Potez 6D

The Potez 6D is a six-cylinder inverted inline aircraft engine developed by the French company Potez after World War II. It was produced in both normal and supercharged versions, with the unsupercharged variant delivering 179 kW (240 hp) at 2,530 rpm. The engine was part of a series designed to replace earlier radial engines, alongside the four-cylinder Potez 4D and eight-cylinder Potez 8D.

The 6D variants included the 6D-02 (unsupercharged), producing 179 kW at 2,530 rpm, and supercharged versions like the 6D-30A and 6D-30B, which featured a centrifugal blower for increased power. The 6D-30A delivered 194 kW (260 hp) normally and 254 kW (340 hp) at take-off. These engines shared components such as pistons, cylinders, connecting rods, and lubrication systems.

The Potez 6D was used in various aircraft, including the Morane-Saulnier Alcyon, Nord Noralpha, and Nord Norécrin. Over 200 Alcyons were built, with many still operational in France by 2014. The engine's design featured a direct reduction gear, air cooling, and Y-alloy pistons.

In terms of performance, the 6D-02 variant had a compression ratio of 7:1 and a fuel consumption rate of 27.7 kg/hour at economical cruising speed. Its specifications included a displacement of 8.83 L (539 cu in) and dimensions of 1,550 mm length, 510 mm width, and 668.5 mm height, weighing 235 kg without accessories.

The Potez 6D series represented a significant step in French aviation engine technology post-WWII, offering reliable performance across various applications.