Rolls-Royce Buzzard vs Hispano-Suiza 12Y

[wuzak]

If you have to use an older style engine in WW2, which would it be - the Rolls-Royce Buzzard or the Hispano-Suiza 12Y?

They have very similar statistics.

             Bore             Stroke         Capacity          Length          Width           Height           Weight
Buzzard  6.0" (152.4mm)   6.60" (167.6mm)   2239ci (36.7l)  75.7" (1923mm)   30.6" (777mm)  44.4" (1128mm)   1140lb (517kg)
12Y      5.9" (150.0mm)   6.69" (170.0mm)   2200ci (36.1l)  67.8" (1722mm)   30.1" (764mm)  36.8" (935mm)    1135lb (515kg)

Power wise they are both in the region of 800-1000hp.

The Hispano is physically a bit smaller, particularly in length and height (difference in induction systems?), and has the ability to mount a motor cannon through the hub.

Historically the Buzzard went no further than the 100 that were built, and its racing derivative, the R. The Hispano served for many more years and saw licence production in other countries, notably in Russia, where it was redesigned and improved.

So, if you are stuck and have to use on eor the other, which would you choose?

 

[Shortround6]

Which 12Y are you using? it started out in 1932 at 410-430 kg and the Y-51 went to 492 KG in 1939. (different sources?) I am taking from "Hispano Suiza in Aeronautics" by Manuel Lage.

I think I would go with the Buzzard.

 

[wuzak]

Seems that the Buzzard wasn't really considered for fighters - only for larger multi-engine types.

The smaller Kestrel was see as the fighter engine.

 

[Shortround6]

Seems to be consistent with the thinking at the time. A hold over from WW I. R-R Falcons were a fighter engine (big fighter) and Eagles were bomber engines. The US used Hispano V-8s in fighters and Liberties in bombers. Later Packard had two different V-12s and I don't think the larger was used in fighters.
Of course fighters in the 20s and early 30s were still armed with a pair of 20-30lb mgs and agility was highly prized so using a smaller engine fit in.