View Full Version : Forgotten Hispano-Suiza 12Y

02-25-2006, 04:25 PM
In Many case the french aviation wich for the time was the most advanced influenced so many aircraft makers. Ofcourse you will never find this in Aircraft makers an other example is the Spitfire, P51,macchi 202 etc...
I'll take one minute of silence for what the French Aviation technologie did for many aircraft to come later on.

Hispano-Suiza 12Y

The Hispano-Suiza 12Y was a French aircraft engine in the pre-WWII era. Developed from the earlier, and somewhat smaller, 12X, 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, Dewoitine D.520. The design was also widely used in other countries, and formed the basis for licensed production of a number of designs, most notably the Soviet Klimov VK-105 series.

The 12Y was a fairly traditional in construction, a 36-litre water-cooled V-12 with the two cast aluminium cylinder banks set at 60 degrees to each other. A unique feature was that the cylinder heads were not removable, instead the entire block could be quickly removed from the engine. This made it somewhat famous for being entirely leak-proof, a design that was considered by other designers and almost became a part of the Rolls-Royce Merlin. The major design change from the earlier 12X was to use a master-articulated cylinder rod system, instead of the fork-and-blade type. A single overhead camshaft drove the valves, which were filled with liquid sodium for cooling. Only a single intake and exhaust valve were used, unlike most designs of the era which had moved to four valves per cylinder. A single-stage, single-speed supercharger was standard, although the art of designing a useful intake was not as well developed as in other countries, and altitude performance was always lacking.

The first 12Y test articles were constructed in 1932, and almost instantly the entire French aviation industry started designing around it. At the time the engine developed only 760 hp (570 kW), but it was clear it had potential to the 1,000 hp (750 kW) class. An early modification led to the 12Ycrs which used a hollow propeller shaft to allow a 20mm cannon to fire through the propeller spinner (what the Germans called a motorkanone). All later designs shared this feature. The 12Ydrs was the next major series, with a basic rating of 836 hp (623 kW) at sea level with a compression ratio of 5.8:1, while the 12Y-21 offered 867 hp (647 kW) from a 7:1 ratio.

In 1936 the connecting rod design was changed slightly to create the 12Y-31, but the low compression ratio was retained and the power was increased to only 850 hp (630 kW). Nevertheless this became one of the most used engine designs of the pre-war era, used in almost all fighter designs and prototypes.

A real effort to improve the performance of the engine in 1938 resulted in the 12Y-45, which used the Polish-designed Szydlowski-Planiol S-39-H3 supercharger in place of the indifferent French models. This allowed the compression ratio to be raised to that of the -21's 7:1, boosting power to 900 hp (670 kW), although requiring the use of 100 octane fuel. 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 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 many early engines, the result of the supercharger "robbing" power at low altitudes to provide boost that then had to be dumped to avoid overboosting the engine.

The final major version was the 1,084 hp (808 kW) 12Y-51, which had just started into production when France fell in 1940. The -51 was the first version that came close to the performance limits of the engine, although the supercharging still meant that it was unable to compete with designs from England and Germany above 15,000 ft (5,000 m).

In the mid-1930s, Russian engineer Vladimir Klimov was sent to France to obtain a license for local production of the 12Y. A series of design changes were added to cope with cold weather operation, and the engine entered production in 1935 as the M-100 with about 750 hp (560 kW). However a series of continual upgrades increased the allowable rpm from the 12Y's fairly low 2,400 to 2,700, thereby increasing power to 1,100 hp (820 kW). The resulting design, the M-105, became one of the major Soviet engine designs during the war. In 1941 designers were allowed to attach their own names to their designs, and the engine became the VK-105.

The 12Y design was further modified to create the somewhat more modern 12Z, but production had not yet started when France fell.


For 12Ydrs:

Layout: 12-cylinder two-row vee
Bore by stroke: 150 by 170 mm
Displacement: 36 l (2,197 in‚¬≥)
Compression ratio: 5.8:1
Power: 890 hp (664 kW) at 2400 rpm at sea level, 930 hp (700 kW) at 2,950 ft (900 m)
Weight: 470 kg (1036 lb)

02-25-2006, 05:09 PM
What is really interesting about the 12Y is size of the displacement of the engine in relation to its overall weight.

While the Merlin and V-1710, displaced 27 and 28 litres respectively, they weighed around 730 kilograms each. The DB 601 displaced about 34 litres and weighed around 600 kg. The DB 605 displaced around 35.7 litres and weighed around 760 kg.

The H-S 12Y displaced around 36 litres but was an incrediably light 470 kg. Shaving 150-300 kg of weight off a fighter is not an inconsiderable achievement, especially when the engine produced close to 1100 hp in its final versions.

02-25-2006, 05:19 PM
Ofcourse the engine recieved some more power Hispano-Suiza 12Z engine of 1,600 hp then came out with different code names. we know who got it .

02-25-2006, 06:21 PM
The 12Z was a development of the 12Y, not really the same engine, although they shared many similar characteristics. Sort of like how the DB 601 and DB 605 are related. It was much heavier, used a different valve/cylinder set up and had higher compression ratios.

Best power was around 1,500 hp, but I have read that some test beds were doing 1,600hp in mid-1940. It remains to be seen whether they could of been workably implemented into a fighter and still maintain that power. The engines fitted to some of the D.520 developments were supposed to make 1,500 hp but supercharger and impeller limitations cut that to around 1,280 hp and even then the engines reportedly had trouble keeping rated power.

The 12Z engines had lots of problems delivering their rated power with any sort of reliability. Spain used -17s and -89s in several aircraft post war, mostly licence built 109s. None of them seem to have operated at more than 1,300 hp

02-26-2006, 01:25 AM
Check the motor specs FYI http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

02-26-2006, 08:59 AM
Lol the SpitYak the ultimated noob plane.... jk nice plane

02-26-2006, 10:47 AM
Merciles we can do with out your JK thx.

03-01-2006, 07:10 AM
For the sake of argument, at what point does it quit being the original creators idea?
The wood wheel was first, and I got some nice 18" on my SUV. My Win model 70 has several features of the original M-98 Mauser, but I dont see any royalties paid.

03-01-2006, 07:13 PM
Originally posted by ImpStarDuece:
What is really interesting about the 12Y is size of the displacement of the engine in relation to its overall weight.

The Merlin displaced 27 litres and weighed 730 kg.
The DB 601 displaced 34 litres and weighed 600 kg.
The H-S 12Y displaced around 36 litres and weighed 470 kg

See a pattern here? The bigger the holes you drill in a cylinder block the more weight you lose. Is that so clever?

03-02-2006, 04:51 AM
The single stage Merlins displaced some 27 liter, and weighted a bit over 600kg.

The two stage Merlins displaced the same 27 liter, and weighted a bit over 740kg...

Hint, hint...

BTW, what does the Hispano Suiza engine weights include...? Superchargers, magnetos, built-in oil tanks, reduction gears and so on, ie. accessories can weight several hundred kgs and I simply believe the HS weights are given without these weights.

The DB 601A for example weighted some 590kg, but this was understood w/o reduction gear (which was removeable on that early version), and all in all, the whole 'power egg' (ie. complete engine cowling, 'ready to go', with propeller etc. was weighting little over 1000kg.

In brief, be sure not to compare apples to oranges..

03-02-2006, 07:22 AM
Originally posted by BerkshireHunt:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ImpStarDuece:
What is really interesting about the 12Y is size of the displacement of the engine in relation to its overall weight.

The Merlin displaced 27 litres and weighed 730 kg.
The DB 601 displaced 34 litres and weighed 600 kg.
The H-S 12Y displaced around 36 litres and weighed 470 kg

See a pattern here? The bigger the holes you drill in a cylinder block the more weight you lose. Is that so clever? </div></BLOCKQUOTE>

Hate to buck the trend but:

The Jumo 213 displaced 35 litres and weighed 920 kg.
The DB 605 displaced 35.7 litres and weighed 760 kg
The RR Griffon displaced 36 litres and weighed 900 kg.
The DB 603 displaced 44.5 litres and weighed 920 kg.

So engines of comprable form and displacement, weigh anywhere from 300 to 450 kg more.