Finally a postwar reliable (or not) "powerful" Hispano-Suiza fighter engine ?

[Deltafan]

Hi,

I asked this around 10 years ago on a french website where a lot of french authors are présent. But nobody was able to answer.


The postwar french Hispano-Suiza 12Y and 12Z engines and foreign dérivatives (more powerful than the 935/910 HP of the HS 12Y-45/49 engines of the Dewoitine D-520 in service in 1939) were known to be not very reliable, in particular into service.

As far as I know, this reliability was not too bad with the Swiss D-3801, C-3602/3603 (12Y-51 1000/1020 HP) and the first versions of the Russian Klimov dérivatives (M/VK-105s from 1050 to 1360 HP, for the Yak-1, Lagg-1, Yak-1B, Yak-7B, Yak-9, Yak-3, ...).

As far as I Know too, the reliability was not good (and sometimes calamitous) with the Swiss D-3802, C-3604 (derivative Saurer YS-2 1250 HP), prototype D-3803 (derivative Saurer YS-3 1430 HP), Russian Yak-9U (more or less russian derivative VK-107 1650 HP), Spanish Hispano Aviacion HA-1109 J1L and HA-1112 K1L (HS 12Z-89 and 12Z-17 1300 HP), French bomber prototype Breguet 482 (HS 12Z 1350 HP), French fighter prototype Dewoitine D-520 Z (HS 12Z 1600 HP).


But I have never read a single (bad or good) line about the reliability of the Hispano-Suiza 12Z-17 (1500 HP) on the 112 Ikarus S-49 C in service in Yugoslavia from 1952 to 1960/61 (for example to compare, the D-520 Z, with two successive and defective engines, was only able to flight straight lines above the runway in 1948 before being abandoned...).

If anyone has any information about it, I will be very grateful to him

https://forum.warthunder.com/index.php?/topic/308508-ikarus-s-49/

 

[iverson]

I can't claim to be an expert by any means. But I suspect that the war had a lot to do with the reliability of developed engines.

Due to the occupation, French engines--from Hispano and Gnome-Rhone--simply lost out on the development time that benefited American and British equivalents. Post-war, there was probably little money available for development, given the availability of cheaper, proven engines from Pratt-Whitney, Rolls-Royce, Bristol, and Wright and given the and the rush to develop turbines. Where wartime development was possible--in the USSR--the basic Hisso design worked fine.

I also suspect that availability had a lot to do with the use of the Hispano in the S-49. I have read that Hispano in the Spanish Ha1109 also proved unreliable. Hence its replacement by the Merlin.

 

[Deltafan]

(...) I suspect that the war had a lot to do with the reliability of developed engines.

Due to the occupation, French engines--from Hispano and Gnome-Rhone--simply lost out on the development time that benefited American and British equivalents. Post-war, there was probably little money available for development, given the availability of cheaper, proven engines from Pratt-Whitney, Rolls-Royce, Bristol, and Wright and given the and the rush to develop turbines.

Yes, but from the end of WW1 to the beginning of WW2, the french aero-engines declined compared to the aero-engines of other western lands of engine-builders (Germany, UK, USA). For example, at the beginning of WW2, pilots of the french Armée de l'Air noticed that the engines of their american planes (in particular the engines of the Curtiss H-75 / P-36 fighters) were more powerful and more reliable than the HS and GR of the french planes (in particular those of the french fighters Bloch 152, MS 406 and D-520).

Where wartime development was possible--in the USSR--the basic Hisso design worked fine.

Yes. For example, I remember that on a french website a russian specialist wrote that, at least for the Hispano-Suiza dérivatives, the Russians engines contained more oil than the french engines.

I have read that Hispano in the Spanish Ha1109 also proved unreliable. Hence its replacement by the Merlin.

Yes. But there is Nothing about the reliability of the HS 12Z-17 on the S-49C...
It can be different from a plane to another. For example the GR 14K was very reliable with the French bomber Amiot 143, but it was far less reliable with a lot of other french planes.

I also suspect that availability had a lot to do with the use of the Hispano in the S-49.

Yes. The yugoslav officials bought the HS 12Z because of an embargo of USSR against Yugoslavia and because the similarity with the S-49A's russian engine.