Hispano-Suiza 12Z
| Company type | Aircraft piston engine |
|---|---|
| Industry | Aerospace |
| Founded | 1939 |
| Headquarters | France / Spain |
| Products | V-12 aircraft engines |
Design and development
Building upon the earlier 12Y, the 12Z incorporated four valves per cylinder operated by dual overhead camshafts instead of two valves with a single camshaft. This modification improved volumetric efficiency and raised the maximum RPM from 2,400 to 2,700. Engineered to utilize 100 octane fuel at a higher compression ratio of 7.0:1, later versions replaced carburetors with fuel injectors, increasing output from 1,000 to 1,300 hp (750 to 970 kW) at sea level.
It maintained a single-stage, single-speed centrifugal supercharger, which restricted its all-altitude performance when compared to contemporary German and British powerplants. By substituting the original HS No.1 supercharger with a larger Szydlowsky-Planiol unit, high-altitude horsepower improved to 1,500 hp (1,120 kW) at , compared to 930 hp (690 kW) at for the 12Y-45.
Prototype manufacturing commenced in 1939 for French Air Force fighters such as the M.S.410 and D.520 (including M.S.450 and D.524 variants). However, full production of the principal model, the 12Zter, faced delays due to wartime interruptions and factory relocation. An initial batch of 70 engines ordered in 1941 aimed to equip D.520Z fighters but was halted by occupying forces. Production activities were moved to Hispano-Suiza's Barcelona facility for use in the Spanish HA-1109 fighter.
Spain placed an order for 120 units in 1943 but completed only 50 engines by late 1947. These Spanish variants operated on lower-quality 92 octane fuel, resulting in a slight power reduction to 1,280 hp (950 kW) at 2,600 rpm (with maximum take-off power rated at 1,479 hp/1,100 kW). After the war, three engines were sent back to France to support further development.
Following liberation in 1944, French development resumed with the 12Z-17 series, producing approximately 200 units by 1950. Spanish manufacturing continued through a collaboration with Enasa, fulfilling an initial order for 280 new and rebuilt engines. Due to issues related to reliability and delivery schedules, this order was reduced to 100 units; ultimately only 104 12Z-17 engines were delivered before cancellation occurred in 1955.
Variants
The design and manufacture of the engine were divided between La Hispano Suiza in Barcelona and Hispano Suiza facilities at Bois-Colombes and Tarbes, leading to various designations for the 12Z and its derivatives. Spanish serial numbers appeared in the 50XXX range, while French serials were assigned within the 10XXX series.
Type 89
- 12Z-01
- Prototype carbureted versions equipped with a single-speed HS No.1 supercharger; first tested in 1939 for use on D.524, MS.450, and D.520Z prototypes.
- 12Zbis
- Carburetor-equipped design featuring a single-speed Szydlowsky-Planiol (Turbomeca) supercharger; proposed for installation on the CAPRA R-80 trimotor.
- 12Zter
- Fuel-injected version employed by the Spanish Air Force as 12Z, designated internally as 12Z-89 by Hispano Aviación. Applied on VG 39, HS-50 prototype, second VB 10 prototype, and HA-1109J.
- 12Z-17
- The primary production variant fitted with a single-speed Turbomeca supercharger; utilized on Bre.482 and SE.520Z prototypes as well as operationally on S-49C and HA-1109K/1110K/1112K aircraft.
- 12Z-18
- Counter-rotating adaptation of the 12Z-17.
- 12Z-A
- A Spanish design from 1944 incorporating a two-speed HS No.2 supercharger intended for a large-wing Hispano HS-50 variant.
- 12Z-B
- A Spanish variant from 1944 featuring a two-stage intercooled supercharger.
- 12Z-T
- Equipped with a Hispano-Boverli (HISBO) turbocharger; planned for use on Amiot 357.
- 12Z-M
- A rebuild of the 12Zter upgraded to meet 12Z-17 standards but lacking capability for moteur-canon operation.
- 12Z-1
- Also referred to as 12Z-I; prototypes fitted with a two-speed HS No.3bis supercharger intended for SE.520Z production models.
- 12Z-11
- Also known as 12Z-II; fitted with a two-speed Turbomeca supercharger proposed for enhanced CASA 2.111 or S-49 variants.
Type 91
- 12Z-15
- This is a 12Z-17 derivative featuring an enlarged 340 mm output gear designed for the VB 10.
- 12Z-16
- Derived from the 12Z-18, this variant incorporates a bigger 340 mm output gear tailored for the VB 10.
Applications
- Arsenal VB 10
- Arsenal VG 39
- Breguet 482
- Hispano Aviación HA-1112
- Ikarus S-49C
- Morane-Saulnier M.S.450
- SNCASE SE.520Z (prototype development of Dewoitine D.520 Z)
See also
- Hispano-Suiza 12Y
- Klimov VK-103
- Klimov VK-104
- Klimov VK-105P
- Klimov VK-106
- Klimov VK-107
- List of aircraft engines
Bibliography
- Hispano Suiza in Aeronautics, Manuel Lage, 2004, SAE International, Warrendale, USA, ISBN 0-7680-0997-9
External links
- "Hispano Suiza 12B" - 1949 Flight article