6 replies to this topic

[Bob Riebe]

https://www.enginela...hrough-history/

 

https://youtu.be/EBF08d-dUfY

[Wuzak]

The myth persists:

 

"The Rolls Royce Vulture — which was an X24 layout made up largely of two Peregrine V12 engines mated together"

 

The fact is that the Vulture predated the Peregrine, the vee angles of the Vulture were 90° while the Peregrine was a 60° V12, and the bore spacing of the Vulture was 6.1", 0.025" wider than the Merlin, and the Peregrine had a bore spacing of 5.625".

 

The Vulture did share bore and stroke with the Peregrine (and the Kestrel before it), but not much else.

[Wuzak]

Another X-engine was the Allison X-4520.

 

https://oldmachinepr...ircraft-engine/

 

 

Rather than using a master and slave rods, like the Vulture and DB 604, the X-4520 had two sets of fork and blade rods side by side on each crank pin, with the top banks offset from the bottom banks.

 

This was a possible solution for the Vulture's issues if development had continued.

 

 

The video mentions the Exe, which was small and lacked the power potential of larger engines.

 

Late in the war Rolls-Royce developed the Pennine, an X-24 of just under 2,800 cubic inches (46L), similar to the famous R-2800. It produced 2,750hp early in its development, A difference between the Pennine and the Exe (and the Vulture) was that it used a built up crank and a one piece master rod, like some radial engine, such as the R-2800.

 

Any chance of the Pennine getting into production disappeared due to the development of jet engines.

 

 

The Allison V-3420 was a coupled engine with two V-1710s geared together. This is different to the German coupled engines that proved troublesome (DB 606 - 67.8L coupled DB 601, DB 610 - 71.4L coupled DB 605, DB 613 - 89L coupled DB 603) which had two complete engines connected to a common gearbox that allowed one half to be disconnected from the output shaft.

 

Originally the V-3420 was to be the X-3420. It was to used 4 banks of the V-1710 on a common crankcase. Because of limitations, the lower cylinder banks could not go much below horizontal. The bank angles between the outer blocks was 60°.

 

Power from the X-3420 was less than double the V-1710 (V-1710 ~1,000hp at the time, the X-3420 estimated to be ~1,600hp), so Allison proposed the V-3420 instead.

 

https://oldmachinepr...ircraft-engine/

[Magoo]

As the story goes, Henry Ford I was so enamored of his X-8 engine as a replacement for the Model T that the company was paralyzed while his engineering dept. vainly attempted to make it work. Finally Edsel Ford and Sorensen wore him down and a conventional L-head four was created for the Model A. 

[mariner]

What is interseting about the Hawker Henley pic is the radiator intake layout, just like the P 51 Mustang layout with an small  seperate under-body intake. it looks a much clumsier plane than the elegant Mustong but I wonder if the rad layout gave the idea to North American?

hee Henley didn't have the super low drag NACA wing which was so critical for P 51 performance but that wing was only possible because the rad was located in the empty space in t eh rear fuselage with divergingsand converging ducts to minimize internal drag .

[Greg Locock]

The Mustang's wing was laminar flow in the wind tunnel, but https://groups.googl...9dCuBiqqk?pli=1

[Wuzak]

What is interseting about the Hawker Henley pic is the radiator intake layout, just like the P 51 Mustang layout with an small  seperate under-body intake. it looks a much clumsier plane than the elegant Mustong but I wonder if the rad layout gave the idea to North American?

hee Henley didn't have the super low drag NACA wing which was so critical for P 51 performance but that wing was only possible because the rad was located in the empty space in t eh rear fuselage with divergingsand converging ducts to minimize internal drag .

 

The Henley was based on the Hawker Hurricane. It also had a ventral radiator.

 

The successor to the Hurricane, the Tornado, made its first flight also with a ventral radiator. The Tornado experienced cooling problems due to poor airflow through the radiator, so the radiator was moved to a position under the nose. The related Typhoon (essentially the same airframe, the Tornado powered by the Vulture, the Typhoon by the Sabre).[

 

The prototype P-40, the XP-40, had a ventral radiator but this also didn't work well and the radiator was moved to under the nose.

 

The Curtiss XP-46 also had a ventral radiator. North American bought engineering data for the XP-46 from Curtiss, but that was likely too late to influence the Mustang's design (IIRC it was a government arranged purchase).

 

The Supermarine Spiteful and Seafang had laminar flow wings and wing mounted radiators. So it could be made to work.