1909: 70 CV.
-1911: 35/40 CV.

-Rebus is an acronym for Restelli and Buzio.

From Appendix 9: We located a photograph of a Rebus engine with four upright cylinders. No illustration could be provided in the main text.

"Rebus engine on plane, 1909"