Was the Hispano-Suiza 12Y the worst ≥25L V-12 of WW2?

[Admiral Beez]

Was there any V-12 aero engine of 25L (edited, was in error 35L) or greater displacement that wasn't better than the Hispano-Suiza 12Y? These could include the likes of the:

Rolls-Royce Merlin
Rolls-Royce Griffon
Packard V-1650 (licensed Merlin)
Allison V-1710
Junkers Jumo 211
Junkers Jumo 213
Daimler-Benz DB 601
Daimler-Benz DB 605
Kawasaki Ha-40 (licensed DB 601)
Fiat RA.1050 (licensed DB 605)
Klimov M-103 (based on the HS 12Y)
Klimov M-105
Klimov VK-107

 

[Elan Vital]

Was there any V-12 aero engine larger than 35L that wasn't better than the Hispano-Suiza 12Y? These could include the likes of the:

Rolls-Royce Merlin
Rolls-Royce Griffon
Packard V-1650 (licensed Merlin)
Allison V-1710
Junkers Jumo 211
Junkers Jumo 213
Daimler-Benz DB 601
Daimler-Benz DB 605
Kawasaki Ha-40 (licensed DB 601)
Fiat RA.1050 (licensed DB 605)
Klimov M-103 (based on the HS 12Y)
Klimov M-105
Klimov VK-107

Short of some ultra obscure V-12 aereo engine of that size, yes it was the worst.

Some of the engines you mention are not bigger than 35 L though. Might be fairer to put the limit at 25L or even 20L instead for all the big aircraft engines of WW2, in which case you could sorta cheat with the Fiat V12s in the CR-32/42 (not worse for the displacement, but definitely weak).

 

[Admiral Beez]

Some of the engines you mention are not bigger than 35 L though.

I've changed it to equal or greater than (≥) 35 L. I believe that covers them all.

 

[Engineman]

Was there any V-12 aero engine of 35L or greater displacement that wasn't better than the Hispano-Suiza 12Y? These could include the likes of the:

Rolls-Royce Merlin
Rolls-Royce Griffon
Packard V-1650 (licensed Merlin)
Allison V-1710
Junkers Jumo 211
Junkers Jumo 213
Daimler-Benz DB 601
Daimler-Benz DB 605
Kawasaki Ha-40 (licensed DB 601)
Fiat RA.1050 (licensed DB 605)
Klimov M-103 (based on the HS 12Y)
Klimov M-105
Klimov VK-107

I am not certain that "better" is an accurate measure to assess the 12Y. Certainly, it has the reality of quite major production and diverse variants. It also formed the basis for several major copies and developments. IMO, there are many aero-engine types that never achieved production and were considered "failures".

Eng

 

[Admiral Beez]

I am not certain that "better" is an accurate measure to assess the 12Y.

It's subjective for certain, but here's a good test. If we replaced any of the above engines with a 12Y, would the aircraft have better performance? To be fair we need to remember that the 12Y is an early war engine, so a direct comparison with the likes of the RR Griffon (first run in 1939) are unfair. But swap out the DB 601 from the Bf 109E, or the Merlin from a Spitfire Mk. II for a 12Y and I think we're in the negative.

Is there any aircraft with a ≥25L V-12 that would be better served with the 12 Y? Perhaps the early Junker Jumo range may be a contender, or the first Soviet Klimovs?

 

[Engineman]

The 12Y is a 1932 engine in early form, with major types produced by 1934. This predates virtually all your candidates.
The Spitfire II is listed with the Merlin XII is listed as a 1939 development. So, as I suggest, maybe your criteria should be defined?

Eng

 

[Elan Vital]

The 12Y is a 1932 engine in early form, with major types produced by 1934. This predates virtually all your candidates.
The Spitfire II is listed with the Merlin XII is listed as a 1939 development. So, as I suggest, maybe your criteria should be defined?

Eng

Yeah. My understanding is that it was quite useful in the 1930s because very few/no Vee engines existed in this size and power category, and to boot it could offer a 20mm autocannon at a time when fighter armament was rather light. It is really in the late 30s/WW2 that it lagged behind because considerably newer engines appeared in numbers.

 

[Shortround6]

It's subjective for certain, but here's a good test. If we replaced any of the above engines with a 12Y, would the aircraft have better performance?

No.
NO.
NO.

The 12Y was being swapped for the 12Z a the time France was falling but they never got into production during the war.
Soviets modified it into the M-105 but they added several hundred pounds, reduced the cylinder bore by 2mm to make cylinder walls stronger and changed to a 3 valve head instead of the 2 valve heads.

Edit, the Soviets, even on the M-100s, were striving for better reliability/engine life than the Hispano was giving them, even at the lower powers of the mid/late 1930s.

 

[Admiral Beez]

No.
NO.
NO.

Well said. However I have read about issues with the Kawasaki Ha-40.

Licence built DaimlerBenz V12s, what was the problem

According to Nicholas Millman in Ki-61 and Ki-100 Aces https://ospreypublishing.com/ki-61-and-ki-100-aces The Ha-140 that was supposed to power the Ki-61 II series had improved inlet flow, strengthened supercharger, higher compression and a water-methanol injection system; it suffered from...

ww2aircraft.net

 

[TM06]

The Hispano engines - like all French designs leading up to and during WW2 - were a victim of circumstance. From the privatization of the various companies, the ineptitude of the French government in the 1920's and 30's, a pressure-cooker political environment and so on.
By the time they finally figured out how to make a good version of the engine (12Y-51), France fell and the Germans forbade them from making any further improvements let alone produce them. Even still, I would tentatively call the 12Y a thoroughly mediocre engine but not truly bad, as it did have some positives to it with the 12Y-51 having some very competitive specs for 1940. The 12Z was supposed to be Hispano's big hitter and was planned to completely usurp the 12Y in all of its roles.
If things had played out differently, the 12Y would've been an important stepping stone (which it still was) on the way to bigger and better engines.

 

[Shortround6]

Very true but replacing an engine that was supposed to make 1500hp for take-off and 1250hp at 5700meters in 1943-44 with a 12Y-50 that was made 1100hp for take off and 1000hp at 3260meters pretty much means your pilots are dead on take-off regardless if the engines stays running or not.

Do not confuse the HA 40 engine with the HA 140 engine.

The HA 40 was supposed to offer 1175hp at take-off and 1100hp at 4200 meters.

Hispano 12Y engines often had trouble making their 100 hour overhaul life and dealing with 6 carbs was not easy either.
The Japanese had purchased a few 12Y or 12X engines during the 30s.

 

[Shortround6]

Basically the 12Y was about the same as RR keeping the Buzzard engine of 1928 and improving it the least amount possible until 1940 and still being able to sell it and then wonder why everyone else had passed them by.

 

[Elan Vital]

What's strange is that before 1934, Hispano Suiza had designed the Type 68 railcar engine, and while it obviously had some optimizations for ground use, it still was designed with high rpm in mind (2800-3000rpm) with a bore of 100mm and a stroke of either 100 or 120mm depending on the version. I think that even without other changes, a 12Y designed around the same principle of more reasonable stroke in particular and high rpm would already have been a fair boon considering that the 12Y had been stuck at 2400 rpm and 2500rpm with the -51.

(That Type 68 engine was sufficiently interesting to be intended for certain AFVs such as the ARL V 39 SPG and SEAM G1P battle tank).

 

[Admiral Beez]

Basically the 12Y was about the same as RR keeping the Buzzard engine of 1928 and improving it the least amount possible until 1940 and still being able to sell it and then wonder why everyone else had passed them by.

Speaking of RR, I would have liked to have seen the Dewoitine D.520 (D.521) and especially the Arsenal VG-33 (VG-40) with a RR Merlin for comparison.

 

[wuzak]

FYI, the following were not equal to, or greater than, 35L capacity:

Rolls-Royce Merlin
Packard V-1650 (licensed Merlin)
Allison V-1710
Daimler-Benz DB 601

These are:

Rolls-Royce Griffon
Junkers Jumo 211
Junkers Jumo 213
Daimler-Benz DB 605
Fiat RA.1050 (licensed DB 605)
Klimov M-103 (based on the HS 12Y)
Klimov M-105
Klimov VK-107

 

[Admiral Beez]

FYI, the following were not equal to, or greater than, 35L capacity

Silly me, I meant 25 L. I'll amend the thread. I was just trying to keep out the smaller V-12s like the 18L de Havilland Gipsy Twelve, 19L Curtiss D-12 and 21L Rolls-Royce Peregrine. I consider these smaller engines as useful but in another category.

 

[yulzari]

Was there any V-12 aero engine of 35L or greater displacement that wasn't better than the Hispano-Suiza 12Y? These could include the likes of the:

Rolls-Royce Merlin
Rolls-Royce Griffon
Packard V-1650 (licensed Merlin)
Allison V-1710
Junkers Jumo 211
Junkers Jumo 213
Daimler-Benz DB 601
Daimler-Benz DB 605
Kawasaki Ha-40 (licensed DB 601)
Fiat RA.1050 (licensed DB 605)
Klimov M-103 (based on the HS 12Y)
Klimov M-105
Klimov VK-107

Just for curiosity, is there a reason to have Rolls Royce and Packard Merlins as separate items?

 

[Admiral Beez]

Just for curiosity, is there a reason to have Rolls Royce and Packard Merlins as separate items?

They're weren't identical. Same as the Kawasaki Ha-40 (licensed DB 601) and Fiat RA.1050 (licensed DB 605) are not identical to the German engines.

 

[Shortround6]

They're weren't identical. Same as the Kawasaki Ha-40 (licensed DB 601) and Fiat RA.1050 (licensed DB 605) are not identical to the German engines.

In what significant way did they differ?
As in at any given point in time (or within 6 months) what did one do that the other could not?
And bear in mind that RR was doing by far the most development work.

Changing a carburetor or a starter motor didn't change the basic engine.

But to the original question, the Hispano was the worst V-12 of 25 liters (or even 21 liters) used in WW II in combat.
Basically it was well past it's "use by_________" date.

 

[Admiral Beez]

In what significant way did they differ?

I'm not sure about the Merlins, but I've read that the Kawasaki Ha-40 was a poor cousin of the DB 601 due to the lack of the specified supercharging system.