Engines that never quite were

[wuzak]

What piston aero engines were developed on under development prior to and during WW2 that didn't make production?

Mainly interested in engines that could have proved successful if they had been allowed to continue (be it during or after the war) or could have been available earlier (if that was technically possible).

One for me is the Rolls-Royce Pennine. First run in 1944, it gave 2750hp @ 3500rpm, +12psi boost (54.4inHg MAP), from its 2750ci early in its development. for a weight of 2850lbs. The Pennine was an air cooled, sleeve-valve X-24 engine.

For comparison, the R-2800 could get 2800hp at around the same time using ADI and more boost, with a 500 pounds weight saving for the -77 used in the P-47N. The R-2800-77 was a single speed, single stage engine, whereas the Pennine was a two speed single stage engine, with fan cooling.

The other major difference was size - the Pennine was 37.5" high x 39.0" wide x 106" long. The R-2800 was approximately 52.5" in diameter (depending on accessories) x 78" long (for single speed single stage version). Thus the Pennine had a lower frontal area, but was much longer.

The Pennine may have made for a good post war civilian airliner engine, to compete with the R-3350 and Bristol Centaurus. Available earlier it could have been a good bomber engine. Imagine a Lancaster successor with 4 x 2800hp Pennines!

 

[Gixxerman]

I've seen some very interesting stuff that never quite madfe it in the litterature.
The Pratt Whitney sleeve-valve H3730 for instance, canned when, apparantly 3300hp was possible 4,000hp was imminent (according to Bill Gunston's book 'The development of Piston Aero Engines'.

 

[gjs238]

First run in 1937.

 

[yulzari]

Armstrong Siddeley Deerhound, Boarhound and Wolfhound.

 

[fastmongrel]

Armstrong Siddeley Deerhound, Boarhound and Wolfhound.

You beat me to it. A fascinating series of never quite made it engines. Another engine that never quite made but lead onto greater things the Metrovick F2 axial jet enginesMetropolitan-Vickers F.2 - Wikipedia, the free encyclopedia

 

[wuzak]

You beat me to it. A fascinating series of never quite made it engines. Another engine that never quite made but lead onto greater things the Metrovick F2 axial jet enginesMetropolitan-Vickers F.2 - Wikipedia, the free encyclopedia

And the F1 from which it was developed.

I did specify piston aero engines, however.

 

[fastmongrel]

And the F1 from which it was developed.

I did specify piston aero engines, however.

Ooops sorry reading this on a tablet and missed that bit. Thats my excuse and I am sticking with it

In that case the Rolls Royce Cecy 2 stroke apparently it sounded like the soundtrack from Hell

 

[GrauGeist]

The Jumo222 comes to mind...

When they gave up on it's development, it took down a whole line of bomber designs

 

[johnbr]

Or the BMW 802 the designer said they could get 3000hp with now trouble.

 

[bob44]

How bout the 2 stage Allison?
From what I read, it had similar power as the 2 stage Merlin, developed near the same time as the Merlin?

 

[wuzak]

How bout the 2 stage Allison?
From what I read, it had similar power as the 2 stage Merlin, developed near the same time as the Merlin?

It made it into production.

 

[Capt. Vick]

How about the engine that powered the XP-47H?

From Wiki:

"Chrysler developed their first experimental hemi engine for the Republic P-47 Thunderbolt fighter aircraft. The XIV-2220 engine was an inverted V16 rated at 2,500 hp (1,860 kW). The P-47 was already in production with a Pratt Whitney radial engine when the XIV-2220 flew successfully in trials in 1945 as a possible upgrade, but the war was winding down and it did not go into production. However, the exercise gave Chrysler engineers valuable research and development experience with two-valve hemi combustion chamber dynamics and parameters."

 

[wuzak]

The XIV-2220 was 40" longer than the Griffon, which was roughly the same capacity and power!

 

[Capt. Vick]

Good thing it was not brought to production then!

 

[timmy]

Well Ford's GAA V12 should be mentioned

Ford invested heavily on its design to compete with the Alison and Merlin. It was rejected because they didn't want to start another supply line for the new engine
A shame because all the specs point to it being much more advanced than the other two. It would have been interesting to see what HP it would have produced

Anyway what was a loss to the Airforce turned out to be a big win for the Army. The V8 version went on to be the Sherman Tanks best Engine. This Light powerful 450-500hp engine also proved to be super reliable

 

[johnbr]

There was also the little no-en DB H-16 of 2000hp.

 

[R Pope]

The Chrysler XIV-2220 was not built for the XP-47H. The two examples of this plane were the test beds for the new engine. The Jug was the only available single engine airframe that was big enough to handle Chrysler's first Hemi!