Renault 70 hp

In addition to French production, these engines were also built in the United Kingdom[1] and equipped the majority of British aircraft sent to France at the start of WW1.

This method of gearing allowed the engine and propeller to be run close to their optimum speeds without the additional weight penalty of a gearbox.

Engines intended for pusher aircraft were fitted with a centrifugal blower which fed cooling air over the large finned cast iron cylinders.

[3] Compared to contemporary air cooled rotary engines built by Gnome, the 70 hp Renault had a worse power to weight ratio but better fuel economy.

Engines fitted to pusher aircraft were equipped with a back mounted (opposite end from prop) centrifugal blower.