c1938 Hispano-Suiza 12Y Supercharged 36 liter 12-cylinder 1,000 hp class aero-engine,Engine number A80263
The Hispano-Suiza 12Y was a French aircraft engine in the pre-WWII era. The 12Y became the primary 1,000 hp (750 kW) class engine and was used in a number of famous aircraft, including the Morane-Saulnier M.S.406 and Dewoitine D.520. Its design was based on the earlier and somewhat smaller, 12X. A further development was underway, the 12Z, but ended due to the German occupation of France.
A real effort to improve the performance of the engine in 1938 resulted in the Hispano-Suiza 12Y-45, which used the S-39-H3 supercharger co-designed by André Planiol and Polish engineer Joseph Szydlowski. The Szydlowski-Planiol device was larger, but much more efficient than the more primitive Hispano-Suiza models. When used with 100 octane fuel, the supercharger boosted to the -12s 7:1 compression ratio, increasing power to 900 hp (670 kW). Combined with the fully adjustable Ratier propeller, this allowed the D.520 to perform as well as contemporary designs from Germany and England.
Another improvement in supercharging led to the Hispano-Suiza 12Y-49, whose performance improved from 850 hp (630 kW) at sea level to 920 hp (690 kW) at just over 10,000 ft (3,000 m). This improvement in power with altitude was a common feature of most engines of the era, the result of the supercharger "robbing" power at low altitudes.
This Hisapno Suiza 12Y is offered form a long term European Museum collection. It is nicely painted and appears to be complete thought the attahed prop is likely a bit earlier than the engine. It is fitted to a custom made stand and and has one valve cover mounted in an open position to allow viewing of the cam area.
A truly impressive piece this 36 liter 1,000 HP class "Hisso" would be a striking addition to any mechanical collection or a priceless back up for the appropriate aircraft.