The first Farman engine was a water-cooled V-8 rated at 200 hp. It weighed 700 lb, or 3.5 lb/hp. The built-up, welded-steel cylinders were made in pairs. Push rods and rockers operated the valves, were enclosed by aluminum covers and fed directly with oil. The oil supply was carried in the crankcase base chamber.
Magnetos provided dual ignition and a Ragonet electric starter and an impulse magneto were fitted. The propeller was driven through bevel planetary gears of the well-known Farman design, which included one fixed crown bevel, a differential spider with four satellites, and a crown bevel wheel. A water-cooled V-12 of similar design was rated at 400 hp.
This engine soon was supplanted by a water-cooled W-12 with a 130 mm (5.118″) bore, 160 mm (6.299″) stroke, 28.485 l (1,555.2 in³) displacement and 5.5:1 compression ratio was rated 400 hp at 1,880 rpm and weighed 1,100 lb. Fuel consumption was 0.484 lb/hp/hr and oil consumption was 0.022 lb/hp/hr.
All Aero 